OBD-II code · Powertrain (generic, extended)
P24AD EGR Cooler Coolant Pump Feedback Circuit High
Same as P24AC with the feedback line shorted to supply. EGR mixes inert exhaust into intake to lower combustion peak temperature — too little raises NOx, too much causes misfires and rough running.
Is it safe to drive with P24AD?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyFeedback line shorted to supply
- Less likelyConnector pins corroded - high contact resistance
- Less likelySupply wire pinched against B+ source
Symptoms
- Check engine light on
- Pinging or knocking under load
- Power loss and hesitation
- Possible rough idle
- Failed emissions inspection (NOx)
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 1–3 h
- Emissions test
- Likely to fail
- Parts involved
- Egr Cooler Coolant Pump
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.