A DTC P0998 indicates that the ECU has detected a low voltage signal from the shift solenoid F control circuit. This means the computer is unable to command the activation and deactivation of the solenoid.
How severe is the code?
Most of the time, transmission issues associated with a P0998 diagnostic code start out very minor. But they can worsen to the point where your vehicle is almost impossible to drive.
Symptoms
Symptoms of a P0998 include:
- The transmission feels like it’s shaking when shifting gears
- The transmission does not shift into gear
Causes
- Transmission fluid level is too low
- Transmission fluid and filter need to be changed
- Damaged/broken wires
- Broken/corroded connectors
- The shift solenoid has stopped working
How to diagnose the code?
Since the level and condition of the transmission fluid will directly affect the operation of each shift solenoid, this should be the first thing to check when diagnosing a P0998 OBDII fault code. The wiring and connectors along the transmission wiring harness are also a factor. If no issues have been detected so far, the shift solenoid F will need to be directly tested.
What repairs will fix P0998?
- Service the transmission
- Replace or repair damaged wires/connectors
- Replace the shift solenoid