To prevent an unintentional rollback situation, modern vehicles are equipped with what is called a gearshift lock solenoid. When the computer detects that all conditions are met (foot on the brake pedal, gearshift lever lock button pressed) to safely move the vehicle out of park, the gearshift lock solenoid releases and allows the transmission to shift into gear. A DTC P0928 means there is an electrical issue in the control circuit of this solenoid.
How severe is the code?
Obviously, a diagnostic code P0928 is quite serious, as it likely means you will not be able to drive your vehicle.
Symptoms
Symptoms of a P0928 include:
Transmission cannot shift out of park
Causes
- Low or dirty transmission fluid
- Low battery voltage
- Bad fuse(s) or fuse link(s)
- Damaged wiring or connectors
- Gearshift lock solenoid
- Faulty brake light switch
How to diagnose the code?
Diagnosing an OBDII P0928 fault code should begin with a thorough inspection of the wiring and connectors related to the gearshift lock solenoid (there may be a short circuit or liquid damage if something was spilled around the gearshift lever). Battery voltage, fuses, fuse links, and relays should also be tested. The brake light switch must also be considered, along with the condition of the transmission fluid.
What repairs will fix P0928?
- Change transmission fluid/filter
- Charge or replace the battery
- Replace any blown fuse or fuse link
- Replace any damaged wiring or connector
- Replace the gearshift lock solenoid
- Replace the brake light switch