Shift solenoids are used by the ECU to force pressurized hydraulic fluid (aka transmission fluid) to move different parts like clutches and gears. If there is an abnormally high voltage signal coming from the shift solenoid A control circuit, a DTC P0974 will be recorded.
How severe is the code?
Diagnostic code P0974 is one of the most severe OBD2 codes you can have. When a shift solenoid goes bad, you may experience a number of driving issues, including harsh shifting and a complete inability to shift gears.
Symptoms
Symptoms of a P0974 include:
- Shifting is generally harsh
- The transmission cannot shift into gear
Causes
- Low or dirty transmission fluid
- Damaged connectors/wiring
- Faulty shift solenoid
How to diagnose the code?
The best way to start diagnosing an OBDII P0974 trouble code is to first check the transmission fluid level and condition. If that checks out, the wiring and connectors should be inspected for signs of damage and corrosion. After that, the valve body will need to be checked.
What repairs will fix P0974?
- Service the transmission
- Replace or repair damaged wiring/connectors
- Replace the shift solenoid
Related codes
P0972 – Shift solenoid “A” control circuit range/performance
P0973 – Shift solenoid “A” control circuit low