DTC U0401:68 [FRONT BODY CONTROL MODULE (FBCM)]

id0902p2010600

System malfunction location

Error signal received from PCM

Detection condition

•  The front body control module (FBCM) receives error ECT sensor or ambient temperature sensor signals from the PCM for 5 s or more with the ignition switched ON (engine off or on).

Fail-safe

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Possible cause

•  ECT sensor malfunction

•  Ambient temperature sensor malfunction

•  PCM malfunction

•  Front body control module (FBCM) malfunction

System wiring diagram

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System malfunction location	Error signal received from PCM
Detection condition	• The front body control module (FBCM) receives error ECT sensor or ambient temperature sensor signals from the PCM for 5 s or more with the ignition switched ON (engine off or on).
Fail-safe	—
Possible cause	• ECT sensor malfunction • Ambient temperature sensor malfunction • PCM malfunction • Front body control module (FBCM) malfunction
System wiring diagram	—

Diagnostic Procedure

Step	Inspection		Action
1	VERIFY FRONT BODY CONTROL MODULE (FBCM) DTCs AGAIN • Clear front body control module (FBCM) DTCs using the M-MDS. (See CLEARING DTC [FRONT BODY CONTROL MODULE (FBCM)].) • Switch the ignition ON (engine off or on) and wait for 5 s or more. • Perform the front body control module (FBCM) DTC inspection using the M-MDS. (See DTC INSPECTION [FRONT BODY CONTROL MODULE (FBCM)].) • Is DTC U0401:68 displayed?	Yes	Go to the next step.
1		No	Go to Step 6.
2	INSPECT ECT SENSOR • Inspect the ECT sensor. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5].) (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [SKYACTIV-D 2.2].) • Is the ECT sensor normal?	Yes	Go to the next step.
2		No	Replace the ECT sensor, then go to Step 5. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION [SKYACTIV-G 2.0, SKYACTIV-G 2.5].) (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION [SKYACTIV-D 2.2].)
3	INSPECT AMBIENT TEMPERATURE SENSOR • Inspect the ambient temperature sensor. (See AMBIENT TEMPERATURE SENSOR INSPECTION [MANUAL AIR CONDITIONER].) (See AMBIENT TEMPERATURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER].) • Is the ambient temperature sensor normal?	Yes	Go to the next step.
3		No	Replace the ambient temperature sensor, then go to Step 5. (See AMBIENT TEMPERATURE SENSOR REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER].) (See AMBIENT TEMPERATURE SENSOR REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)
4	PERFORM DTC INSPECTION AND VERIFY IF MALFUNCTIONING PART IS PCM • Clear front body control module (FBCM) DTCs using the M-MDS. (See CLEARING DTC [FRONT BODY CONTROL MODULE (FBCM)].) • Switch the ignition ON (engine off or on) and wait for 5 s or more. • Perform the front body control module (FBCM) DTC inspection using the M-MDS. (See DTC INSPECTION [FRONT BODY CONTROL MODULE (FBCM)].) • Is DTC U0401:68 displayed?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.0, SKYACTIV-G 2.5].) (See PCM REMOVAL/INSTALLATION [SKYACTIV-D 2.2].)
4		No	Go to Step 6.
5	VERIFY THAT REPAIRS HAVE BEEN COMPLETED • Clear front body control module (FBCM) DTCs using the M-MDS. (See CLEARING DTC [FRONT BODY CONTROL MODULE (FBCM)].) • Switch the ignition ON (engine off or on) and wait for 5 s or more. • Perform the front body control module (FBCM) DTC inspection using the M-MDS. (See DTC INSPECTION [FRONT BODY CONTROL MODULE (FBCM)].) • Is DTC U0401:68 displayed?	Yes	replace the front body control module (FBCM), then go to the next step. (See FRONT BODY CONTROL MODULE (FBCM) REMOVAL/INSTALLATION.)
5		No	Go to the next step.
6	VERIFY IF OTHER DTCs DISPLAYED • Are any other DTCs displayed?	Yes	Repair the malfunctioning part according to the applicable DTC troubleshooting. (See DTC TABLE [FRONT BODY CONTROL MODULE (FBCM)].)
6		No	DTC troubleshooting completed.