Powertrain
generic / SAE
P24CD
Reductant Tank Cap Switch Circuit Low
Same as P24CB with the signal shorted 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.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number4 / CD
Possible causes
- Signal shorted 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: easy
- DIY: possible
- Estimated cost: 40–200 €
- Estimated time: 0.3–1 h
- Component: reductant tank cap switch
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012