OBD-II code · Powertrain (generic, extended)
P24AC EGR Cooler Coolant Pump Feedback Circuit Low
The feedback line that confirms pump speed reads below the plausible range - either pump not turning or feedback line shorted to ground.
Is it safe to drive with P24AC?
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 ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
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.