P24AB code meaning
EGR Cooler Coolant Pump Stuck On
Powertrain system Generic code P24xx codes Check engine light
What P24AB means
P24AB is set when the EGR cooler coolant pump keeps running although the controller has switched it off, seen for instance in continued speed feedback or current draw. Causes include a driver stage or relay that stays closed, a short that bypasses the switching side, or pump electronics that ignore the command. For the driver this is less urgent than a pump that will not run, but a constantly running pump drains the battery after shut-off and can slow engine warm-up. Public documentation of this check by a carmaker was not found; it follows from CARB's demand that switched outputs be verified in operation. P24A8 covers the opposite failure, P24A9 a short to ground that may keep the pump running.
P24AB at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairAfter a drive cycle
Symptoms of P24AB
- Pump audible after engine shut-off
- Battery drained after standing
- Malfunction indicator lamp on
Common causes of P24AB
- Most likelyRelay or controller output stage stuck closed
- PossibleShort in the harness bypassing the switched side
- Less likelyPump electronics no longer responding to the command
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
EGR cooler coolant pump
What each part of P24AB means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 4 | Area: auxiliary emission controls (catalytic converter, EGR, EVAP). |
| AB | The exact fault in that area. |
What to do next
- Note P24AB and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P24AB
What does P24AB mean?
P24AB means "EGR Cooler Coolant Pump Stuck On". P24AB is set when the EGR cooler coolant pump keeps running although the controller has switched it off, seen for instance in continued speed feedback or current draw. It is a generic code, so it means the same on every make.
Is it safe to drive with P24AB?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P24AB fail an emissions test?
Yes, it can. P24AB is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P24AB to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P24AB clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.