P0903
PowertrainTransmission Shifthigh severityGate Select Actuator Circuit Open
What P0903 Means
The gate select actuator circuit in an automated transmission has an open electrical fault. This prevents the transmission from selecting the correct gear gate during shifts.
Symptoms
- Harsh or failed shifts
- Transmission stuck in gear
- Warning light on
Common Causes
- Damaged actuator wiring
- Faulty gate select actuator
- Corroded connector
- Failed transmission control module
Diagnostic Steps
- Scan for related transmission codes
- Inspect actuator wiring and connector
- Measure actuator circuit resistance
- Test or replace gate select actuator
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