DTC Advanced Diagnostics: U129E
DTC U129E:F-CAN Malfunction (Powertrain Control Module (PCM)-Power Control Unit (PCU)) (Engine Type: K24W1)

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 powertrain control module (PCM) does not receive the signals from the keyless access control unit via the F-CAN lines for a set time, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type, OBD Status
Execution
Continuous
Sequence
None
Duration
1.5 seconds or more
DTC Type
One drive cycle, MIL off
OBD Status
PASSED/FAILED/NOT COMPLETED (STILL TESTING)

Enable Conditions
Condition
Minimum
Maximum
Battery voltage [BATTERY]
10.0 V
–
[ ]: HDS Parameter

Malfunction Threshold
The PCM does not receive any signals via the F-CAN lines for at least 1.5 seconds.

Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
F-CAN circuit F-CAN_H line open
F-CAN circuit F-CAN_L line open
F-CAN circuit F-CAN_H line short to ground
F-CAN circuit F-CAN_L line short to ground
Keyless access control unit failure
PCM internal circuit failure

Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, a Pending DTC, a Confirmed DTC, and the freeze data are stored in the PCM memory. The MIL does not come on.

Conditions for clearing the DTC
The Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the battery.