DTC P0979
DTC P0979: Shift Solenoid Valve C (Short)
General Description
Hydraulic pressure supply to the clutch by shift solenoid valve output
| Neutral-1st | 1st | Neutral- Reverse |
Reverse | |
|---|---|---|---|---|
| Shift solenoid valve A | ON | ON | ON | OFF |
| Shift solenoid valve B | OFF | ON | OFF | OFF |
| Shift solenoid valve C | OFF | OFF | ON | ON |
| 1st clutch | CPCD | LINE | - | - |
| 4th clutch | - | - | CPCD | LINE |
| Lock-up ON | |
|---|---|
| Shift solenoid valve A | ON/OFF |
| Shift solenoid valve B | ON/OFF |
| Shift solenoid valve C | ON |
| Torque converter clutch | CPCD |
LINE : Line pressure
CPCD: A/T clutch pressure control solenoid valve D pressure
When shift solenoid valves A, B, and C are turned ON, 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 the shift solenoid valves. The powertrain control module (PCM) commands the driver circuit to turn on the shift solenoid valve. The circuit detects malfunctions such as a circuit short or open, and sends back a return signal during the PCM's command. When the return signal does not match the PCM command to turn ON the shift solenoid valve, the PCM detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type, OBD Status
| Execution | Continuous |
| Sequence | None |
| Duration | 1 second or more |
| DTC Type | One drive cycle, MIL on, A/T gear position indicator blinks |
| OBD Status | PASSED/FAILED/NOT COMPLETED (STILL TESTING) |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| Battery voltage [BATTERY VOLTAGE] |
11 V | - |
| No active DTCs set (prevents monitor from running) | P0962, P0963, P0973, P0974, P0980, P2720, P2721 | |
[ ]: HDS Parameter
Malfunction Threshold
The return signal does not match the command to turn ON shift solenoid valve C [A/T SHIFT SOL VLV. C] for at least 1 second.
Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
- Shift solenoid valve C SHC line short to ground
- Shift solenoid valve C internal circuit short
- Shift solenoid valve C power supply line open
- Shift solenoid valve C power supply line short to ground
- PCM internal circuit failure
Confirmation Procedure
Operating Condition
- 1.
Start the engine.
- 2.
Shift to P, and wait for at least 1 second.
With the HDS
None.
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the PCM memory.
Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the battery.