OBD-II code · Powertrain (generic, extended)
P204E Reductant Pressure Sensor Circuit Intermittent/Erratic
DEF pressure sensor signal is unstable or jumps — usually a connector or chafed wire. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
Is it safe to drive with P204E?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyIntermittent connector
- Less likelyConnector with intermittent contact under vibration
- Less likelyHarness routed against vibrating component
Symptoms
- Check engine light or NOx warning on
- AdBlue/DEF level or quality warning
- Possible no-start countdown after ignore period
- Failed emissions inspection (NOx)
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–2 h
- Emissions test
- Likely to fail
- Parts involved
- Reductant Pressure Sensor
Related codes
- P204AReductant Pressure Sensor Circuit
- P204BReductant Pressure Sensor Circuit Range/Performance
- P204CReductant Pressure Sensor Circuit Low
- P204DReductant Pressure Sensor Circuit High
- P204FReductant System Performance
- P2050Reductant Injection Valve Circuit/Open (Bank 2 Unit 1)
- P2051Reductant Injection Valve Circuit Low (Bank 2 Unit 1)
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.