DTC Advanced Diagnostics: U0146 (PGM-FI System (3.5L Engine)) (2025)
DTC U0146 : PF-CAN Malfunction (Powertrain Control Module (PCM)-CAN Gateway)
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 CAN gateway via the F-CAN lines and this condition continues for a specified time or when the information sent from the CAN gateway 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 second or more |
| DTC Type | One drive cycle, MIL on |
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 does not receive any signals from the CAN gateway via the F-CAN lines for at least 1 second.
- The information sent from the CAN gateway 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 C_H line open
- PF-CAN circuit PF-CAN C_L line open
- PF-CAN circuit PF-CAN C_H line short to ground
- PF-CAN circuit PF-CAN C_L line short to ground
- CAN gateway failure (include fuse fall-outs)
- 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, the freeze data, and the on-board snapshot are stored in the PCM memory.
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.