P0745
PowertrainPressure Control Solenoid 'A' Malfunction
You'll usually notice this one before the scanner does. The gearbox starts shifting harshly or hanging onto a gear too long, the revs flare when you accelerate, and on a bad day the car drops into limp mode and refuses to go past second or third. Behind all that is pressure control solenoid 'A', the part that regulates hydraulic line pressure inside an automatic gearbox. When the transmission control module spots an electrical fault or odd performance from that solenoid, it logs P0745 and often pulls the gearbox into a safe mode to stop you cooking it.
ⓘ Information only. This page provides general educational information about fault code P0745. We do not assess the urgency or safety implications of any specific fault. That requires in-person diagnosis by a qualified mechanic. Full terms.
Recommended next steps
Whether a fault is urgent, drivable, or routine depends entirely on the cause on a specific vehicle, and that can only be determined by a qualified mechanic with diagnostic equipment. If a warning light is illuminated, the most reliable next step is professional diagnosis.
What does P0745 mean?
P0745 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Pressure Control Solenoid 'A' Malfunction.
This is a standardised OBD-II code. The technical definition is the same regardless of the make or model of vehicle, although specific causes and symptoms can vary between vehicles.
Symptoms commonly associated with this code
Symptoms that drivers often report alongside this code. Not all may apply to every case:
- • Check engine light on, sometimes with a separate gearbox warning depending on the car
- • Harsh or delayed gear changes, worst when you're accelerating under load
- • Revs climb but the car doesn't pull with them, the classic slipping feeling
- • Stuck in a single gear, often second or third, with no upshift
- • Gearbox running hot, or a burnt smell from the fluid
- • Drops into limp mode and stays there until you restart
Possible causes
Causes commonly associated with P0745, listed in approximate order of typical investigation. The actual cause on a specific vehicle can only be confirmed by professional diagnosis.
- 1. The pressure control solenoid itself failing electrically or sticking mechanically, the most common cause once the wiring checks out
- 2. Low or burnt automatic transmission fluid, or the wrong spec fluid in there from a previous service. The solenoid relies on clean fluid at the right pressure to work
- 3. Damaged, corroded, or loose wiring and connectors in the solenoid circuit, especially where the loom passes into the gearbox
- 4. Blocked or worn passages in the valve body restricting how the solenoid controls pressure
- 5. Metal or clutch debris in the sump pan, which points to wear further inside the box
- 6. A faulty TCM or PCM, rare but possible if everything else tests good
- 7. An open circuit, short, or poor earth in the solenoid wiring throwing a false fault
How mechanics typically diagnose
A typical diagnostic sequence used by mechanics, provided here for educational reference only. Diagnostic work should be performed by a qualified mechanic with the appropriate tools and training.
- 1. Check the fluid level and condition first. Pull the dipstick if it has one, or check at the right temperature on a sealed box. Burnt, dark, or low fluid explains a lot of these before you touch anything electrical
- 2. Read all stored codes and the freeze frame data. Note whether it's an electrical fault or a performance one, and look for shift solenoid codes alongside it
- 3. Inspect the wiring and connector at the gearbox for corrosion, chafing, or a loose pin. The transmission connector is a known weak spot for moisture ingress
- 4. Test the solenoid resistance with a multimeter against the manufacturer spec, and check it's getting a clean supply and earth
- 5. Run a hydraulic pressure test to see whether the solenoid is actually controlling line pressure or the valve body is at fault
- 6. If the fluid shows metal or clutch material, drop the sump pan and inspect properly. That changes the whole job from a solenoid swap to a gearbox decision
Common questions about P0745
How do I know if it's the solenoid or just a wiring fault? +
Test the circuit before you condemn the solenoid. A surprising number of P0745s are down to a corroded or loose connector at the gearbox, a chafed wire, or a bad earth, all of which throw the same code as a dead solenoid. Measure the solenoid's resistance against spec and check it has a clean supply and earth with the connector unplugged. If the wiring is sound and the resistance is out, or it's wildly intermittent, then the solenoid is the culprit. Wiring repairs cost you a connector and an hour. A solenoid means dropping the pan.
How long does the repair actually take? +
If it's wiring or a connector, a competent garage sorts it in an hour or two. A solenoid replacement is usually half a day once you account for dropping the pan, draining and refilling the fluid, and sometimes pulling the valve body to reach it. If the solenoid is integrated into the valve body, as it is on a lot of modern autos, expect the best part of a day. And if the pan turns up metal debris, you're into a much bigger conversation about the gearbox itself rather than a quick fix.
Is a cheap aftermarket solenoid worth fitting or should I stick with OEM? +
On a gearbox part I'd lean towards OEM or a quality OE-equivalent brand. Pressure control solenoids are precision items and the bargain-bin ones from unknown sellers have a habit of giving the same fault again within months, which means doing the whole pan-off job twice. The labour to fit it dwarfs the price difference between a no-name part and a proper one, so saving £30 makes no sense here. Buy the right solenoid once and use fresh fluid of the correct spec when you refill, because the wrong fluid will kill a brand new solenoid just as fast.
Information only, not professional advice
The information on this page is provided for general guidance and educational purposes only. It is not a substitute for diagnosis or repair advice from a qualified mechanic. Always verify any fault before paying for repairs. carfaultcodes.co.uk accepts no liability for decisions made based on this information. Full terms →