P1745 Fault Code in Ford: Causes, Symptoms, and Fixes

The Transmission Control Module (TCM) monitors hydraulic line pressure. If the pressure is higher than expected for the commanded condition, it sets P1745. This often relates to line pressure solenoid / pressure control solenoid or a mechanical hydraulic issue inside the transmission.

Possible Causes:

1. Faulty Line Pressure Control Solenoid (stuck or shorted).
2. Wiring issues – short to ground or short to power in solenoid circuit.
3. Faulty Transmission Control Module (TCM/PCM).
4. Blockage in valve body or hydraulic passages.
5. Excessive wear in oil pump or pressure regulator valve.
6. Low or contaminated ATF fluid.
7. Overheating transmission.

Symptoms:

1. Harsh or erratic shifting.
2. Vehicle stuck in limp mode (stays in 2nd/3rd gear).
3. Transmission overheating.
4. Check Engine Light (CEL) or Transmission Warning Light.
5. Shudder or jerks during acceleration.

Diagnosis:

1. Scan for related codes (esp. solenoid or pressure codes).
2. Check ATF level and condition – burnt or dirty fluid can cause sticking valves.
3. Inspect wiring & connectors for pressure solenoid.
4. Measure solenoid resistance and compare with specs.
5. Check live data – line pressure vs commanded pressure.
6. If electrical system is fine → suspect valve body or pump issue.

Repair Steps:

1. Replace/repair line pressure solenoid if faulty.
2. Repair wiring/connectors.
3. Flush or replace ATF fluid + filter.
4. Clean or replace valve body if sticking valves found.
5. In severe cases → pump/TCM replacement or transmission overhaul.