Advanced Diagnostics

DTC P0977: Open in Shift Solenoid Valve B Circuit




General Description
When shift solenoid valves A and D are turned ON, the hydraulic pressure circuit Opens. When shift solenoid valves B and C are turned OFF, the hydraulic pressure circuit Opens. The hydraulic pressure circuit supplies/discharges hydraulic pressure to/from each clutch according to the combination of the ON/OFF status of those valves and the shift valves. The powertrain control module (PCM) commands the driver circuit to turn on the shift solenoid valve. The circuit diagnoses malfunctions such as a circuit short or Open, and sends back a return signal during the PCM's command. A malfunction is detected when the return signal does not match the PCM command to turn OFF the shift solenoid valve, and a DTC is stored.




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




Enable Conditions

Malfunction Threshold
The return signal does not match the command to turn OFF shift solenoid valve B for at least 1 second.

Driving Pattern
Start the engine, drive the vehicle so that it shifts from 1st to 4th gear in the D position, then drive the vehicle in 3rd or 4th gear for at least 1 second.

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

Diagnosis Details

Conditions for illuminating the MIL
When a malfunction is detected, the MIL comes on and the DTC and the freeze frame data are stored in the PCM memory.

Conditions for clearing the MIL
The MIL will be cleared if the malfunction does not recur during three consecutive trips in which the diagnostic runs.

The MIL, the DTC, and the freeze frame data can be cleared by using the scan tool Clear command or by disconnecting the battery.