Low, degraded or contaminated transmission fluid; Pressure control solenoid A sticking or worn internally; Blocked or clogged transmission filter or valve body passages; Damaged wiring, poor connector contact or corrosion in the solenoid circuit; Worn valve body, internal leakage or worn clutch packs causing pressure loss; Faulty transmission control module or outdated software calibration; Failing pump giving low line pressure.

P0746

Pressure Control Solenoid A Performance/Stuck Off.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
7: AreaTransmission
46: FaultThe specific fault in that area

What it means

P0746 means the transmission control module has detected that Pressure Control Solenoid A is not performing as commanded, or is stuck off. The module compares the commanded line pressure or gear ratio against what it actually sees, and sets the code when the solenoid fails to deliver the expected hydraulic pressure. The exact circuit and solenoid layout vary by transmission, so check the model-specific information.

Symptoms

Harsh, delayed or flared gear changes
Transmission slipping or engine revs rising without matching acceleration
Car stuck in limp mode or a single fixed gear
Gearbox warning light or malfunction indicator lamp on
Poor acceleration or reduced fuel economy
Gearbox overheating or a burning smell from the fluid

Possible causes

Low, degraded or contaminated transmission fluidlikely
Pressure control solenoid A sticking or worn internallylikely
Blocked or clogged transmission filter or valve body passagespossible
Damaged wiring, poor connector contact or corrosion in the solenoid circuitpossible
Worn valve body, internal leakage or worn clutch packs causing pressure losspossible
Faulty transmission control module or outdated software calibrationrare
Failing pump giving low line pressurerare

How to diagnose

Read all stored and pending codes and review freeze frame data for gear, temperature and load at the time of setting
Check the transmission fluid level and condition, following the manufacturer's procedure for that model, and look for leaks
Inspect the transmission wiring harness and connectors for chafing, fluid ingress, corrosion and pin damage
Check the battery and charging voltage, as low voltage can upset solenoid control
Check for related codes and any technical service bulletins or software updates for the vehicle
Monitor live data for commanded versus actual line pressure, gear ratio and slip while road testing
Test the solenoid resistance and its wiring for continuity and shorts against the specification for that transmission
Drop the pan and inspect the filter and debris for clutch material or metal, where access allows

How to fix

Correct the fluid level or replace degraded fluid and the filter using the specified type
Replace the pressure control solenoid A, or the solenoid pack, if it is faulty
Repair or replace damaged wiring and connectors in the solenoid circuit
Clean or overhaul the valve body, or replace it if worn or blocked
Repair or rebuild the transmission if internal wear or pump pressure loss is confirmed
Update the transmission control module software only if an outdated calibration is a known cause for that model

Can I keep driving?

Medium severity

The car may be driveable for a short time, but continued use with slipping or low pressure can quickly damage clutches and overheat the gearbox. Get it checked soon, and avoid heavy loads or towing; stop driving if it slips badly or goes into limp mode repeatedly.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.