Advanced Diagnostics

Advanced Diagnostics

DTC P1745: Problem in Shift Control System; Servo Control Valve Stuck OFF or Servo Valve Stuck OFF









General Description
The servo control valve and the servo valve are part of the control circuit of the transmission. The valves operate when the shift lever is in D or S due to line pressure, and they turn off when the shift lever is in P, R, or N. The PCM monitors the mainshaft speed and the countershaft speed at the gear change determined by the shift schedule. When an improper gear ratio is output compared to the predetermined gear change mode, a servo control valve OFF or servo valve OFF failure is detected and a DTC is stored.

Monitor Execution, Sequence, Duration, DTC Type, OBD Status






Enable Conditions






Malfunction Threshold
One of Symptom 1 or Symptom 2 occurs:






Driving Pattern
Start the engine, and accelerate the vehicle until the transmission shifts into 5th gear.

- Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.

Diagnosis Details

Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, a Confirmed DTC and the freeze data are stored. The MIL does not come on.

Conditions for clearing the DTC
The Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the battery.