OBD-II trouble code
P0747: Pressure Control Solenoid "A" Stuck On
The transmission control module detected that pressure control solenoid A is stuck in the on position, so line pressure stays too high. Expect harsh, slamming shifts — address it promptly to avoid clutch and internal damage.
Quick facts
- System
- Powertrain
- Category
- Transmission / Pressure Control
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $150 – $900
- DIY difficulty
- Shop recommended
What does P0747 mean?
P0747 sets when the transmission control module (TCM) or PCM commands pressure control solenoid "A" to change state and the solenoid stays stuck in its energized, or "on," position. Instead of modulating line pressure the way it's told, the solenoid holds the transmission at a fixed pressure — and depending on the solenoid design, that usually means pressure stays too high.
Pressure control solenoid A regulates the mainline hydraulic pressure that applies the clutches and bands. When it's stuck on and pressure can't be reduced, shifts land hard — the transmission slams into gear and feels harsh, especially on the 1-2 and 2-3 upshifts. Unlike the low-pressure failure (which causes slipping), a stuck-on high-pressure condition tends to be firm and abrupt. The module will often flag the fault and may limit shifting to protect the drivetrain.
The cause is not always the electrical part of the solenoid. Very often the coil is fine and the problem is mechanical: debris, varnish, or a burr holding the valve open so it won't return. That's why fluid condition matters — dirty or degraded fluid promotes the sticking that causes P0747. Diagnosis looks at fluid first, then the solenoid's electrical health and its ability to move freely, and finally the valve body. Chronic harsh shifting stresses the clutch packs and mounts, so while the vehicle usually still moves, it's worth fixing promptly rather than living with the slamming shifts.
Common causes
- Debris or varnish holding the solenoid valve in the open position
- Dirty or degraded transmission fluid promoting valve sticking
- Mechanically failed or seized pressure control solenoid A
- Worn or contaminated valve body keeping the solenoid from returning
- Electrical fault commanding the solenoid on continuously
- Restricted transmission filter contributing to contamination
- Faulty transmission control module in rare cases
Symptoms
- Check engine light on with P0747 stored
- Harsh, slamming, or abrupt shifts
- Delayed engagement into drive or reverse
- Transmission running hotter than normal
- Falling into limp mode in some cases
- Reduced fuel economy when shifts are mistimed
Diagnostic steps
- 1.Check transmission fluid level and condition first — dirty fluid is a leading cause of a sticking solenoid and the cheapest thing to rule out.
- 2.Scan for companion transmission codes; a general P0700 confirms the TCM has stored transmission faults.
- 3.Read line-pressure live data if the transmission supports it, and compare commanded versus actual pressure.
- 4.Inspect the solenoid connector and harness for damage that could be holding the circuit on.
- 5.Resistance-check pressure control solenoid A and, where possible, verify it moves freely rather than sticking.
- 6.If the solenoid tests good, inspect the valve body for varnish, debris, or bore wear keeping the valve open.
Repair cost
$150 – $900
A transmission fluid and filter service ($150-$350) is the first step and sometimes frees a sticking valve. A pressure control solenoid replacement runs roughly $250-$700 depending on whether it's externally accessible or requires dropping the pan or valve body. Valve-body cleaning or replacement is the higher end. Confirm fluid condition and line pressure before replacing internal parts.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with transmission shift solenoid replacement preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
Leave this one to a qualified shop. It typically involves emissions-critical components, refrigerant handling, or other work that requires manufacturer-grade tooling, training, or certification. DIY attempts often produce a more expensive problem than the original code.