DTC U0081 (131) (Battery Condition Monitor Module A)
DTC U0081 (131): EP-CAN 2 Malfunction (Battery Condition Monitor Module A Bus-Off)
General Description
The controller area network (CAN) transmits/receives pulsing signals to/from the control modules simultaneously by using two signal lines (EPP-CAN B_H and EPP-CAN B_L). If the bus-off occurs due to an open or a short circuit in the EPP-CAN line is detected for a prescribed time, the battery control processor in the battery condition monitor module A detects a malfunction and a DTC is stored.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 2.5 seconds or more |
| DTC Type | One drive cycle, MIL on, POWER SYSTEM indicator on, 12 volt battery charging system indicator off |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| Elapsed time since the 12 volt battery voltage reaches to a specified value after the vehicle condition is turned to the ON mode | 50 milliseconds | - |
| 12 volt battery voltage | 10.2 V | - |
Malfunction Threshold
The EPP-CAN line bus-off continues for at least 2.5 seconds.
Possible Cause
- EPP-CAN circuit EPP-CAN B_H line short to ground
- EPP-CAN circuit EPP-CAN B_L line short to ground
- Unit communicating on EPP-CAN B internal circuit failure
- Battery condition monitor module A module failure
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the MIL and the POWER SYSTEM indicator comes on and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the battery condition monitor module A memory.
Conditions for clearing the DTC
The MIL and the POWER SYSTEM indicator are cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL and the POWER SYSTEM indicator, 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.