P0912 code meaning
Gate Select Actuator Circuit Low
Powertrain system Generic code P09xx codes Check engine light
What P0912 means
Set when the drive circuit of the gate select actuator of an automated manual gearbox shows a voltage that is too low for the current switching state, which usually means a short to ground on a motor or control line, or an internal short in the actuator. Many controllers then switch the affected output off to protect the driver stage. No manufacturer documents this code publicly. Isuzu and Hyundai/Kia describe in their patents select and shift actuators built as electric motors and driven by the transmission controller, which is the hardware this circuit check covers; CARB requires circuit monitoring of such outputs. P0913 is the matching high fault, P0910 an open circuit and P0911 a plausibility fault. With the select actuator disabled, the gearbox can no longer change gates.
P0912 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyHard
- Typical labor0.5 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0912
- Check engine or transmission warning light on
- No gate change possible, gearbox stays in current gear or neutral
- Vehicle may not pull away
Common causes of P0912
- Most likelyActuator wire chafed through and shorted to ground
- PossibleInternal short in the select motor, e.g. from brush debris
- Less likelyFaulty driver stage in the transmission control module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Gate select actuatorWiring harnessTCM
What each part of P0912 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 9 | Area: transmission. |
| 12 | The exact fault in that area. |
What to do next
- Note P0912 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 P0912
What does P0912 mean?
P0912 means "Gate Select Actuator Circuit Low". Set when the drive circuit of the gate select actuator of an automated manual gearbox shows a voltage that is too low for the current switching state, which usually means a short to ground on a motor or control line, or an internal short in the actuator. It is a generic code, so it means the same on every make.
Is it safe to drive with P0912?
Drive gently and only to a workshop. With P0912 the car can go into limp mode (reduced power) to protect itself.
Will P0912 fail an emissions test?
Yes, it can. P0912 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0912 to fix?
Difficulty: hard. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will P0912 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.