DTC Advanced Diagnostics: U0131 (1.5L Engine, PGM-FI System)
DTC U0131: PF-CAN Malfunction (Powertrain Control Module (PCM)-EPS Control Unit)
General Description
The controller area network (CAN) transmits/receives pulsing signals to/from the control modules simultaneously by using two signal lines (F-CAN_H and F-CAN_L). When the information is not sent from the electrical power steering (EPS) control unit via the F-CAN lines and this condition continues for a specified time or when the information sent from the EPS control 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 | 1.5 seconds or more |
| DTC Type | One drive cycle, MIL off |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| Elapsed time after the vehicle condition is turned to the ON mode | 3 seconds | - |
| 12 volt battery voltage [Battery] | 10.0 V | - |
[ ]: HDS Parameter
Malfunction Threshold
One of these conditions is met:
- The PCM cannot receive any signals from the EPS control unit via the F-CAN lines for at least 1.5 seconds.
- The information sent from the EPS control unit is abnormal at least 20 times.
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.
- PF-CAN circuit PF-CAN A_H line open
- PF-CAN circuit PF-CAN A_L line open
- PF-CAN circuit PF-CAN A_H line short to ground
- PF-CAN circuit PF-CAN A_L line short to ground
- PF-CAN circuit PF-CAN B_H line open
- PF-CAN circuit PF-CAN B_L line open
- PF-CAN circuit PF-CAN B_H line short to ground
- PF-CAN circuit PF-CAN B_L line short to ground
- VF-CAN circuit VF-CAN C_H line open
- VF-CAN circuit VF-CAN C_L line open
- VF-CAN circuit VF-CAN C_H line short to ground
- VF-CAN circuit VF-CAN C_L line short to ground
- EPS control unit failure (include fuse fall-outs)
- PCM internal circuit failure
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, a Pending DTC, a Confirmed DTC, the freeze data, and the on-board snapshot are stored in the PCM memory. The MIL does not come on.
Conditions for clearing the DTC
The Pending DTC, the Confirmed DTC, the freeze data, and the on-board snapshot can be cleared with the scan tool clear command.