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P1002 Ignition Key-Off Timer Performance Too Slow
P1002 Ignition Key-Off Timer Performance Too Slow is a manufacturer-specific diagnostic trouble code indicating that the vehicle's control module has detected that the ignition key-off timer is taking longer than expected to complete its operation.
In simple terms, after the ignition is switched off, the vehicle's electronic systems are expected to enter their shutdown or sleep sequence within a specified amount of time.
The control module monitors this process. If the key-off timer does not progress or complete within the expected time, the module may store P1002.
The important point is that P1002 does not necessarily mean that the ignition switch or key itself is defective.
The underlying problem can involve:
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Ignition switch or ignition-status signal
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Body Control Module (BCM)
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Powertrain Control Module (PCM/ECM)
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CAN communication
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A module that remains awake after key-off
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Battery voltage
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Power-management circuits
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Parasitic electrical load
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Software or calibration problems
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Network communication faults
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A control module failing to enter sleep mode
Because P1002 is manufacturer-specific, the exact definition, affected module, timer strategy, and diagnostic procedure can differ between vehicles.
What Does P1002 Mean?
The commonly used description is:
Ignition Key-Off Timer Performance Too Slow
To understand this code, it helps to understand what happens when the ignition is switched off.
Modern vehicles do not simply turn every electrical system off immediately when the key is removed or the ignition button is pressed.
Instead, the vehicle normally performs a controlled shutdown process.
A simplified sequence may look like:
Ignition ON → vehicle operating → ignition switched OFF → key-off timer starts → modules perform shutdown tasks → systems enter sleep mode
The control module expects this process to occur within a specified time.
If the timer takes too long, does not advance correctly, or a related module prevents the vehicle from completing the expected shutdown sequence, P1002 may be stored.
What Is an Ignition Key-Off Timer?
The key-off timer is part of the vehicle's electronic power-management strategy.
After the ignition is switched off, some systems may remain active temporarily.
Examples include:
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Instrument cluster
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Radio or infotainment system
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Body control module
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Interior lighting control
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Door modules
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Security system
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Network communication
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Cooling fan control
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Power windows
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Remote locking systems
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Emissions-related modules
Some systems need a short period after key-off to save data, complete commands, close communication sessions, or prepare for sleep mode.
The key-off timer helps the vehicle determine whether the shutdown process is occurring within the expected time.
Why Does the Vehicle Need a Key-Off Timer?
Modern vehicles contain numerous electronic control modules that communicate continuously.
When the ignition is switched off, these modules need to transition from an active state to a low-power state.
This helps:
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Reduce battery drain
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Protect electronic components
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Complete data-saving operations
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Shut down communication networks correctly
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Maintain security functions
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Prepare the vehicle for the next start
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Manage delayed electrical functions
If one module remains awake or communication does not shut down correctly, the vehicle may consume more battery power than expected.
This is one reason a key-off timer fault can sometimes be associated with battery drain.
Does P1002 Mean the Ignition Key Is Bad?
No.
The wording can be misleading.
P1002 refers to the performance of the key-off timing or shutdown process, not necessarily to the physical ignition key.
A vehicle with a perfectly functioning key can still set P1002.
For example:
Ignition switched off → BCM remains active → network remains awake → shutdown takes too long → P1002
In another situation:
Low battery voltage → module communication becomes unstable → shutdown sequence is delayed → P1002
Therefore, the complete electrical and communication system should be diagnosed.
Symptoms of P1002
The symptoms depend on the cause of the problem.
Check Engine Light or Warning Light
The vehicle may illuminate the Check Engine Light or another warning indicator when P1002 is stored.
The exact warning strategy depends on the manufacturer.
Battery Drain
One of the more important possible symptoms is battery discharge.
If a control module fails to enter sleep mode after the ignition is switched off, it may continue consuming electrical power.
This can cause:
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Weak battery after sitting overnight
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Battery repeatedly going flat
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Slow engine cranking
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Difficulty starting after several days
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Battery needing frequent charging
However, P1002 does not automatically prove that a parasitic draw exists.
Delayed Electrical Shutdown
The driver may notice that certain systems remain active longer than expected after the ignition is switched off.
Possible examples include:
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Radio staying on
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Interior lights remaining active
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Instrument cluster remaining illuminated
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Cooling fan continuing to operate
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Infotainment system taking too long to shut down
Some delayed operation is normal, so the manufacturer's specified shutdown time should be used for diagnosis.
Electrical Accessories Behaving Abnormally
Depending on which module is preventing the vehicle from entering sleep mode, the driver may experience:
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Power windows operating unexpectedly
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Door-lock problems
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Interior-light issues
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Remote-locking problems
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Infotainment glitches
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Cluster problems
Intermittent Starting Problems
If P1002 is associated with a battery-drain or power-management problem, the vehicle may eventually develop starting difficulties.
The actual cause may be low battery voltage rather than the key-off timer itself.
Multiple Communication Codes
If the underlying problem is related to the CAN network, additional communication codes may be stored.
These can include manufacturer-specific U-codes or module communication faults.
No Noticeable Symptoms
P1002 may sometimes be stored without obvious driveability symptoms.
The vehicle may continue to operate normally while the control module records a shutdown-timing problem.
Common Causes of P1002
Control Module Not Entering Sleep Mode
A control module that remains awake after key-off can delay the vehicle's shutdown sequence.
Possible modules include:
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BCM
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PCM/ECM
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Instrument cluster
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Infotainment module
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Door module
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Security module
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Telematics module
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Power accessory module
The specific module depends on the vehicle.
Ignition Status Signal Problem
The control module must know whether the ignition is ON or OFF.
A faulty ignition-status signal can interfere with the key-off timer.
Possible causes include:
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Faulty ignition switch
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Damaged ignition wiring
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Poor connector
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Incorrect switch position signal
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Ignition relay problem
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Start/stop button signal problem
On push-button vehicles, the system may use electronic ignition-status information rather than a conventional mechanical ignition switch.
Faulty Ignition Switch
A worn or damaged ignition switch can occasionally fail to provide the correct key-off status.
Possible problems include:
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Internal contact wear
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Intermittent contacts
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Sticking switch
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Incorrect switch position
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Electrical resistance in the switch circuit
The switch should be tested before replacement.
Push-Button Start System Problem
Vehicles with keyless push-button ignition use electronic signals to determine ignition state.
Problems can occur with:
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Start/stop button
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BCM
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Smart-key system
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Ignition-status communication
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Power-management module
CAN Communication Problem
The key-off process may depend on communication between several control modules.
A CAN network problem can prevent modules from receiving the required shutdown information.
Possible causes include:
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CAN High wiring problem
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CAN Low wiring problem
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Open circuit
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Short circuit
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Damaged harness
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Corroded connector
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Faulty network termination
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Module communication failure
Faulty Body Control Module
The BCM often plays an important role in ignition-status monitoring and vehicle power management.
A BCM problem may interfere with:
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Key-off detection
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Delayed accessory operation
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Interior lighting
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Door systems
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Network sleep
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Security functions
However, the BCM should not be replaced based on P1002 alone.
Low Battery Voltage
Low system voltage can cause control modules to behave unpredictably.
Possible causes include:
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Weak battery
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Discharged battery
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Loose battery terminal
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Corroded battery connection
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Charging-system problem
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Excessive parasitic draw
A low-voltage condition can sometimes create several unrelated-looking electronic codes.
Charging System Problem
If the alternator or charging system is not maintaining proper voltage, modules may experience unstable operating conditions.
Check:
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Battery voltage
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Charging voltage
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Alternator operation
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Battery terminals
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Ground connections
Poor Ground Connection
A poor ground can create intermittent module behavior.
Possible causes include:
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Corroded chassis ground
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Loose ground strap
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Damaged ground wire
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High-resistance ground connection
Parasitic Electrical Load
An electrical component that remains active after key-off can prevent the vehicle from entering its normal sleep state.
Possible sources include:
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Aftermarket alarm
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Remote starter
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Dash camera
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GPS tracker
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Audio equipment
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USB accessories
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Non-factory lighting
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Telematics equipment
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Faulty door module
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Faulty infotainment system
Aftermarket accessories deserve particular attention when P1002 is accompanied by battery discharge.
Faulty Door or Hood Switch
The vehicle may keep certain systems awake if it incorrectly believes that:
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A door is open
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The hood is open
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The trunk is open
A faulty switch or latch sensor can therefore interfere with the expected shutdown process.
Infotainment System Problem
A radio or infotainment module that fails to shut down can keep part of the network awake.
Possible symptoms include:
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Screen remaining active
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Audio system not turning off correctly
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Battery drain
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Intermittent network activity
Instrument Cluster Problem
A malfunctioning instrument cluster can also potentially prevent normal network sleep.
Telematics or Security Module Problem
Some vehicles keep telematics and security systems active after key-off.
If one of these systems becomes stuck in an active state, it may delay the expected shutdown sequence.
Software or Calibration Problem
P1002 may sometimes result from a control-module software or calibration issue.
A manufacturer may release:
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Software updates
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Technical Service Bulletins
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Revised calibration
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Updated power-management logic
How Is P1002 Diagnosed?
P1002 should be diagnosed as a vehicle power-management and shutdown-sequence problem, not simply as an ignition-key problem.
A useful diagnostic sequence is:
Scan all modules → check battery voltage → check charging system → review freeze-frame data → confirm ignition-off status → monitor key-off timer → determine which module remains active → inspect CAN communication → check aftermarket accessories → measure parasitic draw if necessary → test suspected module → check software updates → repair → verify sleep mode
Step 1: Confirm the Exact Manufacturer Definition
Because P1002 is manufacturer-specific, identify:
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Make
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Model
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Model year
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Engine
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Ignition system
The generic scanner description may be accurate, but the manufacturer may specify:
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Which module monitors the timer
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The expected timer duration
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Which modules must enter sleep mode
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The exact triggering conditions
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Required diagnostic tests
Manufacturer service information should be used whenever possible.
Step 2: Scan All Control Modules
Do not scan only the ECM/PCM.
Scan modules such as:
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BCM
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ECM/PCM
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Instrument cluster
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TCM
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Infotainment module
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Door modules
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Security module
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Telematics module
Look for:
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U-codes
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Low-voltage codes
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Ignition-status codes
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Body-control codes
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Network communication errors
If several modules report communication problems, the underlying fault may be in the vehicle network or power supply.
Step 3: Check Battery Condition
Before diagnosing complicated electronic faults, verify that the battery is healthy.
Check:
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Battery state of charge
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Battery condition
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Battery terminals
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Battery voltage
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Ground connections
A weak battery can create misleading electronic symptoms.
Step 4: Check Charging System
Verify that the charging system is functioning correctly.
Inspect:
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Alternator
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Charging voltage
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Battery connections
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Ground straps
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Charging-system wiring
If system voltage is unstable, resolve the voltage problem before continuing.
Step 5: Review Freeze-Frame Data
If available, review the conditions under which P1002 was recorded.
Look for:
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Ignition status
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Battery voltage
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Engine RPM
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Vehicle speed
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Module status
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Related diagnostic codes
This can help determine whether the fault occurs during normal shutdown or under a specific operating condition.
Step 6: Verify Ignition-Off Status
The control module must correctly recognize that the ignition has been switched off.
Use a scan tool to monitor available data such as:
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Ignition status
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Run/start status
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Accessory status
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Key-off status
If the system still reports an active ignition state after shutdown, investigate the ignition switch, push-button system, BCM, or associated wiring.
Step 7: Monitor the Key-Off Timer
If manufacturer-specific diagnostic equipment provides access to the key-off timer, monitor its operation.
Determine:
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When the timer starts
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Whether it advances
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Whether it stops
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Whether it resets
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Which event prevents completion
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Which module remains active
The exact timer values are manufacturer-specific.
Step 8: Determine Which Module Remains Awake
This can be one of the most important diagnostic steps when battery drain is present.
After the ignition is switched off, monitor network and module activity.
A module that remains active longer than specified may be preventing the vehicle from entering sleep mode.
Potential sources include:
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BCM
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Infotainment
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Door module
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Cluster
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Telematics
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Security module
Step 9: Inspect Ignition Wiring
Inspect the ignition-status circuit for:
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Broken wires
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Chafing
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Corrosion
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Loose connectors
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Heat damage
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Poor electrical connections
For push-button systems, inspect the relevant electronic ignition-status circuits rather than assuming there is a conventional ignition-switch circuit.
Step 10: Check CAN Communication
If communication codes are present, test the CAN network.
Depending on the manufacturer's procedure, this may include checking:
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CAN High
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CAN Low
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Network resistance
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Shorts
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Opens
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Signal integrity
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Module communication
A communication problem can prevent the normal shutdown sequence.
Step 11: Check for Aftermarket Accessories
Inspect for non-factory equipment such as:
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Dash cameras
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Remote starters
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Alarm systems
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GPS trackers
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Audio amplifiers
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USB devices
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LED accessories
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Telematics devices
Poorly installed aftermarket equipment can keep a vehicle network active after key-off.
Step 12: Check Door, Hood, and Trunk Status
Use scan data to verify that the vehicle correctly recognizes:
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Doors closed
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Hood closed
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Trunk closed
A faulty latch sensor may cause the vehicle to keep certain systems active.
Step 13: Measure Parasitic Draw
If the battery becomes discharged while the vehicle is parked, perform a parasitic-draw test.
The vehicle must be allowed to enter its normal sleep mode before interpreting the current reading.
A high current draw after the specified sleep period indicates that a component or module may remain active.
The exact acceptable current varies by vehicle.
Do not diagnose parasitic draw simply from a current measurement taken immediately after switching the ignition off because many vehicles intentionally consume significant power during their normal shutdown period.
Step 14: Isolate the Active Circuit
If excessive parasitic draw is confirmed, the technician can isolate the affected circuit according to the manufacturer's procedure.
Possible methods include:
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Fuse testing
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Module isolation
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Network monitoring
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Current monitoring
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Scan-tool module status
Care must be taken because disconnecting certain modules can wake other systems or create additional faults.
Step 15: Check Module Software
Check manufacturer technical information for:
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Software updates
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Technical Service Bulletins
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Revised calibrations
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Known sleep-mode problems
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Network-management updates
A software update may resolve a key-off timer problem without replacing hardware.
How to Fix P1002
The correct repair depends on the confirmed cause.
Repair the Ignition-Status Circuit
If the ignition-status signal is incorrect, repair the relevant:
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Wiring
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Connector
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Switch
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Relay
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Start/stop button circuit
Replace a Faulty Ignition Switch
If testing confirms an internal ignition-switch failure, replacement may be required.
The switch should be tested before replacement.
Repair the Push-Button Ignition System
For keyless vehicles, repair the component responsible for the incorrect ignition-status information.
This may involve the:
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Start/stop switch
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BCM
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Smart-key system
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Related wiring
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Power-management circuitry
Repair CAN Wiring
If the communication network is responsible, repair:
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Open circuits
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Short circuits
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Damaged CAN wires
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Corroded connectors
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Loose terminals
Repair or Replace the Module That Remains Awake
If a specific module fails to enter sleep mode, it may require:
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Software update
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Reprogramming
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Repair
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Replacement
The module should be identified through testing rather than replaced simply because P1002 is present.
Remove or Correct Aftermarket Equipment
If an aftermarket device is keeping the network awake, it may need to be:
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Rewired
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Correctly powered
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Properly integrated
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Reprogrammed
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Removed
Repair Door, Hood, or Trunk Sensors
If a faulty switch or latch sensor is preventing normal shutdown, repair or replace the affected component.
Repair Battery or Charging Problems
If low voltage contributed to the fault, correct the underlying battery or charging-system problem.
Update Control-Module Software
If the manufacturer has identified a software problem, update the affected module.
Clear the Code and Verify Sleep Mode
After repairs:
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Clear the diagnostic trouble codes.
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Switch the ignition off.
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Lock the vehicle if required by the manufacturer's procedure.
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Allow the vehicle to complete its shutdown sequence.
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Monitor network/module activity.
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Verify that the key-off timer completes normally.
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Check parasitic current if battery drain was a symptom.
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Start the vehicle again.
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Rescan all modules.
P1002 should not return if the shutdown sequence is functioning correctly.
Can You Drive With P1002?
In many cases, a vehicle with P1002 can still be driven.
P1002 generally concerns the vehicle's electronic shutdown or power-management process rather than an immediate mechanical engine problem.
However, the underlying fault can become important if it causes:
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Battery drain
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Repeated low-voltage conditions
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Starting problems
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Multiple communication faults
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Electrical accessories remaining active
If the vehicle repeatedly has a dead battery after being parked, the problem should be diagnosed promptly.
Is P1002 a Serious Code?
P1002 is generally considered a low-to-moderate severity diagnostic code, but the severity depends on the underlying cause.
The code itself does not necessarily indicate engine damage.
A temporary communication or software issue may have little practical effect.
However, a module that remains awake can create a significant parasitic battery drain.
Repeated battery discharge can eventually lead to:
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Premature battery failure
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Starting problems
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Additional low-voltage fault codes
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Electronic system malfunctions
Therefore, P1002 should not be ignored if it repeatedly returns or is accompanied by battery-drain symptoms.
P1002 vs. Ignition Switch Failure
These are not the same thing.
P1002
Indicates that the key-off timer or associated shutdown process is performing too slowly.
Ignition switch failure
Means that testing has confirmed that the physical or electronic ignition switch is not providing the correct signal.
An ignition switch problem can potentially cause P1002, but the code alone does not prove that the switch is defective.
P1002 vs. Battery Drain
P1002 does not automatically mean that the battery is being drained.
However, the two can be related.
For example:
Faulty module → remains awake → key-off timer takes too long → excessive parasitic draw → battery discharge
Alternatively:
Weak battery → unstable module operation → shutdown communication problem → P1002
Therefore, both directions should be considered during diagnosis.
P1002 vs. CAN Communication Problems
A CAN communication fault can potentially interfere with the shutdown sequence.
For example:
Ignition OFF → modules exchange shutdown messages → CAN communication fails → module does not enter sleep mode → key-off timer remains active → P1002
If P1002 appears with U-codes, CAN wiring and module communication should be investigated.
P1002 vs. Low Battery Voltage
Low voltage can sometimes create P1002 indirectly.
A weak battery or charging-system problem may cause control modules to reset or communicate incorrectly.
If P1002 appears together with several low-voltage or communication codes, check the vehicle's power supply before replacing electronic modules.
How to Prevent P1002
Regular electrical and electronic-system maintenance can reduce the likelihood of key-off timer problems.
Recommended practices include:
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Keep the battery properly charged and in good condition.
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Maintain the charging system.
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Keep battery terminals clean and secure.
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Repair damaged wiring promptly.
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Protect connectors from moisture and corrosion.
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Address recurring U-codes.
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Repair ignition-status problems promptly.
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Avoid poorly installed aftermarket electrical accessories.
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Check for battery drain if the vehicle repeatedly struggles to start after sitting.
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Keep control-module software updated when required.
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Do not ignore electrical accessories that remain active after key-off.
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Follow manufacturer procedures when replacing or programming control modules.
Final Thoughts
P1002 Ignition Key-Off Timer Performance Too Slow indicates that the vehicle's control system has detected that the ignition-off shutdown timer is taking longer than expected.
Modern vehicles use a controlled shutdown process after the ignition is switched off. Control modules communicate with each other, save information, complete delayed functions, and eventually enter a low-power sleep state.
P1002 can occur when this process is delayed or does not complete as expected.
The most important point is that P1002 does not automatically mean that the ignition key or ignition switch is defective.
Possible causes include:
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Incorrect ignition-status signal
-
Faulty ignition switch
-
Push-button ignition system problem
-
BCM malfunction
-
Control module failing to enter sleep mode
-
CAN communication problems
-
Damaged wiring
-
Corroded connectors
-
Poor battery voltage
-
Charging-system problems
-
Parasitic electrical loads
-
Faulty infotainment, door, cluster, security, or telematics modules
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Software or calibration problems
-
Aftermarket electrical accessories
Diagnosis should begin by confirming the exact manufacturer-specific definition of P1002 and scanning all vehicle control modules for related codes.
The battery and charging system should be checked first because low voltage can create misleading electronic faults.
The technician should then verify the ignition-off status, monitor the key-off timer when possible, identify which module or circuit is preventing normal sleep mode, inspect CAN communication, and check for aftermarket equipment or excessive parasitic current.
If the ignition-status signal is incorrect, the relevant switch, wiring, relay, or control circuit should be repaired.
If a control module remains awake after key-off, that module should be identified and tested before replacement. Depending on the cause, it may require a software update, reprogramming, repair, or replacement.
After the repair, the vehicle should be allowed to complete its normal shutdown sequence and enter sleep mode. If battery drain was present, parasitic current should be verified after the vehicle reaches its specified sleep state.
A final scan should confirm that the key-off timer completes within the expected time, the vehicle enters normal sleep mode, communication remains stable, and P1002 does not return.
