DTC Advanced Diagnostics: U0128 (1.5 L Engine)

DTC Advanced Diagnostics: U0128

DTC U0128:F-CAN Malfunction (Powertrain Control Module (PCM)-Electric Parking Brake Control Unit)

General Description

The controller area network (CAN) transmits/receives pulsing signals to/from the control modules simultaneously by using F-CAN A and B signal lines. When the powertrain control module (PCM) does not receive the signals from the electric brake booster via the F-CAN lines for a set time, the 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 off

Enable Conditions

Condition	Minimum	Maximum
12 volt 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 second.

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 A_H line short to ground
	F-CAN circuit F-CAN A_L line short to ground
	F-CAN circuit F-CAN A_H line open
	F-CAN circuit F-CAN A_L line open
	F-CAN circuit F-CAN B_H line short to ground
	F-CAN circuit F-CAN B_L line short to ground
	F-CAN circuit F-CAN B_H line open
	F-CAN circuit F-CAN B_L line open
	Electric parking brake 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 or by disconnecting the 12 volt battery.