DTC U0291
DTC U0291: EPP-CAN Malfunction (Powertrain Control Module (PCM)-Park Pawl Actuator Driver Unit)
General Description
The electric power plant-controller area network (EPP-CAN) transmits/receives pulsing signals to/from the control modules simultaneously by using two signal lines (EPP-CAN A_H and EPP-CAN A_L). When the information is not sent from the park pawl actuator driver unit via the EPP-CAN lines and this condition continues for a specified time or when the information sent from the park pawl actuator driver unit is abnormal and this condition continues for a specified cycle, the powertrain control module (PCM) detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 200 milliseconds or more |
| DTC Type | One drive cycle, MIL on |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| 12 volt battery voltage [Battery] | 10.0 V | - |
| Elapsed time after the vehicle condition is turned to the ON mode | 3 seconds | - |
[ ]: HDS Parameter
Malfunction Threshold
One of these conditions is met:
- The PCM does not receive any signals via the EPP-CAN lines for at least 200 milliseconds.
- The information sent from the park pawl actuator driver unit is abnormal at least 20 times.
Possible Cause
- Park pawl actuator driver unit failure (include fuse fall-outs)
- EPP-CAN circuit EPP-CAN A_H line open
- EPP-CAN circuit EPP-CAN A_L line open
- EPP-CAN circuit EPP-CAN A_H line short to ground
- EPP-CAN circuit EPP-CAN A_L line short to ground
- PCM internal circuit failure
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 12 volt battery.