When you shift your vehicle into gear, a series of sensors and levers within the gear shift forward actuator tells the ECU/TCM what gear you selected. The computer then sends an electrical signal to electric motor that moves the transmission parts around to actuate the gear. If there is an issue with the gear shift forward actuator, a P0920 DTC will be saved.
How Serious is the Code?
The P0920 diagnostic trouble code is actually pretty serious, because essentially it means you will not be able to easily shift into or out of a forward gear.
Symptoms of a P0920 include:
- Erratic transmission behavior
- Transmission will not engage or disengage a forward gear
- Damaged wiring and/or connectors
- Failed gearshift forward actuator
- Damaged gear guide rail
- Damaged shift shaft
- Internal mechanical issues
- ECU/TCM issues or failure
How to Diagnose the Code?
To diagnose a P0920 OBDII trouble code, the technician will need to carefully inspect the wiring and connectors between the shifter and the transmission. It will also need to check the gear shift forward actuator, along with the condition of the gear guide rail and shift shaft. If none of these are at fault, the ECU programming, and possibly the transmission itself, will need to be checked.
What Repairs Will Fix P0920?
- Repair or replace any damage wiring or connectors
- Replace gearshift forward actuator
- Repair or replace gear guide rail
- Repair or replace shift shaft
- Repair internal mechanical fault(s)
- Reprogram or replace ECU/TCM
- P0914 – Gear Shift Position Circuit
- P0915 – Gear Shift Position Circuit Range/Performance
- P0916 – Gear Shift Position Circuit Low
- P0917 – Gear Shift Position Circuit High
- P0918 – Gear Shift Position Circuit Intermittent
- P0919 – Gear Shift Position Control Error