P24A6 code meaning
EGR Cooler Bypass Control Stuck/Open (Bank 2)
Powertrain system Generic code P24xx codes Check engine light
What P24A6 means
P24A6 is reserved for a mechanically stuck cooler bypass on bank 2. No manufacturer documents it publicly; the Ford and GM diesel summaries that describe the stuck test all apply it to a single bank and use P24A5. Their methods show how a second bank would be checked: either the measured flap position is compared with where it should rest, or the flap is switched and the gas temperature after the cooler must respond, as CARB's EGR cooler requirements expect. On a twin-cooler V engine a stuck bank 2 flap leaves that side either always bypassing, raising NOx, or always cooling, which slows warm-up and adds soot. Carbon build-up and a failing actuator are the likely reasons. Electrical faults on this bank are P248E, P2490 and P2491; the drift check is P248F.
P24A6 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyHard
- Typical labor1 to 6 hours
- Clears after repairAfter a drive cycle
Symptoms of P24A6
- Check engine light on
- Uneven exhaust temperatures between the two banks
Common causes of P24A6
- Most likelyBank 2 flap seized by deposits
- PossibleBank 2 actuator or linkage failed
- Less likelyMissing vacuum on a pneumatically switched bypass
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
EGR cooler bypass valve b2
What each part of P24A6 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). |
| A6 | The exact fault in that area. |
What to do next
- Note P24A6 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 P24A6
What does P24A6 mean?
P24A6 means "EGR Cooler Bypass Control Stuck/Open (Bank 2)". P24A6 is reserved for a mechanically stuck cooler bypass on bank 2. It is a generic code, so it means the same on every make.
Is it safe to drive with P24A6?
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 P24A6 fail an emissions test?
Yes, it can. P24A6 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 P24A6 to fix?
Difficulty: hard. A typical repair takes 1 to 6 hours of work. This is a job for a workshop.
Will P24A6 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.