DTC P0780
DTC P0780: Shift Error
General Description
The transmission control module (TCM) monitors driving direction by comparing the driving direction detected from the dual speed sensor (input speed/output speed) and the driving direction calculated from the commanded current value of the pressure regulator. The TCM also monitors the conditions of each clutch and engagement/disengagement of the parking interlock gear. If the driving direction detected from the dual speed sensor (input speed/output speed) and the driving direction calculated from the commanded current value of the pressure regulator do not match, or if the clutch engagement combination of reverse driving is detected while forward driving, or if unintended engagement/disengagement of the parking interlock gear is detected, the TCM detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 1 second or more |
| DTC Type | One drive cycle, MIL on, A/T gear position indicator blinks |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| Transmission input speed [Transmission Input Speed]* | 200 rpm | - |
| Transmission output speed [Transmission Output Speed]* | 200 rpm | - |
| Vehicle speed [Vehicle Speed] when driven in forward*** | 19 mph (30 km/h) | - |
| Shift position*, ** | D, R | |
| Shift position***, **** | D | |
| Shift position***** | P | |
*: Symptom 1
**: Symptom 2
***: Symptom 3
****: Symptom 4
****: Symptom 5
[ ]: HDS Parameter
Malfunction Threshold
One of these symptoms occurs:
Symptom 1
- The detected speed directions of dual speed sensor (input speed) and dual speed sensor (output speed) is abnormal when driving in forward, and the detected speed directions of dual speed sensor (input speed) and dual speed sensor (output speed) matches when driving in reverse.
Symptom 2
- Clutch engagement combination of reverse driving (clutch B, D, and dog clutch F are engaged) is detected while the shift position is in D position/mode and clutch engagement combination of other than reverse driving (clutch B, D, and dog clutch F are engaged) is detected while the shift position is in R position/mode.
Symptom 3
- Clutch engagement combination of reverse driving (clutch B, D, and dog clutch F are engaged) is detected while the shift position is in D position/mode.
Symptom 4
- The parking lock actuator does not operate after a specified duration the shift position is selected to D position/mode.
Symptom 5
- The solenoid valve for the parking cylinder is activated when the shift position is selected to the P position/mode and the commanded current value of the pressure regulator to provide hydraulic pressure to the parking lock valve is more than a specified current for a specified duration.
Possible Cause
The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
- Hydraulic control unit internal failure
- TCM internal failure
Confirmation Procedure
Operating Condition
- 1.
Start the engine in P position/mode.
- 2.
Drive the vehicle at a speed of 19 mph (30 km/h) or more in D position/mode.
- 3.
Drive the vehicle in R position/mode.
- Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.
With the HDS
None.
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the A/T gear position indicator blinks, the MIL comes on, and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the TCM memory.
Conditions for clearing the DTC
The A/T gear position indicator comes off by turning the vehicle to the OFF (LOCK) mode. 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.