OBD-II trouble code
P0745: Pressure Control Solenoid "A" Electrical
The transmission control module detected an electrical fault in pressure control solenoid A — the circuit that regulates main line pressure. Expect harsh or slipping shifts, and often limp mode, until the wiring or solenoid is repaired.
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 P0745 mean?
P0745 sets when the transmission control module (TCM) or PCM sees an electrical problem in the circuit that drives pressure control solenoid "A." Where the performance code for this solenoid (P0746) is about the solenoid not delivering the commanded pressure, P0745 is the pure electrical fault: an open, short, or out-of-spec resistance in the solenoid or its wiring, so the module cannot control it the way it expects.
Pressure control solenoid A — often called the line-pressure, EPC, or variable-force solenoid — regulates the mainline hydraulic pressure inside the transmission. Line pressure is what firmly applies the clutches and bands during every shift, so this is one of the most important solenoids in the valve body. When the module loses reliable electrical control of it, the transmission can no longer set the right pressure, and it usually defaults to a fixed high pressure or drops the transmission into a fail-safe limp mode to protect the internals.
Because P0745 is an electrical code, the diagnosis starts at the circuit rather than the fluid: connector condition, harness wiring, and the solenoid's coil resistance. A corroded connector or chafed harness is a common and inexpensive cause, but the solenoid itself can also fail internally. It's worth confirming the electrical fault before dropping the pan, since sometimes the fix is as simple as a connector repair. Left unaddressed, running in limp mode or at the wrong pressure lets the clutches slip, and slip generates heat that shortens the life of the transmission.
Common causes
- Corroded, loose, or damaged connector at the solenoid or transmission case
- Open, shorted, or chafed wiring in the solenoid circuit
- Failed pressure control solenoid A (open or shorted coil)
- Internal transmission wiring harness fault
- Poor ground or supply voltage to the transmission control module
- Contaminated fluid that has damaged the solenoid electrically
- Faulty transmission control module in rare cases
Symptoms
- Check engine light on with P0745 stored
- Harsh, delayed, or flaring shifts
- Transmission slipping under load
- Transmission stuck in a single gear (limp mode)
- Transmission running hotter than normal
- Reduced fuel economy when clutches or converter slip
Diagnostic steps
- 1.Scan for companion transmission codes; a general P0700 confirms the TCM has stored transmission faults.
- 2.Inspect the solenoid connector and external harness for corrosion, damage, or loose pins.
- 3.Resistance-check pressure control solenoid A against the manufacturer's specification for an open or shorted coil.
- 4.Check for a short to ground or to power in the solenoid control wiring back to the module.
- 5.Verify the transmission control module has good power and ground before condemning it.
- 6.Check fluid level and condition while the pan is accessible — contamination can damage a solenoid electrically.
Repair cost
$150 – $900
A connector or wiring repair can be inexpensive if the solenoid itself is healthy. A pressure control solenoid replacement typically runs $250-$700 depending on whether it's externally accessible or requires dropping the pan or valve body. Confirming the electrical fault with a resistance and wiring check first is worth the labor 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.