Faulty reductant injection valve with a stuck or restricted pintle; Damaged or corroded wiring harness and connector at the valve; Open or shorted circuit in the valve solenoid coil; Poor electrical connection at the powertrain control module; Clogged or crystallized diesel exhaust fluid injector nozzle; Failed reductant pump or pressure sensor causing abnormal valve operation; Software calibration issue in the powertrain control module

DTC codes / P20xx · Fuel and air metering and auxiliary emission controls / P202E

P202EReductant Injection Valve Circuit Range/Performance (Bank 1 Unit 1)

P202E indicates that the powertrain control module has detected an out-of-range condition in the reductant injection valve circuit for bank 1 unit 1, which is the valve that meters diesel exhaust fluid into the exhaust stream. The computer monitors the circuit for expected voltage or current behavior and flags the code when the signal falls outside the programmed range or fails a performance check.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering and auxiliary emission controls

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
Reduced engine power or limp mode triggered by the powertrain control module
A noticeable increase in diesel exhaust fluid consumption
Rough running or misfire-like symptoms if the valve sticks open and over-injects
Exhaust aftertreatment-related messages on the driver information display
A sulfur or ammonia odor from the exhaust in severe cases

Common causes, most likely first

Faulty reductant injection valve with a stuck or restricted pintle
Damaged or corroded wiring harness and connector at the valve
Open or shorted circuit in the valve solenoid coil
Poor electrical connection at the powertrain control module
Clogged or crystallized diesel exhaust fluid injector nozzle
Failed reductant pump or pressure sensor causing abnormal valve operation
Software calibration issue in the powertrain control module

How to diagnose and fix it

Verify battery voltage and inspect the reductant injection valve connector for corrosion or damage
Check the valve circuit for opens, shorts, and resistance with a digital multimeter
Test the reductant injection valve with a bidirectional scan tool to confirm it responds to commands
Inspect the diesel exhaust fluid injector nozzle for crystallization or blockage and clean if necessary
Check reductant pump pressure and verify the pressure sensor reading matches specifications
Replace the reductant injection valve if electrical and mechanical checks fail
Reprogram the powertrain control module with the latest calibration if no hardware fault is found

What the P202E code does not always mean

A P202E code often sets because of a poor connection at the valve connector rather than a failed valve, so always perform a wiggle test and terminal tension check before condemning the part.
Crystallized diesel exhaust fluid at the injector nozzle can mimic a failed valve by restricting flow, and cleaning the nozzle often resolves the code without replacement.
Low diesel exhaust fluid quality or contamination can cause the valve to stick and set this code, so verify fluid condition and concentration before electrical diagnosis.
The powertrain control module may set P202E as a result of a failing reductant pump that cannot maintain pressure, so always check pump performance and pressure sensor readings.
After replacing the reductant injection valve, a scan tool relearn or adaptation reset is often required to prevent the code from returning immediately.

Can I keep driving with P202E?

You can usually drive the vehicle short distances to a repair shop, but avoid heavy loads and long trips because the powertrain control module may derate engine power or limit vehicle speed. Continued driving with an active fault can increase diesel exhaust fluid consumption and may lead to more extensive aftertreatment damage.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.