P2772Four Wheel Drive (4WD) Low Switch Circuit Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2772 flags a low-range switch whose signal is electrically valid but does not fit what the drivetrain is actually doing. No manufacturer documents P2772 publicly. The natural cross-check is the one GM describes under P2771: the control unit derives the active range from turbine or input speed, output speed and the resulting ratio, then compares that with the switch. A switch reporting low while the ratio shows high, or a switch that never changes after a range shift, fits this code. Root causes are mostly mechanical: a worn shift fork or encoder, a switch out of adjustment, or a speed signal disturbed by shaft play. CARB requires such rationality checks for inputs to monitored systems. The driver may see a flashing 4WD lamp or find low range unavailable.
- What you may notice
- Flashing 4WD indicator or range message on the cluster
- Low range refused or engaged only after several attempts
- Warning light depending on manufacturer
- Likely causes
- LikelyLow-range switch or encoder worn or out of adjustment
- PossibleRange shift not completed (shift fork, actuator or linkage)
- PossibleOutput or turbine speed signal distorted, so the calculated range is wrong
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.