In order to move your transmission into the next gear, shift solenoids have to direct pressurized hydraulic fluid down the correct channel. If the ECU detects a low voltage signal coming from the shift solenoid A (communication) circuit, it will save a P0973 DTC.
How Serious is the Code?
The P0973 diagnostic trouble code is very serious, because it means your transmission will not be able to shift properly. You may experience a number of transmission problems, including unusually harsh shifting and even the complete failure to shift.
Symptoms of a P0973 include:
- Unusually hard shifts
- Transmission fails to shift into gear
- Dirty or low transmission fluid
- Damaged wiring/connectors
- Failed shift solenoid
How to Diagnose the Code?
Diagnosing a P0973 OBDII code should start with a check of the condition and level of the transmission fluid. If it’s in good condition, then the wiring and connectors along the transmission wiring harness should be carefully examined for signs of broken wires and damaged/broken connectors if everything appears to be in good shape, then the shift solenoid will need to be tested.
What Repairs Will Fix P0973?
- Service the transmission
- Replace or repair damage wiring/connectors
- Replace shift solenoid
- P0972 – Shift Solenoid “A” Control Circuit Range/Performance
- P0974 – Shift Solenoid “A” Control Circuit High