What it means
The output driver for the shift motor reports current or junction temperature above its protection threshold. Sustained high load or short-circuit fault.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The shift motor driver supplies current to move the transmission gear actuator and monitors its own current and temperature for protection. This code sets when current draw or driver junction temperature exceeds its protection threshold, which can occur if the motor stalls or its phases short together.
Common causes
Most likely first.
- Motor stalled - high stall current
- Short between motor phases
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
How to diagnose it
- Save freeze-frame data and any driver temperature or current readings, and note whether the fault occurred during a shift or after repeated actuator operation.
- Inspect the shift motor and its mechanism for visible obstruction or binding, and check the U, V, and W wiring for heat damage or phase-to-phase contact.
- Check the phase circuits for shorts and the motor for abnormal resistance or binding using the manufacturer's specification and procedure.
- If the motor and wiring are sound, assess the driver outputs and temperature readings with the manufacturer's diagnostic procedure.
- Repair the confirmed mechanical bind, phase short, motor fault, or driver fault, then verify that current and temperature remain within specification during shifts.
Common fixes
- Repair wiring damage that allows shift motor phases to contact each other.
- Free or repair a shift actuator mechanism confirmed to be stalled, following the manufacturer's procedure.
- Replace a shift motor with a confirmed internal fault causing excessive current.
- Repair or replace the shift motor driver if it overheats or reports excessive current with a sound motor and harness.
Can I keep driving?
Stop driving if the transmission is slipping, unable to shift, or has entered limp mode; repeated high current or overheating can damage the shift motor driver further. If the fault appeared once and shifting remains normal, avoid repeated gear cycling and arrange prompt diagnosis.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.