OBD-II code · Powertrain (generic, extended)
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.
Is it safe to drive with P24CD?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySignal shorted to ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
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
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.3–1 h
- Emissions test
- Likely to fail
- Parts involved
- Reductant Tank Cap Switch
Related codes
- P24CAParticulate Matter Sensor Temperature Circuit Intermittent
- P24CBReductant Tank Cap Switch Circuit
- P24CCReductant Tank Cap Switch Circuit Range or Performance
- P24CEReductant Tank Cap Switch Circuit High
- P24CFReductant Tank Cap Switch Circuit Intermittent or Erratic
- P24D0Particulate Matter Sensor Supply Voltage Circuit Low
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.