Powertrain, generic · Transmission

P08A9 Clutch Pedal Position Sensor A Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

The sensor is designed with dead bands at both ends, so a signal near 0 V can only come from a fault. GM sets P08A9 when the signal stays below 4 % of the 5 V reference (low voltage or open circuit) for 400 of 500 samples taken every 12.5 ms, with the engine not cranking and system voltage above 9 V (10 V in some 2018 tables); Type A, MIL after one trip. GM used P0807 for this before 2018 and lists P08A9 for the LV7, the 2019 Corvette ZR1 and its 2018 OBDG04 engines. Ford's 2020–23 gasoline summary uses P08A9 for cars with dual PWM pedal sensors or a single analog sensor plus switches, detected in under a second. The high-side counterpart is P08AA; sensor B low is P08B6.

Likely causes

Signal wire chafed through and shorted to ground in the pedal area
Open signal wire or missing 5 V reference (connector off, broken wire)
Failed clutch pedal position sensor A
Shared 5 V reference pulled down by another sensor on the same circuit

Symptoms

  • Malfunction indicator lamp on after one trip
  • Start-stop and cruise control unavailable
  • Engine may refuse to crank on vehicles that release the starter via the sensor

Repair estimate

DifficultyEasyDIY possible
Parts and labour€50–300
Time0.3–1.5 h

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

Parts involved

clutch pedal position sensor awiring harnessecm

Related codes

P08AAP08A7P08A8P08B6P0807P0641

References: gsi.ext.gm.com, gsi.ext.gm.com, fordservicecontent.com.