P208C
Reductant Pump A Control Circuit Low
DEF pump A control line stuck low — short to ground. 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.
Possible causes
- Short to ground high
- Connector pins corroded - high contact resistance low
- Harness chafing through insulation low
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)
Inspection / repair
- Difficulty: medium
- DIY: shop recommended
Pro mode: costs, time and components
Free with the newsletter by Fabian Brose: enter your name and email, confirm by mail – Pro mode is then unlocked on this device for 30 days. The newsletter arrives about every two weeks, unsubscribe at any time. Already subscribed? One click is enough – you will be recognised.
Unlock Pro mode for free