OBD-II code · Powertrain (generic, extended)
P24CB Reductant Tank Cap Switch Circuit
A general circuit fault on the AdBlue tank cap switch - reports whether the cap is properly closed.
Is it safe to drive with P24CB?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOpen in switch or wiring
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
- P24C8Particulate Matter Sensor Temperature Circuit Low
- P24C9Particulate Matter Sensor Temperature Circuit High
- P24CAParticulate Matter Sensor Temperature Circuit Intermittent
- P24CCReductant Tank Cap Switch Circuit Range or Performance
- P24CDReductant Tank Cap Switch Circuit Low
- P24CEReductant Tank Cap Switch Circuit High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.