DTC U0401:68 [i-ELOOP]

id130201001100

DTC U0401:68

Signal error from PCM

DETECTION CONDITION

•  When any of the following conditions is met:

―  PCM internal malfunction

―  CAN communication line malfunction between PCM and DC-DC converter (i-ELOOP)

FAIL-SAFE FUNCTION

•  Not applicable

POSSIBLE CAUSE

•  CAN drive error (DC-DC converter (i-ELOOP) or PCM)

•  CAN communication line malfunction between PCM and DC-DC converter (i-ELOOP)

―  PCM terminal 2AK—Front body control module (FBCM) terminal 2P

―  PCM terminal 2AL—Front body control module (FBCM) terminal 2N

―  Front body control module (FBCM) terminal 2K—DC-DC converter (i-ELOOP) terminal 1A

―  Front body control module (FBCM) terminal 2I—DC-DC converter (i-ELOOP) terminal 1C

•  Front body control module (FBCM) malfunction

•  DC-DC converter (i-ELOOP) connector or terminals malfunction

•  PCM connector or terminals malfunction

•  DC-DC converter (i-ELOOP) malfunction

•  PCM malfunction

DTC U0401:68	Signal error from PCM
DETECTION CONDITION	• When any of the following conditions is met: ― PCM internal malfunction ― CAN communication line malfunction between PCM and DC-DC converter (i-ELOOP)
FAIL-SAFE FUNCTION	• Not applicable
POSSIBLE CAUSE	• CAN drive error (DC-DC converter (i-ELOOP) or PCM) • CAN communication line malfunction between PCM and DC-DC converter (i-ELOOP) ― PCM terminal 2AK—Front body control module (FBCM) terminal 2P ― PCM terminal 2AL—Front body control module (FBCM) terminal 2N ― Front body control module (FBCM) terminal 2K—DC-DC converter (i-ELOOP) terminal 1A ― Front body control module (FBCM) terminal 2I—DC-DC converter (i-ELOOP) terminal 1C • Front body control module (FBCM) malfunction • DC-DC converter (i-ELOOP) connector or terminals malfunction • PCM connector or terminals malfunction • DC-DC converter (i-ELOOP) malfunction • PCM malfunction

Diagnostic Procedure

STEP	INSPECTION		ACTION
1	VERIFY RELATED SERVICE INFORMATION AVAILABILITY • Verify related Service Information availability. • Is any related Service Information available?	Yes	Perform repair or diagnosis according to the available Service Information. • If the vehicle is not repaired, go to the next step.
1		No	Go to the next step.
2	VERIFY PCM DTCs • Switch the ignition off, then ON (engine off). • Retrieve the PCM DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].) • Are any DTCs present?	Yes	Repair or replace the malfunctioning part according to the applicable DTC troubleshooting. (See DTC TABLE [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].)
2		No	Go to the next step.
3	CONFIRM FRONT BODY CONTROL MODULE (FBCM) DTC • Perform the front body control module (FBCM) DTC inspection using the M-MDS. (See DTC INSPECTION [FRONT BODY CONTROL MODULE (FBCM)].) • Are any DTCs present?	Yes	Repair or replace the malfunctioning part according to the applicable DTC troubleshooting. (See DTC TABLE [FRONT BODY CONTROL MODULE (FBCM)].)
3		No	Go to the next step.
4	CONFIRM INSTRUMENT CLUSTER DTC • Perform the instrument cluster DTC inspection using the M-MDS. (See DTC INSPECTION [INSTRUMENT CLUSTER].) • Are any DTCs present?	Yes	Repair or replace the malfunctioning part according to the applicable DTC troubleshooting. (See DTC TABLE [INSTRUMENT CLUSTER].)
4		No	Go to the next step.
5	INSPECT DC-DC CONVERTER (i-ELOOP) CONNECTOR CONDITION • Switch the ignition off. • Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].) • Remove the service plug. (See SERVICE PLUG DISCONNECTION/CONNECTION [i-ELOOP].) • Disconnect the DC-DC converter (i-ELOOP) connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion). • Is there any malfunction?	Yes	Repair or replace the connector and/or terminals, then go to Step 7.
5		No	Go to the next step.
6	INSPECT PCM CONNECTOR CONDITION • Disconnect the PCM connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion). • Is there any malfunction?	Yes	Repair or replace the connector and/or terminals, then go to the next step.
6		No	CAN communication line can be considered the cause. • Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals: ― PCM terminal 2AK—Front body control module (FBCM) terminal 2P ― PCM terminal 2AL—Front body control module (FBCM) terminal 2N ― Front body control module (FBCM) terminal 2K—DC-DC converter (i-ELOOP) terminal 1A ― Front body control module (FBCM) terminal 2I—DC-DC converter (i-ELOOP) terminal 1C If there is a common connector: ― Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a malfunction. ― Repair or replace the malfunctioning part. If there is no common connector: ― Repair or replace the wiring harness. If the malfunction recurs, replace the DC-DC converter (i-ELOOP). (See DC-DC CONVERTER (i-ELOOP) REMOVAL/INSTALLATION [i-ELOOP].) Go to the next step.
7	VERIFY DTC TROUBLESHOOTING COMPLETED • Always reconnect all disconnected connectors. • Reinstall the service plug. (See SERVICE PLUG DISCONNECTION/CONNECTION [i-ELOOP].) • Reconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].) • Clear the DTC for the DC-DC converter (i-ELOOP) using the M-MDS. (See CLEARING DTC [i-ELOOP].) • Switch the ignition off. • Switch the ignition ON (engine on) and wait for 5 s or more. • Retrieve the DC-DC converter (i-ELOOP) DTCs using the M-MDS. (See DTC INSPECTION [i-ELOOP].) • Is the same DTC present?	Yes	Repeat the inspection from Step 1. • If the malfunction recurs, replace the PCM. (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].) Go to the next step.
7		No	Go to the next step.
8	VERIFY IF OTHER DTCs DISPLAYED • Are any other DTCs displayed?	Yes	Repair or replace the malfunctioning part according to the applicable DTC troubleshooting. (See DTC TABLE [i-ELOOP].)
8		No	DTC troubleshooting completed.