P24A6 EGR Cooler Bypass Control Stuck/Open (Bank 2)

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.

Likely causes

Symptoms

• Check engine light on
• Uneven exhaust temperatures between the two banks

Repair estimate

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

Related codes

References: law.cornell.edu, fordservicecontent.com, gsi.ext.gm.com.