Powertrain, generic · Transmission

P08A0 Gear Lever Y Position Sensor 2 Circuit Range/Performance

Check engine lightOn
EmissionsNot relevant
Drive cycleRequired
Limp modePossible

Sensor 2 is the redundant second Hall sensor that reports the Y-axis travel of an electronic selector lever as a PWM duty cycle. GM uses it in its electronic range selection (ECM and ICCM tables 2019–2025, Cadillac XT4 among them). P08A0 is set when sensor 2 reports a lever path outside the shifter gate (tolerance 5.5 %, ICCM 6–11 % of duty cycle), its frequency check fails, or it disagrees with Y sensor 1 by more than 12 %. Debounce is 3 of 4 samples at 25 ms (2025: 10 of 12). Type B, MIL after two trips. Low/High of the same sensor are P08A1/P08A2. GM's patent lets the other sensor carry on; only when both are invalid may the module ask for park.

Likely causes

Sensor 2 in the selector assembly drifting or faulty
Selector mechanism worn, bent or binding, lever leaves its nominal path
Loose contact or interference on the PWM signal line
Spilled liquid in the centre console

Symptoms

  • Check engine light after two drives
  • Shift lever message or occasional unaccepted range selection
  • Usually still drivable, sensor 1 takes over

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€150–900
Time0.5–2 h

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

Parts involved

gear lever y position sensor 2wiring harnesstcm

Related codes

P08A1P08A2P08A3P08A5P082DP089B

References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com, patents.google.com.