P08A1 code meaning
Gear Lever Y Position Sensor 2 Circuit Low
Powertrain system Generic code P08xx codes Check engine light
What P08A1 means
The selector lever's Y-axis sensor 2 is one of two redundant Hall sensors that send the lever travel as a PWM duty cycle. GM documents P08A1 for its electronic range selection: the code sets when the measured duty cycle of Y sensor 2 drops below 17 % (2019 ECM and ICCM tables) or below 5 % (Cadillac XT4 2019, ECM tables 2023–2025), checked 3 of 4 samples at 25 ms or 10 of 12 in later years. Typical reasons are a signal wire shorted to ground, a missing sensor supply or a dead sensor output. Type B, MIL after two trips. Unlike P08A0 this is a pure signal limit, not a plausibility check; high is P08A2. Sensor 1 keeps the selector working.
P08A1 at a glance
- Check engine lightYes, usually on
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 2 hours
- Clears after repairAfter a drive cycle
Symptoms of P08A1
- Check engine light after two drives
- Shifter warning message in the cluster
- Normally no change in driving, sensor 1 takes over
Common causes of P08A1
- Most likelySensor 2 signal wire shorted to ground
- PossibleSensor supply open or connector backed out
- PossibleSensor 2 in the selector assembly without output
- Less likelyConnector corrosion from liquid in the console
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Gear lever y position sensor 2Wiring harnessTCM
What each part of P08A1 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 8 | Area: transmission. |
| A1 | The exact fault in that area. |
What to do next
- Note P08A1 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P08A1
What does P08A1 mean?
P08A1 means "Gear Lever Y Position Sensor 2 Circuit Low". The selector lever's Y-axis sensor 2 is one of two redundant Hall sensors that send the lever travel as a PWM duty cycle. It is a generic code, so it means the same on every make.
Is it safe to drive with P08A1?
Drive gently and only to a workshop. With P08A1 the car can go into limp mode (reduced power) to protect itself.
Will P08A1 fail an emissions test?
P08A1 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is P08A1 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. This is a job for a workshop.
Will P08A1 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.