Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC Advanced Diagnostics: U0104 (PGM-FI System (3.0L Engine)) (2025)
DTC U0104 : PF-CAN Malfunction (Powertrain Control Module (PCM)-Driving Support System 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). If the powertrain control module (PCM) does not receive any signals from the multipurpose camera unit via the F-CAN lines or if the information sent from the multipurpose camera unit is abnormal, the 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 V | - |
[ ]: HDS Parameter
Malfunction Threshold
One of these conditions is met:
- The PCM does not receive any signals from the multipurpose camera unit via the F-CAN lines for at least 1.5 seconds.
- The information sent from the multipurpose camera 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 A_H line short to power
- PF-CAN circuit PF-CAN A_L line short to power
- PF-CAN circuit PF-CAN A_H line short to PF-CAN circuit PF-CAN A_L line
- 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
- PF-CAN circuit PF-CAN C_H line short to power
- PF-CAN circuit PF-CAN C_L line short to power
- PF-CAN circuit PF-CAN C_H line short to PF-CAN circuit PF-CAN C_L line
- AF-CAN circuit AF-CAN A_H line open
- AF-CAN circuit AF-CAN A_L line open
- AF-CAN circuit AF-CAN A_H line short to ground
- AF-CAN circuit AF-CAN A_L line short to ground
- AF-CAN circuit AF-CAN A_H line short to power
- AF-CAN circuit AF-CAN A_L line short to power
- AF-CAN circuit AF-CAN A_H line short to AF-CAN circuit AF-CAN A_L line
- CAN gateway failure
- Multipurpose camera 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.
NO RELATED
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.