Powertrain, generic · Transmission

P08AC Clutch Pedal Position Not Learned

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

The engine controller has to know at which pedal position the clutch is fully released or disengaged. GM teaches the fully applied position at the factory and then adapts it over time to clutch wear. P08AC is set when this learned value falls outside a window (LV7 1.4 L: 7–33 %, 2019 Corvette ZR1: 9–36 % of travel) or when the manufacturer's enable counter shows the learn was never completed; 250 ms loop, Type A, MIL after one trip. Before 2018 GM used P080A. After replacing the sensor, pedal parts, clutch or ECM, a relearn with a scan tool is needed; FCA, for example, issued a Renegade bulletin calling for a clutch pedal sensor learn. Circuit faults (P08A9/P08AA) must be cleared first.

Likely causes

Relearn not performed after replacing the sensor, clutch parts or engine control module
Learned position drifted out of the allowed window (worn clutch, wrong pedal stop, air in hydraulics)
Learn procedure aborted, for example by low battery voltage
Faulty or misaligned clutch pedal sensor preventing a valid learn

Symptoms

  • Malfunction indicator lamp on
  • Start-stop, cruise control or automatic parking brake release not working as expected

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–250
Time0.3–1 h

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

Parts involved

clutch pedal position sensor awiring harnessecm

Related codes

P08A8P08A9P08AAP080A

References: gsi.ext.gm.com, gsi.ext.gm.com, static.nhtsa.gov.