Fault code P0745 – a step-by-step guide to diagnosing and fixing it

Error code P0745 is displayed and the check engine light is on - what does this mean?

The OBD system detects a fault in the pressure regulator solenoid valve for the transmission control unit. This DTC P0745 indicates a problem with the pressure control solenoid A, which is responsible for the proper functioning of the automatic transmission. The error code can occur with various manufacturers and mainly affects the hydraulic control of the transmission.

What causes can this error code have?

• Defective pressure control solenoid A
• Damaged wiring to the solenoid valve
• Corroded or loose plug connections
• Blocked hydraulic lines in the transmission
• Contaminated or old transmission oil
• Defective transmission control unit (TCM)
• Mechanical damage to the valve body
• Faulty pressure sensors

What symptoms occur in parallel with fault code P0745?

• Shifting problems: The transmission shifts jerkily or with a delay between gears
• Emergency running program: The vehicle gets "stuck" in a gear and no longer shifts
• Increased fuel consumption: Fuel consumption increases significantly due to inefficient gear changes
• Unusual noises: Whistling or whirring noises from the transmission area
• Jerking when starting off: The vehicle jerks when starting or at low speeds
• Transmission overheating: The transmission becomes unusually hot

How can the problem with error code P0745 be rectified?

• The repair usually requires a systematic diagnosis, as several components may be affected.
• Change the transmission oil and filter: Replace old or contaminated oil with fresh ATF and replace the transmission filter at the same time
• Replace pressure control solenoid A: Locate the defective solenoid valve in the valve body and replace with a new original or equivalent spare part
• Check wiring and plug connections: Check all electrical connections to the solenoid for damage, corrosion or loose contacts and repair them
• Clean or replace the valve body: Remove the entire valve body, clean it professionally or replace it completely if it is severely damaged
• Diagnose the transmission control unit: Test the TCM with special diagnostic software and reprogram or replace if necessary
• Measure hydraulic pressure: Use pressure gauges to check the system pressure and rule out mechanical defects in the transmission