P2062 — Reductant/Regeneration Supply Control Circuit/Open #

Note: The wording of this code may vary depending on the vehicle manufacturer (OEM). Always verify the exact description in your vehicle’s technical documentation.

• P2062 – Reductant Supply Control Circuit/Open (GM, Ford, Chrysler, Mercedes-Benz)
• P2062 – Reductant Regeneration Supply Control Circuit/Open (BMW, Volkswagen/Audi, Toyota)
• P2062 – Diesel Exhaust Fluid Supply Control Circuit/Open (Cummins, Nissan, Isuzu)

Overview of DTC P2062 #

DTC P2062 refers to a detected issue within the Reductant Supply Control Circuit or its wiring, usually in vehicles equipped with Selective Catalytic Reduction (SCR) systems. The term “Reductant” most often refers to Diesel Exhaust Fluid (DEF), a solution injected into the exhaust to reduce nitrogen oxide (NOx) emissions. When the Powertrain Control Module (PCM) or Engine Control Module (ECM) senses an open or faulty circuit controlling the supply of reductant, it sets this code. This issue may impact the ability of the emission system to operate properly, potentially leading to higher emissions and triggering the Malfunction Indicator Lamp (MIL or “Check Engine” light). Prompt attention is important, as ongoing problems can cause further emission system damage and, in some cases, performance issues.

Common Symptoms for Fault Code P2062 #

Vehicles with P2062 often display a range of symptoms, although the severity can vary based on the model and the extent of the circuit failure. Watch for:

• Check Engine Light (MIL) illuminated
• Emission system warnings or DEF system warnings on the instrument cluster
• Possible reduction in engine power or “limp” mode, particularly after multiple driving cycles with the fault active
• Increase in NOx emissions (may be detected during emissions testing)
• Difficulty or inability to perform forced DPF regeneration (on some models)

Probable Causes for DTC P2062 #

The most common causes for P2062 relate to issues within the DEF supply circuit or its components. Diagnosing these in order of likelihood can save time:

1. Faulty or disconnected reductant (DEF) supply pump
2. Open or damaged wiring/connectors between the PCM/ECM and the reductant supply pump
3. Failed reductant supply control relay
4. Defective reductant supply module or associated sensors
5. Internal short or open in the PCM/ECM (rare)
6. Poor ground or corroded power connections in the DEF system harness

Step-by-Step Diagnostic for P2062 #

Diagnosing P2062 requires a systematic approach to locate the exact source of the open circuit or control problem. Here’s how a qualified technician or knowledgeable DIYer should proceed:

• Confirm code and check for related DTCs using a professional scan tool. Note any other emission or DEF-related codes present.
• Inspect the DEF/reductant supply pump and wiring harness for obvious damage, corrosion, or disconnections.
• Test the supply pump and control relay operation using scan tool activations or direct power/ground checks. Listen for pump noises or use a meter to measure current draw.
• Check for voltage and ground at the supply pump connector with the circuit energized. Compare against OEM wiring diagrams.
• Test circuit continuity between the PCM/ECM and supply pump using a multimeter; look for open circuits or high resistance.
• Inspect and test the control module (if separate from the PCM/ECM) for internal faults or communication errors.
• Clear codes and run a functional test after any repair to confirm resolution and system readiness.

Possible Repairs for P2062 #

Depending on the root cause, repairs for P2062 may be straightforward or require component replacement. The most effective approach is to address the issue identified during diagnosis:

• Repair or replace damaged wiring/connectors in the reductant supply circuit
• Replace the DEF/reductant supply pump if it fails activation or electrical testing
• Replace the control relay if it does not provide correct switching or power output
• Clean or repair corroded ground/power connections
• Replace the reductant supply module if found defective
• In rare cases, reprogram or replace the PCM/ECM if an internal fault is confirmed

Is It Safe to Drive with Code P2062? #

Limited — While driving may still be possible with the P2062 code present, it is not recommended for extended periods. The vehicle’s emission control system may not function correctly, potentially leading to increased pollution, failed emissions tests, or further system degradation. Some vehicles will enter a “limp” mode after a given number of drive cycles, which can restrict power and speed. Prompt diagnosis and repair is strongly advised.

Vehicles Most Commonly Affected by P2062 #

This code is most prevalent in diesel vehicles equipped with SCR (Selective Catalytic Reduction) systems. Manufacturers and models with higher occurrence include:

• Chevrolet Silverado/GMC Sierra Duramax
• Ford Super Duty (F-250, F-350) Power Stroke
• RAM 2500/3500 Cummins
• Mercedes-Benz Sprinter
• Volkswagen/Audi TDI models
• BMW diesel sedans and SUVs
• Toyota Land Cruiser/Prado diesel (selected markets)
• Nissan Titan XD Cummins

Common Mistakes & Best Practices for P2062 #

Misdiagnosis and improper repair attempts can lead to wasted time and recurring problems. To avoid common pitfalls, keep these tips in mind:

• Do not replace the DEF pump or module without first verifying wiring and power/ground integrity. Open circuits are often caused by damaged harnesses, not failed components.
• Always use OEM wiring diagrams for accurate circuit tracing and testing.
• Check for Technical Service Bulletins (TSBs) or recalls related to the DEF system for your specific vehicle.
• After repairs, always clear codes and perform a readiness drive cycle to confirm resolution.
• Do not ignore warning lights or continue driving indefinitely, as SCR system issues may eventually trigger severe limp modes or legal compliance issues.

Quick FAQ for P2062 #

Still have questions? Here are answers to the most common concerns:

• Q: Can low DEF fluid level cause P2062?
  A: No—P2062 specifically refers to an electrical/circuit problem, not a fluid level issue. However, a failed supply pump that does not run may also prevent fluid from reaching the system, triggering level or flow warnings separately.
• Q: Will clearing the code fix the problem?
  A: Clearing the code will turn off the warning light temporarily, but if the root cause is not addressed, the code will return as soon as the system detects the fault again.
• Q: Is this a DIY repair?
  A: Basic inspections (like checking for visible wiring damage or loose connectors) are DIY-friendly, but deeper diagnostics or component replacements often require advanced tools and technical knowledge. When in doubt, consult a professional technician.