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.
What Transmission Do I Have?
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
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
 
Causes
- 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 Transmission Do I Have?
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
 
Related Codes
- 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