P0927Gear Shift Reverse Actuator Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- Set when the drive circuit of the reverse shift actuator of an automated manual gearbox shows a voltage that is too high for the current switching state. Common reasons are a valve or motor line shorted to battery voltage or a driver stage that no longer switches off; on some circuit designs an open load also reads high. No manufacturer documents this code publicly. A ZF patent describes double-acting shift cylinders with a 3/2 solenoid valve on each chamber, and an Isuzu patent reverses an electric shift motor according to shift direction, so the reverse direction has its own output. CARB requires circuit checks on outputs. P0926 is the opposite low fault, P0924 the open circuit, P0923 the forward direction. A permanently energised actuator can force a gear, so shifting is usually locked.
- What you may notice
- Transmission warning light on
- Gearbox locks in one gear or refuses to shift
- Possible grinding when a gear is pushed unintentionally
- Likely causes
- LikelyDrive wire shorted to battery voltage
- PossibleDriver stage in the control module stuck on
- RareOpen coil or winding read as high on some circuit designs
- 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 – €2,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.