What does it mean?
P1745 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Problem in Shift Control System; Servo Control Valve Stuck OFF or Servo Valve Stuck OFF .
Symptoms
- Engine RPM flares during a specific shift because the element never holds
- Slipping, delayed or missing engagement in the affected gear
- Harsh recovery shift as the module raises pressure to compensate
- MIL (check engine lamp) on with a transmission warning
- Burnt fluid smell and rising transmission temperature
- Limp mode after the fault repeats
Likely causes
- Valve stuck off by varnish, sludge or a scored bore
- Broken or collapsed valve spring preventing normal stroke
- Hardened or split servo piston seals leaking apply pressure
- Low line pressure from low fluid, a worn pump or an internal leak
- Contaminated ATF and a clogged filter starving the servo circuit
- Faulty solenoid or an open circuit in the wiring that feeds this circuit
- Worn band or clutch pack that cannot hold once the servo does apply
How to fix it
- Check fluid level, colour and smell and look for band or clutch material on the magnet
- Log gear ratio against the commanded gear on live data to confirm which element slips
- Measure line and servo circuit pressure with a gauge and compare with specification
- Command the related solenoid with the scan tool and check circuit resistance
- Remove the valve body and confirm the servo and servo control valves slide freely
- Inspect the servo piston, bore and seals for wear, scoring and hardened rubber
- Replace worn seals or the valve body, and service the band or clutch pack if it is glazed