P0973Powertrain
Powertrain · SAE
Shift Solenoid A Control Circuit Low
Meaning
The transmission control module has detected that the signal in the shift solenoid A (SSA) control circuit is below the expected minimum threshold: short to ground or excessively low drive current in the command circuit.
Common causes
- Short to ground in the SSA solenoid control wire
- SSA solenoid with internally shorted coil (too-low resistance)
- Damaged insulation in the SSA control wiring
- Oxidised connectors creating a low-resistance path to ground
- Internal TCM fault on the SSA solenoid driver
Symptoms
- Check engine or transmission warning light on
- Transmission in limp mode
- Abnormal or absent gear shifts in SSA-governed gears
- Transmission slippage
Severity
High: the short circuit in the SSA circuit prevents correct solenoid operation, causing abnormalities in the transmission gear ratios.
What to do
- Measure SSA solenoid resistance with a multimeter (check for internal short)
- Check for short to ground in the SSA control wire
- Inspect wiring and connectors for damaged insulation or corrosion
- Measure command current to the solenoid with a clamp ammeter
- Replace SSA solenoid or TCM depending on diagnosis