Pressure Control Solenoid A Performance or Stuck Off
The P0746 code indicates that the transmission control module (TCM) or powertrain control module (PCM) has detected a malfunction in the operation of pressure control solenoid 'A'. Specifically, the computer determined that the solenoid is not performing as expected or is stuck in the 'off' position, preventing proper hydraulic pressure regulation within the transmission.
This code is considered high severity because driving with improper transmission line pressure can cause severe internal transmission damage. It should be diagnosed and repaired immediately to prevent costly transmission failure.
Common symptoms
- Check Engine Light illuminated
- Transmission slipping during shifts
- Harsh or erratic shifting
- Vehicle fails to shift into certain gears
- Decreased fuel economy and poor acceleration
Likely causes
- Low or contaminated transmission fluid
- Defective pressure control solenoid 'A'
- Clogged transmission fluid filter or internal hydraulic blockages
- Damaged or corroded wiring and connectors in the solenoid circuit
- Internal transmission mechanical failure (e.g., worn clutch packs or pump)
- Faulty Transmission Control Module (TCM) or PCM (rare)
What to check before replacing parts
Check transmission fluid level and condition
Look for: Look for low fluid levels, a burnt smell, or metal debris indicating internal damage or the need for a fluid service.
Inspect wiring and connectors to the transmission
Look for: Look for frayed wires, corrosion, or loose connections at the transmission harness that could interrupt the solenoid circuit.
Test pressure control solenoid 'A' resistance
Look for: Use a multimeter to measure the internal resistance of the solenoid; an out-of-spec reading indicates a failed solenoid coil.
Perform a transmission line pressure test
Look for: Connect a mechanical pressure gauge to the transmission test port; pressure readings that do not match service manual specifications indicate a stuck solenoid or pump issue.
Command the solenoid using a bidirectional scan tool
Look for: Listen for an audible click or monitor pressure changes; lack of response confirms the solenoid is stuck off or mechanically failed.
This page explains the generic P0746 definition and is general reference information, not a diagnosis for your specific vehicle. Actual causes, severity, and repairs vary by make, model, engine, and mileage — always confirm with a scan tool and a qualified technician before replacing parts.
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