P202E: Reductant Injection Valve Circuit Range/Performance (Bank 1 Unit 1)

P202E concerns the first DEF dosing valve on bank 1, which in most SCR systems is the only one. The circuit itself is intact, but the valve does not behave as commanded. GM's 6.6 L LML (2014 table) checks what the valve driver was told to do against the actual state of its circuit and sets a Type A code after more than ten mismatches within 80 injections, checked only with the coil between about −7 and 100 °C. In GM's 2018 diesel tables an active stuck-tip fault of the valve also blocks the SCR efficiency test P20EE. Chrysler reflashed the dosing control unit of 2013–2014 Ram 2500 to 5500 with 6.7 L Cummins against needless P202E (bulletin 18-010-14), and Hino traced some cases on 2013 J08 trucks to software misjudging DEF pressure. Real faults are crystal-stuck valves or bad contacts; too little DEF raises NOx.

Bank 1 is the side of the engine with cylinder 1. Inline engines only have this bank.

Symptoms

• Malfunction indicator lamp on
• DEF system warning, possibly countdown to speed limitation
• Possibly additional SCR efficiency codes

Most likely causes

• Dosing valve sticking from urea crystals or a clogged tip
• Dosing or engine control unit software (updates available on some models)
• Corroded valve connector or harness
• DEF pressure at the valve outside the expected range

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the AdBlue/DEF level and quality, and do not add additives or water
2. Compare the reading with other engine data while varying the engine speed.
3. Look for white crystals around the injector and the tank
4. Check connectors and heaters with the scanner
5. Run the dosing test available on your diagnostic tool
6. Replace parts only when the test points to that component

Good to know

• Repair difficulty: medium
• It can trigger limp mode.
• It affects emissions.

What each character of P202E means

• P: Powertrain: engine and transmission
• 2: Generic code: same on every make
• 0: Subsystem depends on the code range
• 2E: Specific fault in that system

Frequently asked questions

Can I keep driving with code P202E?

Deal with it soon. If the instrument cluster shows a countdown, the car may not restart once it reaches zero.

What causes code P202E?

The most common causes are: dosing valve sticking from urea crystals or a clogged tip; dosing or engine control unit software (updates available on some models); corroded valve connector or harness.

Related codes

• P201AReductant Injection Valve Circuit Range/Performance (Bank 2 Unit 1)
• P2047Reductant Injection Valve Circuit/Open (Bank 1 Unit 1)
• P208EReductant Injection Valve Stuck Closed (Bank 1 Unit 1)
• P204FReductant System Performance (Bank 1)
• P20EESCR NOx Catalyst Efficiency Below Threshold (Bank 1)

Sources

• gsi.ext.gm.com: 14OBDG10 Engine Diagnostics
• gsi.ext.gm.com: 18OBDG04 Engine Diagnostics
• static.nhtsa.gov: MC 10136967 9999
• static.nhtsa.gov: MC 10117581 9999

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.