Advanced Diagnostics

DTC P1744 (45) Advanced Diagnostics

DTC P1744:

Problem in Shift Control System; Shift Valve E Stuck ON










Hydraulic pressure supply to the clutch by shift solenoid valve output (D position)





General Description

Shift valve E is in the control circuit of the transmission. It is controlled by pressure from shift solenoid valve B, and it is locked by the line pressure. It switches off when shift solenoid valve B turns off and shift solenoid valve A turns on. The powertrain control module (PCM) monitors the input shaft (mainshaft) speed and the output shaft (countershaft) speed at the gear change determined by the shift schedule. When an improper gear ratio output is compared to the predetermined gear change mode, the PCM detects a shift valve E ON failure and stores a DTC.

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





Enable Conditions





Malfunction Threshold

- The transmission is held in 5th gear against the 1st gear shift command for at least 1.5 seconds.
- After driving the vehicle in 3rd gear with D for at least 1.5 seconds.

Driving Pattern

1. Start the engine.
2. Accelerate the vehicle until the transmission shifts into 5th gear in D.

- 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.