31-01-2025
13 min.
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P2145 Exhaust Gas Recirculation (EGR) Vent Control Circuit High

The P2145 Exhaust Gas Recirculation (EGR) Vent Control Circuit High diagnostic trouble code indicates that the Engine Control Module (ECM/PCM) has detected a voltage level that is higher than expected in the electrical control circuit for the EGR vent control system.

In simple terms, the vehicle's computer is seeing too much voltage in the circuit used to control the EGR vent.

The EGR system reduces certain exhaust emissions by recirculating a controlled amount of exhaust gas back into the engine. The vent control circuit helps manage the operation of the EGR system. If the electrical signal is too high, the ECM may be unable to control the EGR system correctly and can store P2145.

Depending on the vehicle, symptoms may include Check Engine Light illumination, rough idle, hesitation, poor acceleration, reduced engine performance, increased emissions, poor fuel economy, engine stalling, or difficulty maintaining normal engine operation.

The exact design of the EGR vent circuit varies between manufacturers, so diagnosis should always be based on the vehicle's specific wiring diagram and service information.

What Does P2145 Mean?

P2145 means that the ECM/PCM has detected a high electrical signal in the EGR vent control circuit.

The code refers to an electrical circuit problem, not necessarily a mechanically stuck EGR valve.

Possible causes include:

Short to battery voltage
Damaged EGR wiring
Faulty EGR vent control solenoid
Damaged connector
Corroded terminals
Faulty EGR control circuit
Power-supply problem
Incorrect wiring repair
Aftermarket electrical modification
ECM/PCM fault

A dirty or carbon-blocked EGR valve can cause EGR-related problems, but carbon buildup alone does not necessarily explain a circuit-high code such as P2145.

What Is the EGR System?

EGR stands for Exhaust Gas Recirculation.

The EGR system redirects a controlled amount of exhaust gas back into the engine's intake system.

Because exhaust gas contains relatively little oxygen, introducing a measured amount into the combustion process can lower peak combustion temperatures.

This helps reduce the formation of nitrogen oxides (NOx).

Depending on the vehicle, an EGR system may contain:

EGR valve
EGR control solenoid
EGR vent or bypass control
EGR position sensor
Differential pressure sensor
EGR temperature sensor
Vacuum lines
Electrical wiring
ECM/PCM control circuits

Modern EGR systems can be electronically controlled and may contain several valves and sensors.

What Is the EGR Vent Control Circuit?

The EGR vent control circuit is part of the system used to regulate EGR operation.

Depending on the vehicle, the vent-control component may:

Control exhaust-gas flow
Control vacuum
Open or close a vent passage
Manage EGR pressure
Regulate EGR valve operation
Control an electronically operated EGR component

The exact function depends on the vehicle's design.

This is why the code should not be diagnosed simply by replacing the EGR valve.

What Does "Circuit High" Mean?

The word "high" in P2145 generally refers to an electrical signal or voltage that is higher than the ECM expects.

It does not necessarily mean:

Excessive exhaust pressure
Too much EGR flow
High engine temperature
A mechanically open EGR valve

For example, a control wire may be unintentionally connected to battery voltage.

Other possibilities include an internal electrical fault in the EGR vent control component or a problem with the circuit's expected voltage state.

Symptoms of P2145

The symptoms can vary depending on the vehicle and whether the EGR system is stuck active, inactive, or simply electrically malfunctioning.

Check Engine Light

The most common symptom is illumination of the Check Engine Light.

Rough Idle

Incorrect EGR operation can affect combustion stability, especially at idle.

Engine Hesitation

The engine may hesitate during acceleration.

Poor Acceleration

The vehicle may feel slower or less responsive.

Reduced Engine Power

Some vehicles may enter a reduced-power or protective operating mode.

Engine Stalling

If EGR flow becomes excessive or the system operates incorrectly, the engine may stall, particularly at idle.

Poor Fuel Economy

Incorrect combustion conditions can affect fuel consumption.

Increased Emissions

An EGR malfunction can increase emissions and may cause the vehicle to fail an emissions inspection.

Engine Surging

Some vehicles may experience inconsistent engine operation or surging.

Hard Starting

Incorrect EGR operation can sometimes make starting more difficult.

Engine Vibration

Poor combustion control may produce noticeable vibration.

Additional Warning Lights

Depending on the vehicle, other warning indicators may appear if the EGR problem affects engine management.

Common Causes of P2145

Short to Battery Voltage

A short to battery voltage is one of the most important possibilities when diagnosing a circuit-high code.

A damaged wire may contact a positive power source.

Possible causes include:

Melted insulation
Chafed wiring
Incorrect wiring repair
Harness damage
Aftermarket modifications

Damaged EGR Wiring

EGR components are often located in areas exposed to significant engine and exhaust heat.

Wiring can suffer from:

Heat damage
Melting
Chafing
Broken conductors
Oil contamination
Corrosion
Vibration damage

A visual inspection of the wiring is therefore important.

Faulty EGR Vent Control Solenoid

If the vehicle uses an electrically controlled EGR vent solenoid, an internal electrical failure can cause an abnormal circuit signal.

Possible faults include:

Internal short circuit
Failed coil
Incorrect resistance
Internal component failure

The solenoid should be tested according to manufacturer specifications.

Corroded Electrical Connector

Corrosion can alter the electrical characteristics of the circuit.

Look for:

Green or white corrosion
Oxidized terminals
Moisture
Loose pins
Poor terminal tension
Damaged connector housing

Loose Electrical Connection

A poor connection can create intermittent electrical faults.

Potential locations include:

EGR connector
Engine harness
Fuse box
Relay connections
ECM/PCM connectors

Incorrect Wiring Repair

A previous repair may have connected the EGR circuit to the wrong electrical source.

This can cause the ECM to detect a voltage higher than expected.

Faulty Power-Supply Circuit

An incorrect power supply can cause the EGR vent circuit to operate outside its intended voltage range.

Possible causes include:

Incorrect fuse
Wiring fault
Relay problem
Power-distribution fault

Aftermarket Electrical Modifications

Electrical modifications can interfere with EGR circuits.

Potential sources include:

ECU modifications
Performance wiring
Remote-start systems
Engine swaps
Modified engine harnesses
Emissions-system modifications

Carbon Deposits in the EGR System

Carbon buildup can restrict EGR passages or cause an EGR valve to stick.

Possible symptoms include:

Rough idle
Hesitation
Reduced performance
Increased emissions

However, carbon buildup is generally a mechanical EGR-flow problem rather than the direct cause of a circuit-high electrical fault.

It should still be inspected if EGR operation is abnormal.

Faulty EGR Position Sensor

Some EGR systems use a position sensor to tell the ECM where the valve is located.

A faulty sensor can produce abnormal feedback signals.

Possible causes include:

Internal sensor failure
Wiring problems
Connector problems
Incorrect reference voltage

The sensor should be tested according to manufacturer specifications.

ECM/PCM Problem

A control-module problem is possible, but it is generally less common than wiring, connector, solenoid, or power-supply faults.

The ECM/PCM should only be considered after the EGR circuit has been properly tested.

Vehicles Commonly Affected by P2145

P2145 can appear on many OBD-II vehicles equipped with electronically controlled EGR systems.

Examples can include:

Ford F-150
Ford Explorer
Ford Escape
Ford Focus
Ford Transit
Chevrolet Silverado
Chevrolet Tahoe
Chevrolet Suburban
Chevrolet Equinox
GMC Sierra
GMC Yukon
Cadillac Escalade
Dodge Ram
Dodge Charger
Dodge Challenger
Jeep Grand Cherokee
Jeep Wrangler
Chrysler Pacifica
Toyota Tundra
Toyota Tacoma
Nissan Titan
Nissan Pathfinder
Nissan Frontier
Honda Pilot
Honda Accord
BMW 3 Series
BMW 5 Series
Mercedes-Benz E-Class
Volkswagen Passat
Audi A4
Audi A6

This list is not exhaustive.

P2145 can occur on both gasoline and diesel vehicles, depending on the engine-management system and the specific EGR architecture.

Important: The exact EGR vent component and circuit configuration can vary considerably by manufacturer and engine. Vehicle-specific service information should be used to identify the affected circuit.

How Is P2145 Diagnosed?

Proper diagnosis should focus on determining why the EGR vent control circuit voltage is higher than expected.

Scan for Additional Trouble Codes

Start with a complete scan of the vehicle.

Look for:

P2145
Other EGR codes
EGR position sensor codes
EGR flow codes
Intake-system codes
Engine-performance codes
Battery-voltage codes
Communication codes

Additional codes can help identify whether the problem is electrical, mechanical, or part of a broader engine-management issue.

Check Freeze-Frame Data

Review the conditions under which P2145 was stored.

Useful parameters include:

Engine RPM
Vehicle speed
Engine load
Coolant temperature
Battery voltage
Throttle position
EGR command
EGR position

This can help determine when the circuit-high condition occurs.

Inspect the EGR System

Locate the EGR vent control component and inspect it for:

Physical damage
Excessive heat exposure
Carbon deposits
Loose mounting
Damaged vacuum lines
Wiring damage

Identify the Correct EGR Circuit

Use the vehicle-specific wiring diagram to identify:

EGR vent control component
Power supply
Ground
Control wire
Feedback wire
Fuse
Relay
ECM/PCM terminals

Do not assume the wiring configuration is the same across different vehicles.

Check the EGR Fuse

Inspect the fuse associated with the EGR system.

Verify that:

The correct fuse is installed.
The fuse is not damaged.
The fuse socket is not burned.
There is no evidence of previous incorrect repairs.

A circuit-high code is not normally solved simply by replacing a fuse, but the fuse and power supply should still be verified.

Measure EGR Circuit Voltage

Measure the voltage at the appropriate circuit terminals under the manufacturer's specified test conditions.

Compare the measured value with the manufacturer's specification.

If the voltage is higher than expected, trace the circuit toward:

Battery power
Fuse
Relay
Wiring
EGR control component
ECM/PCM

Check for a Short to Battery

With the circuit safely isolated according to manufacturer procedures, check whether the control circuit has an unintended connection to battery voltage.

This is particularly important for a circuit-high code.

Inspect Wiring for Heat Damage

Because EGR components can operate near hot exhaust components, carefully inspect the harness for:

Melted insulation
Brittle wiring
Exposed conductors
Chafing
Burn marks
Improper routing

Inspect EGR Connectors

Check connectors for:

Corrosion
Loose terminals
Bent pins
Water intrusion
Damaged locking tabs
Poor terminal tension

Test the EGR Vent Control Component

Depending on the design, test:

Coil resistance
Power supply
Ground
Control signal
Actuator operation

Compare all measurements with manufacturer specifications.

Do not apply battery voltage directly to an electronically controlled EGR component unless the manufacturer's test procedure specifically allows it.

Check EGR Position Feedback

If the EGR system includes a position sensor, verify that the feedback signal changes correctly as the valve or actuator moves.

An abnormal feedback signal can indicate:

Faulty sensor
Wiring problem
Connector fault
Mechanical actuator problem

Inspect EGR Passages

If electrical tests are normal, inspect the EGR passages for:

Carbon buildup
Restricted passages
Stuck valve
Damaged components

This helps determine whether there is also a mechanical EGR problem.

Check ECM/PCM Power and Grounds

Verify:

Battery power
Ignition power
ECM/PCM grounds
Relevant reference-voltage circuits

Poor power or ground connections can create unusual control-module readings.

Check for Aftermarket Modifications

Inspect the vehicle for modifications involving:

ECU
Engine wiring
EGR system
Engine swap
Performance electronics
Emissions-system modifications

Incorrect modifications can alter the expected EGR circuit voltage.

How to Fix P2145

The correct repair depends on the actual cause of the high-voltage condition.

Repair a Short to Battery

If the EGR control wire is shorted to battery voltage, repair the damaged wiring and restore the correct harness routing.

Repair Damaged EGR Wiring

Replace or repair wiring damaged by:

Exhaust heat
Chafing
Corrosion
Vibration
Oil contamination
Previous repairs

Protect the repaired harness from future heat and mechanical damage.

Repair or Replace EGR Connectors

Replace damaged terminals or connector housings when necessary.

Ensure proper terminal tension and connector locking.

Replace a Faulty EGR Vent Control Solenoid

If testing confirms that the vent control solenoid has an internal electrical fault, replace it with the correct component.

Repair Power-Supply Problems

Correct problems involving:

Fuse
Relay
Power-distribution wiring
Incorrect electrical connections

Clean or Repair the EGR System

If carbon buildup or mechanical sticking is also found, clean or repair the affected EGR components according to manufacturer procedures.

Replace a Faulty EGR Position Sensor

If the position sensor is confirmed defective, replace it and verify the feedback signal afterward.

Correct Aftermarket Wiring

Restore incorrectly modified EGR wiring to the appropriate manufacturer configuration.

Repair or Replace the ECM/PCM

The ECM/PCM should only be considered after the EGR control circuit, wiring, connectors, power supply, actuator, sensors, and grounds have been properly tested.

What Happens If P2145 Is Ignored?

Ignoring P2145 can lead to continued engine and emissions problems.

Possible consequences include:

Increased emissions
Failed emissions inspection
Poor acceleration
Rough idle
Engine hesitation
Engine stalling
Reduced fuel economy
Reduced engine performance
Additional EGR-related trouble codes
Increased engine operating temperatures under some conditions

If the EGR system is operating incorrectly for an extended period, other engine-management problems may develop.

Can You Drive With P2145?

Driving with P2145 may be possible if the engine is running normally, but the problem should not be ignored.

A short trip may be reasonable if:

The engine starts normally.
The engine runs smoothly.
There is no severe hesitation.
The Check Engine Light is not flashing.
There is no significant loss of power.
No other serious warning lights are present.

The vehicle should still be diagnosed as soon as practical.

Avoid driving if you experience:

Severe engine shaking
Repeated stalling
Major loss of power
Severe hesitation
Flashing Check Engine Light
Multiple warning lights

Is P2145 a Serious Code?

P2145 is generally considered a moderate-severity diagnostic trouble code, although the severity can vary depending on the vehicle and the underlying electrical problem.

The code does not necessarily mean that the EGR valve itself has failed.

However, an incorrect EGR control signal can affect:

Engine operation
Emissions
Fuel economy
Combustion control
Engine performance

If the high-voltage condition is caused by a short to battery voltage, the electrical fault should be repaired promptly to prevent damage to other components.

How to Prevent P2145

Regular maintenance can help reduce the likelihood of EGR electrical and mechanical problems.

Recommended practices include:

Inspect EGR wiring during routine maintenance.
Keep wiring away from hot exhaust components.
Repair damaged wiring promptly.
Keep electrical connectors clean and dry.
Maintain proper engine and chassis grounds.
Address charging-system problems promptly.
Inspect EGR components for excessive carbon buildup when appropriate.
Use the correct EGR components.
Avoid poorly designed electrical modifications.
Secure engine harnesses away from moving and hot components.
Inspect wiring after engine replacement or major repairs.
Do not ignore Check Engine Light warnings.

P2145 vs. Related EGR and Circuit Codes

Code	General Description
P2145	EGR Vent Control Circuit High
P2146	Fuel Injector Group "A" Supply Voltage Circuit/Open
P2147	Fuel Injector Group "A" Supply Voltage Circuit Low
P2148	Fuel Injector Group "A" Supply Voltage Circuit High
P2149	Fuel Injector Group "B" Supply Voltage Circuit/Open
P2150	Fuel Injector Group "B" Supply Voltage Circuit Low
P2151	Fuel Injector Group "B" Supply Voltage Circuit High

P2145 is different from the nearby P2146–P2151 injector codes because P2145 concerns the EGR vent control circuit, while those codes concern fuel-injector supply circuits.

Final Thoughts

The P2145 Exhaust Gas Recirculation (EGR) Vent Control Circuit High diagnostic trouble code indicates that the ECM/PCM has detected a higher-than-expected electrical signal in the EGR vent control circuit.

Common causes include:

Short to battery voltage
Damaged EGR wiring
Faulty EGR vent control solenoid
Corroded connectors
Loose electrical terminals
Power-supply problems
Incorrect wiring repairs
Aftermarket electrical modifications
EGR position sensor problems
ECM/PCM faults

The most important point is that P2145 is primarily an electrical circuit diagnosis. A dirty or mechanically stuck EGR valve may cause EGR-related symptoms, but it should not automatically be blamed for a circuit-high fault.

The correct diagnostic process starts with checking additional trouble codes and freeze-frame data, identifying the exact EGR vent control circuit using the vehicle's wiring diagram, measuring circuit voltage, checking for a short to battery, inspecting wiring and connectors, testing the EGR control component and position feedback, and verifying ECM/PCM power and grounds.

P2145 does not automatically mean that the EGR valve needs to be replaced. A damaged wire, shorted control circuit, faulty solenoid, corroded connector, or incorrect wiring repair can produce the same diagnostic trouble code.

Finding the actual source of the high electrical signal is essential for repairing P2145 correctly and restoring proper EGR operation and emissions control.