DTC U0100(ACM System)

DTC U0100: F-CAN Malfunction (ACM-PCM)

General Description

Courtesy of HONDA, U.S.A., INC.

The controller area network (CAN) transmits/receives pulsing signals to/from the control modules simultaneously by using two signal lines (H line and L line). When the information is not sent from the powertrain control module (PCM) via the F-CAN lines and this condition continues for a specified time or when the information sent from the PCM is abnormal and this condition continues for a specified cycle, the engine mount control unit detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type

Execution	Continuous
Sequence	None
Duration	4.0 seconds or more
DTC Type	One drive cycle, MIL off

Enable Conditions

Condition	Minimum	Maximum
Elapsed time since the 12 volt battery voltage reaches to a specified value 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 engine mount control unit does not receive any signals via the F-CAN lines for at least 4.0 seconds.
The information sent from the PCM is abnormal at least 20 times.

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 B_H line open
F-CAN circuit F-CAN B_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 short to F-CAN circuit F-CAN B_L line
Engine mount control unit internal circuit 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. 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 12 volt battery.