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
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.
•  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.
•  Is DTC U0401:68 displayed?
Yes
Go to the next step.
No
Go to Step 6.
2
INSPECT ECT SENSOR
•  Is the ECT sensor normal?
Yes
Go to the next step.
No
Replace the ECT sensor, then go to Step 5.
3
INSPECT AMBIENT TEMPERATURE SENSOR
•  Is the ambient temperature sensor normal?
Yes
Go to the next step.
No
Replace the ambient temperature sensor, then go to Step 5.
4
PERFORM DTC INSPECTION AND VERIFY IF MALFUNCTIONING PART IS PCM
•  Clear front body control module (FBCM) DTCs using the M-MDS.
•  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.
•  Is DTC U0401:68 displayed?
Yes
Replace the PCM, then go to the next step.
No
Go to Step 6.
5
VERIFY THAT REPAIRS HAVE BEEN COMPLETED
•  Clear front body control module (FBCM) DTCs using the M-MDS.
•  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.
•  Is DTC U0401:68 displayed?
Yes
replace the front body control module (FBCM), then go to the next step.
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.
No
DTC troubleshooting completed.