P24F2
EGR Temperature/Charge Air Cooler Temperature Correlation
After a long key-off soak both the EGR temperature sensor and the charge-air cooler outlet temperature sensor must read approximately the same ambient temperature. The ECM compares them and detects an implausible delta. One of the sensors drifts, is wired wrong, or is exposed to a heat source the model does not know about.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Check engine light on
- Pinging or knocking under load
- Power loss and hesitation
- Possible rough idle
- Failed emissions inspection (NOx)
Common causes
Ordered by how often each turns out to be the cause.
- One sensor drifting outside toleranceCommon
- Residual heat in the charge-air cooler after a hot soakPossible
Parts involved
- EGR Temperature Sensor
- Cac Outlet Temperature Sensor
P24F2 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.