P24C5 EGR Cooler Bypass Position Sensor Exceeded Learning Limit Bank 2

P24C5 belongs to engines with a second EGR cooler and bypass flap on bank 2. It reports that the end positions learned by that flap's position sensor fall outside the accepted window, so the controller can no longer trust where the flap really stands. No manufacturer documents P24C5 publicly; GM's diesel engines in the available tables use one bypass valve and only show the bank 1 code P24C4. There the learning runs after key-off with a warm engine and checks the raw voltage at both end stops against fixed bands, which gives a good picture of what the bank 2 test checks. CARB requires position feedback of emission-related actuators to be monitored for rationality. Electrical faults of the same sensor are P2497 to P249B; the bank 1 learning fault is P24C4.

Likely causes

Symptoms

• Malfunction indicator lamp on
• Higher NOx emissions due to poorly controlled EGR cooling

Repair estimate

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

Parts involved

Related codes

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