P2062 Reductant / Regeneration Supply Control Circuit Open

P2062 Reductant / Regeneration Supply Control Circuit Open is a generic OBD-II diagnostic trouble code indicating that the vehicle's Engine Control Module (ECM/PCM) or aftertreatment control system has detected an open electrical circuit in a reductant or regeneration supply control circuit.

In simple terms, the vehicle's computer is not detecting the expected electrical connection in a circuit used to control or supply a reductant or regeneration-related component.

On many modern diesel vehicles, this can involve the Selective Catalytic Reduction (SCR) system and its Diesel Exhaust Fluid (DEF/AdBlue) supply components. Depending on the manufacturer and engine configuration, however, P2062 may refer to a specific reductant pump, supply valve, heater, regeneration-related component, or associated wiring.

An "open circuit" generally means that electrical current cannot flow through the intended circuit because the electrical path has been interrupted.

Possible causes include:

• Broken wire

• Disconnected connector

• Loose terminal

• Corroded connector

• Failed reductant pump

• Failed supply-control valve

• Failed reductant heater

• Internal wiring fault

• Blown fuse

• Faulty relay

• Damaged reductant tank module

• Poor ground connection

• Failed control-module driver

• Incorrect component installation

• Wiring damaged by exhaust heat

• Internal component open circuit

P2062 is therefore primarily an electrical circuit diagnosis. The reductant component should not automatically be replaced before the wiring and circuit are tested.

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What Does P2062 Mean?

The code description can be divided into several parts.

Reductant

A reductant is a substance used by an emissions-control system to reduce harmful exhaust emissions.

In many diesel vehicles, the reductant is Diesel Exhaust Fluid (DEF), known as AdBlue in many European markets.

DEF is injected into the exhaust upstream of the SCR catalyst. It helps the SCR system chemically convert NOx into primarily nitrogen and water.

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Regeneration

Regeneration refers to the process used to remove accumulated soot from a Diesel Particulate Filter (DPF).

During regeneration, exhaust temperatures are increased so that trapped particulate matter can be oxidized.

Depending on the vehicle, regeneration can involve:

• Additional fuel injection

• Exhaust heaters

• Regeneration injectors

• Air management

• Temperature control

• Other supply components

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Supply Control Circuit

This is the electrical circuit used to control the applicable reductant or regeneration supply component.

It may include:

• Battery power

• Ground

• Control wire

• Pump driver

• Valve driver

• Heater circuit

• Feedback circuit

• Control module

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Open

"Open" means that the control module detects an interrupted electrical path or a circuit condition consistent with no current flow.

An open circuit can occur because of:

• Broken wire

• Disconnected connector

• Failed component

• Corroded terminal

• Blown fuse

• Internal circuit failure

The exact electrical configuration varies by vehicle.

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How Does the Reductant System Work?

A typical SCR/DEF system works as follows:

1. DEF is stored in a dedicated tank.

2. The control system monitors DEF level and temperature.

3. A reductant pump draws fluid from the tank.

4. The pump creates the required supply pressure.

5. DEF travels through the supply line.

6. A dosing system controls the required amount.

7. The DEF injector sprays the fluid into the exhaust.

8. DEF is converted into ammonia-containing compounds.

9. The SCR catalyst uses these compounds to reduce NOx.

10. NOx sensors monitor the system's performance.

11. The control system adjusts reductant dosing according to operating conditions.

If the electrical circuit controlling a supply component is open, the control system may be unable to operate that component correctly, resulting in P2062.

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How Does DPF Regeneration Work?

The DPF traps soot produced during diesel combustion.

As soot accumulates, the vehicle must periodically regenerate the filter.

During regeneration:

1. Soot loading is calculated or estimated.

2. Engine and exhaust conditions are monitored.

3. Exhaust temperature is raised.

4. Accumulated soot is oxidized.

5. DPF restriction is reduced.

6. Normal operation resumes.

Depending on the vehicle, a fuel supply component, heater, or other regeneration-related component may be involved.

Because the exact component assigned to P2062 is manufacturer-specific, the vehicle's wiring diagram and service information should be consulted.

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Symptoms of P2062

Check Engine Light

The Check Engine Light is a common symptom of P2062.

The code may be stored as soon as the control module detects that the monitored circuit is electrically open.

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DEF/AdBlue Warning

SCR-equipped vehicles may display an emissions-system or reductant warning.

Possible messages include:

• Check DEF

• AdBlue system fault

• DEF system malfunction

• Exhaust fluid system fault

• Reductant system fault

The exact message depends on the manufacturer.

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Reduced Engine Power

Some diesel vehicles can reduce engine torque when an important aftertreatment fault is detected.

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Vehicle Speed Limitation

Certain SCR-equipped vehicles can eventually impose a speed limitation if a reductant-system fault remains unresolved.

The exact strategy varies between manufacturers.

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DPF Regeneration Problems

If the open circuit is associated with a regeneration supply component, the vehicle may be unable to perform regeneration correctly.

Possible results include:

• Increasing soot load

• More frequent regeneration attempts

• DPF restriction

• Reduced engine performance

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Increased Exhaust Emissions

If reductant dosing or regeneration is disabled, emissions can increase.

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Increased Fuel Consumption

Repeated failed regeneration attempts can increase fuel consumption.

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Poor Engine Performance

Depending on the affected system, symptoms may include:

• Reduced acceleration

• Hesitation

• Torque limitation

• Poor throttle response

• Reduced engine power

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Warning Messages

The instrument cluster may display an emissions, DPF, or DEF warning.

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No Noticeable Symptoms

P2062 can initially occur without obvious drivability problems.

The vehicle may continue to operate normally while the emissions system monitors the fault.

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Common Causes of P2062

Broken Wiring

A broken wire is one of the most direct causes of an open-circuit code.

Aftertreatment wiring is exposed to:

• Heat

• Vibration

• Water

• Road debris

• Salt

• Chemical contamination

A conductor can break even if the insulation appears intact.

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Disconnected Connector

A connector that has not been fully seated can interrupt the circuit.

This is particularly important after repairs involving:

• DEF tank

• Reductant pump

• Dosing module

• DPF

• SCR system

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Corroded Connector

Moisture or contamination can corrode electrical terminals.

Possible signs include:

• Green corrosion

• White deposits

• Moisture

• Discolored terminals

• Damaged connector seals

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Loose Terminal

A terminal can lose its contact tension and intermittently or completely disconnect the circuit.

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Failed Reductant Pump

The pump may develop an internal open circuit.

Possible causes include:

• Broken motor winding

• Internal electrical failure

• Damaged internal connection

• Failed pump electronics

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Failed Reductant Control Valve

A supply-control valve can develop an open coil or internal electrical fault.

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Failed Reductant Heater

A heater element can fail open.

The heater may show no electrical continuity even though the wiring is intact.

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Blown Fuse

A blown fuse can interrupt the power supply to the affected component.

However, the reason the fuse failed should also be investigated.

A replacement fuse should not simply be installed repeatedly if it blows again.

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Faulty Relay

A failed relay can prevent power from reaching the relevant reductant or regeneration component.

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Poor Ground

An open or high-resistance ground can prevent the circuit from operating correctly.

Depending on the circuit design, the control module may interpret the condition as an open circuit.

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Internal Reductant Tank Module Fault

Some vehicles integrate:

• Pump

• Heater

• Level sensor

• Temperature sensor

• Electronics

into one reductant tank module.

An internal circuit failure can therefore cause P2062.

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Regeneration Supply Component Failure

If P2062 is assigned to a regeneration-related supply component, an internal open circuit in that component can trigger the code.

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Exhaust Heat Damage

Wiring near the DPF, SCR catalyst, turbocharger, or exhaust pipes can become overheated.

Melted insulation or damaged conductors can create an open circuit.

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Incorrect Component Installation

If a pump, heater, valve, or tank module has recently been replaced, verify that:

• The correct component was installed.

• The connector is fully seated.

• The wiring is correctly routed.

• Ground connections are secure.

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Incorrect Replacement Component

An incompatible component may have different electrical characteristics and can cause circuit faults.

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Failed Control Module Driver

The control module may contain a transistor or driver circuit responsible for controlling the component.

If that driver fails, the circuit may not operate correctly.

Control-module failure should generally be considered only after the wiring and component have been verified.

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Software or Calibration Problem

A software or calibration issue can occasionally result in an incorrect circuit fault determination.

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Contaminated or Incorrect DEF

Incorrect or contaminated DEF can cause SCR-related fault codes.

However, contamination does not normally explain an electrical open circuit by itself. P2062 should first be diagnosed electrically.

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Frozen DEF

DEF can freeze in sufficiently cold conditions.

Modern systems are designed to manage freezing and thawing, but a heater problem can prevent normal operation.

A frozen tank alone should not be treated as proof of an open electrical circuit.

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Vehicles Commonly Affected by P2062

P2062 can occur on diesel vehicles equipped with reductant or regeneration-related aftertreatment systems.

Examples may include:

• Ford F-250 Super Duty

• Ford F-350 Super Duty

• Ford F-450 Super Duty

• Ford Transit Diesel

• Chevrolet Silverado Duramax

• Chevrolet Express Diesel

• GMC Sierra Duramax

• GMC Savana Diesel

• Ram 2500

• Ram 3500

• Jeep Grand Cherokee Diesel

• Jeep Wrangler Diesel

• Mercedes-Benz Sprinter

• Mercedes-Benz E-Class Diesel

• Volkswagen Touareg TDI

• Volkswagen Transporter

• Audi Q7 TDI

• BMW X5 Diesel

• BMW X6 Diesel

• Peugeot Boxer Diesel

• Citroën Jumper

• Fiat Ducato Diesel

• Iveco Daily

• Renault Master

• Opel Movano

This list is not exhaustive.

P2062 is a generic OBD-II code, and the exact component represented by the reductant/regeneration supply control circuit depends on the vehicle manufacturer.

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How Is P2062 Diagnosed?

P2062 should be diagnosed by tracing the complete electrical path between the control module and the affected reductant or regeneration supply component.

The goal is to determine where the electrical path is interrupted.

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Step 1: Scan for Additional Trouble Codes

Use a suitable diagnostic scan tool to retrieve all stored and pending codes.

Pay particular attention to codes involving:

• Reductant system

• DEF/AdBlue

• Reductant pump

• Reductant heater

• Dosing system

• NOx sensors

• DPF

• Regeneration

• Aftertreatment module

• Power supply

• Ground

• Communication

If several components lose electrical operation simultaneously, investigate a shared power or ground supply.

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Step 2: Check Freeze-Frame Data

Record the conditions present when P2062 was stored.

Useful parameters may include:

• Engine RPM

• Vehicle speed

• Battery voltage

• Engine temperature

• Exhaust temperature

• DEF temperature

• Reductant pressure

• Regeneration status

• Dosing status

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Step 3: Identify the Exact Circuit

Use the manufacturer's wiring diagram to determine exactly which component is monitored by P2062.

Do not assume it always refers to the DEF pump.

Depending on the vehicle, it can involve a:

• Pump

• Valve

• Heater

• Supply component

• Regeneration component

• Tank module

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Step 4: Inspect Fuses and Relays

Check the fuses and relays supplying the affected component.

A blown fuse should be investigated rather than repeatedly replaced.

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Step 5: Inspect the Wiring

Follow the harness from the component toward the control module.

Look for:

• Broken wires

• Chafing

• Melted insulation

• Corrosion

• Pinched harness sections

• Poor routing

• Previous repairs

Pay particular attention to areas close to the exhaust system.

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Step 6: Inspect Connectors

Check all relevant connectors for:

• Disconnection

• Corrosion

• Bent pins

• Loose terminals

• Damaged locking mechanisms

• Moisture

• Damaged seals

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Step 7: Perform a Continuity Test

With the circuit safely isolated according to the manufacturer's procedure, test continuity between the appropriate circuit terminals.

A healthy circuit should have continuity within the manufacturer's specified limits.

An infinite resistance reading can indicate an open circuit.

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Step 8: Check for a Broken Wire

If continuity is missing, divide the circuit into sections and test each section.

This helps identify the exact location of the open.

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Step 9: Check Voltage at the Component

Verify whether the affected component receives the required power supply.

If power is absent, trace the circuit backward through:

• Fuse

• Relay

• Wiring

• Connector

• Control module

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Step 10: Check Ground

Verify the component's ground connection.

Perform a voltage-drop test where appropriate.

A ground that appears connected visually can still have excessive resistance.

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Step 11: Test the Component

If the wiring and power supply are correct, test the affected component.

Depending on the component, check:

• Resistance

• Continuity

• Current draw

• Actuation

• Feedback signal

Compare measurements with the manufacturer's specifications.

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Step 12: Use an Active Test

If supported by the diagnostic tool, command the component:

• Reductant pump

• Supply valve

• Heater

• Regeneration component

Monitor its electrical response.

A component that does not respond despite having correct power and ground may have an internal failure.

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Step 13: Inspect the Reductant Tank Module

If the vehicle uses an integrated reductant tank module, inspect the module and its internal electrical circuits.

A fault inside the module may require module replacement.

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Step 14: Check Regeneration Operation

If the code is related to regeneration, inspect:

• DPF soot load

• Exhaust temperature

• Differential pressure

• Regeneration history

• Regeneration commands

• Regeneration supply component

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Step 15: Inspect Exhaust Heat Damage

Inspect wiring around:

• DPF

• SCR catalyst

• Exhaust pipes

• Turbocharger

• Regeneration components

Heat-damaged wiring is a common reason to inspect this area carefully.

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Step 16: Check Control Module Output

If the wiring and component are confirmed good, check the control module's output or driver circuit.

Depending on the system, an oscilloscope may be required.

Do not replace the control module based only on the presence of P2062.

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Step 17: Check Manufacturer Technical Information

Look for:

• Technical Service Bulletins

• Known wiring faults

• DEF pump problems

• Reductant heater failures

• Tank module issues

• Regeneration-system problems

• Software updates

• Updated components

• Calibration procedures

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How to Fix P2062

The correct repair depends on where the electrical circuit is open.

Repair a Broken Wire

Replace or correctly repair the damaged section.

The repaired wiring should be properly insulated, secured, and protected from heat and abrasion.

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Repair or Replace the Connector

If a connector is damaged, corroded, or has loose terminals, repair or replace the affected terminals or connector.

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Replace a Blown Fuse

Replace the fuse with the correct rating after determining why it failed.

Do not install a higher-rated fuse.

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Replace a Faulty Relay

If the relay does not supply power correctly, replace it with the correct specification.

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Repair the Ground Circuit

Repair an open or high-resistance ground connection.

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Repair Exhaust Heat Damage

If exhaust heat has damaged the harness:

• Replace damaged wiring.

• Restore heat shielding.

• Secure the harness away from hot components.

• Follow the manufacturer's routing requirements.

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Replace the Reductant Pump

If the pump has an internal open circuit or fails the manufacturer's electrical and functional tests, replace the appropriate pump or module.

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Replace the Reductant Control Valve

If the valve coil or internal circuit is open, replace the valve.

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Replace the Reductant Heater

If the heater element is open and outside specification, replace the heater or applicable module.

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Replace the Reductant Tank Module

If the pump, heater, or electronics are integrated into the reductant tank module and the module has an internal open circuit, the module may need replacement.

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Repair Regeneration Supply Components

If P2062 is associated with a regeneration-related supply component, repair or replace that component according to manufacturer procedures.

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Repair the Control Module

If testing proves that the control module's driver circuit is defective, repair or replace the module as specified.

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Update Control Module Software

If a manufacturer software update addresses P2062, reprogram the applicable module.

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Perform Required Calibration

After replacing a reductant or aftertreatment component, the vehicle may require:

• Reductant pump initialization

• DEF system reset

• Heater calibration

• Dosing-system calibration

• Aftertreatment module programming

• Regeneration procedure

The exact procedure is vehicle-specific.

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Clear the Code and Verify the Repair

After completing the repair:

1. Clear P2062.

2. Run the applicable system self-test.

3. Monitor the affected circuit.

4. Confirm power, ground, and continuity.

5. Activate the component if supported.

6. Verify reductant dosing or regeneration operation.

7. Test-drive the vehicle.

8. Rescan for stored and pending codes.

P2062 should not be considered repaired simply because the code has been erased. The electrical circuit must be confirmed to operate correctly.

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What Happens If P2062 Is Ignored?

The consequences depend on which component is affected.

Possible consequences include:

• Check Engine Light

• DEF/AdBlue warning

• Reduced engine power

• Vehicle speed limitation

• Failed DPF regeneration

• Increasing soot loading

• Increased emissions

• Increased fuel consumption

• Additional aftertreatment fault codes

• Possible restart restrictions on some SCR-equipped vehicles

If P2062 prevents the reductant supply system from operating, SCR emissions control may become unavailable.

If it affects a regeneration supply component, DPF soot accumulation can become progressively worse.

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Can You Drive With P2062?

Short-term driving may be possible if the vehicle starts and runs normally, but P2062 should be diagnosed as soon as possible.

If the vehicle displays a DEF/AdBlue warning or an emissions-system countdown, do not delay the repair.

Continued driving with an unresolved aftertreatment circuit fault can potentially lead to:

• Reduced power

• Speed restrictions

• Failed regeneration

• DPF restriction

• SCR system faults

• Restart restrictions on some vehicles

If the vehicle has severe power loss, repeated regeneration failures, or multiple emissions warnings, it should be inspected promptly.

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Is P2062 a Serious Code?

P2062 is generally considered a moderate-to-high severity emissions-system fault.

The code specifically indicates an open circuit, meaning that an electrical path needed by the reductant or regeneration supply system is interrupted.

While the vehicle may initially continue to operate normally, failure of the affected component can eventually interfere with:

• SCR operation

• DEF dosing

• DPF regeneration

• Emissions control

• Engine power management

The seriousness therefore depends on the exact component and the manufacturer's fail-safe strategy.

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P2062 vs. P2063 and P2064

These three codes describe different electrical conditions in the same general reductant/regeneration supply control circuit family.

Code	General Meaning
P2062	Reductant/Regeneration Supply Control Circuit Open
P2063	Reductant/Regeneration Supply Control Circuit Low
P2064	Reductant/Regeneration Supply Control Circuit High

P2062 — Open

The electrical path is interrupted or the control module detects a condition consistent with an open circuit.

Typical diagnostic areas:

• Broken wire

• Disconnected connector

• Blown fuse

• Failed component

• Loose terminal

• Internal open circuit

P2063 — Low

The circuit voltage or feedback is below the expected range.

Typical diagnostic areas:

• Short to ground

• Low supply voltage

• High-resistance connection

• Poor ground

• Shorted component

P2064 — High

The circuit voltage or feedback is above the expected range.

Typical diagnostic areas:

• Short to battery voltage

• Open circuit in certain circuit designs

• Incorrect resistance

• Failed component

• Control-circuit problem

The distinction helps determine which electrical tests should be performed first.

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How to Prevent P2062

Not every open-circuit fault can be prevented, but proper maintenance can reduce the likelihood of wiring and aftertreatment problems.

Recommended practices include:

• Keep reductant-system wiring properly secured.

• Repair damaged wiring promptly.

• Protect wiring from exhaust heat.

• Keep electrical connectors sealed and clean.

• Address DEF/AdBlue warning messages promptly.

• Use the correct DEF/AdBlue specification.

• Maintain the vehicle's battery and charging system.

• Avoid unnecessary modifications to aftertreatment wiring.

• Use the correct replacement pump, heater, valve, and tank components.

• Follow manufacturer procedures after aftertreatment repairs.

• Do not ignore recurring DPF regeneration problems.

• Maintain the vehicle according to manufacturer recommendations.

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Final Thoughts

P2062 Reductant / Regeneration Supply Control Circuit Open indicates that the vehicle's control system has detected an open electrical circuit in a reductant or regeneration supply control system.

The most important causes include:

• Broken wiring

• Disconnected connector

• Corroded terminal

• Loose electrical connection

• Blown fuse

• Failed relay

• Poor ground

• Faulty reductant pump

• Failed supply-control valve

• Open reductant heater

• Internal reductant tank module failure

• Regeneration supply component failure

• Exhaust heat damage

• Control-module driver failure

• Incorrect component installation

The key point is that P2062 does not automatically mean the DEF pump needs to be replaced.

Because the code specifically identifies an open circuit, diagnosis should begin with the electrical path. The relevant fuse, relay, power supply, ground, wiring, connectors, and component continuity should be checked according to the vehicle manufacturer's wiring diagram and specifications.

If the circuit is open because of a broken wire or disconnected connector, the repair may be relatively straightforward. If the open circuit is internal to a reductant pump, heater, valve, or integrated tank module, that component may require replacement.

If P2062 affects an SCR/DEF supply system, ignoring the fault can eventually result in DEF warnings, reduced engine power, vehicle speed restrictions, increased emissions, and possible restart restrictions on some vehicles. If it affects a regeneration-related component, continued operation can allow DPF soot loading to increase.

The correct repair is to locate the exact point where the circuit is interrupted, repair or replace the affected component, perform any required calibration or system reset, clear the code, and verify that the reductant or regeneration system operates correctly without P2062 returning.