On vehicles with an automated manual transmission / semi automatic transmission, gears are changed by the shift and select actuator assembly, which consists of motors and sensors (stroke sensor and select stroke sensor). If the TCM detects a problem with the shift and select actuator, a P0909 DTC will be saved.
How Serious is the Code?
In terms of severity, a P0909 diagnostic trouble code is extremely serious, because it means the TCM cannot change gears the way it is programmed to. This can lead to serious drivability issues and/or an inoperable vehicle.
Symptoms of a P0909 include:
- Harsh, delayed or erratic shifts
- Transmission get stuck in a single gear
- Transmission will not shift into or out of a gear
- The transmission refuses to engage gears
- Clutch slipping
- The engine seems to misfire
- Failed shifter assembly
- Failed clutch position sensor
- Failed clutch actuator
- Shift and select actuator assembly
- Stroke sensors
- Control linkages out of adjustment
- Damaged wiring and/or connectors
- Clutch or transmission failure
How to Diagnose the Code?
The diagnostic procedure for a P0909 OBDII trouble code will be specific to your type of transmission. But it will involve a series of electrical tests and mechanical tests to determine which transmission parts have failed.
What Repairs Will Fix P0909?
- Replace shift and select actuator assembly
- Replace stroke sensors
- Replace shifter mechanism
- Replace clutch position sensor
- Replace clutch actuator
- Replace clutch
- Repair or replace damaged wiring or connectors
- Adjust or repair control linkages
- Repair or replace transmission
- P0905 – Gate Select Position Circuit Range/Performance
- P0906 – Gate Select Position Circuit Low
- P0907 – Gate Select Position Circuit High
- P0908 – Gate Select Position Circuit Intermittent
- P0910 – Gate Select Actuator Circuit/Open