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

id0902p2010600

Description

Error signal received from PCM
Detection condition
•  Front body control module (FBCM) receives the error engine coolant temperature (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
Not applicable
Possible cause
•  DTCs are stored in the PCM.
•  Engine coolant temperature (ECT) sensor malfunction
•  Ambient temperature sensor malfunction
•  PCM malfunction
•  Front body control module (FBCM) malfunction
System wiring diagram
Not applicable

Diagnostic Procedure

Step

Inspection

Action
1
VERIFY FRONT BODY CONTROL MODULE (FBCM) DTCs AGAIN
•  Clear the DTC for the front body control module (FBCM) using the M-MDS.
•  Switch the ignition ON (engine off or on) and wait for 5 s or more.
•  Retrieve the front body control module (FBCM) DTCs using the M-MDS.
•  Is the same DTC displayed?
Yes
Go to the next step.
No
Go to Step 7.
2
VERIFY PCM DTCs
•  Retrieve the PCM DTCs using the M-MDS.
•  Are any DTCs displayed?
Yes
Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
(See DTC TABLE [PCM (SKYACTIV-G 2.5T)].)
No
Go to the next step.
3
INSPECT ENGINE COOLANT TEMPERATURE (ECT) SENSOR
•  Inspect the engine coolant temperature (ECT) sensor.
•  Is the engine coolant temperature (ECT) sensor normal?
Yes
Go to the next step.
No
Replace the engine coolant temperature (ECT) sensor, then go to Step 6.
(See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].)
4
INSPECT AMBIENT TEMPERATURE SENSOR
•  Inspect the 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 6.
(See AMBIENT TEMPERATURE SENSOR REMOVAL/INSTALLATION.)
5
VERIFY IF MALFUNCTIONING LOCATION IS PCM DEPENDING ON REPEATABILITY
•  Clear the DTC for the front body control module (FBCM) using the M-MDS.
•  Switch the ignition ON (engine off or on) and wait for 5 s or more.
•  Retrieve the front body control module (FBCM) DTCs using the M-MDS.
•  Is the same DTC displayed?
Yes
Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].)
No
Go to Step 7.
6
VERIFY THAT REPAIRS HAVE BEEN COMPLETED
•  Clear the DTC for the front body control module (FBCM) using the M-MDS.
•  Switch the ignition ON (engine off or on) and wait for 5 s or more.
•  Retrieve the front body control module (FBCM) DTCs using the M-MDS.
•  Is the same DTC displayed?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the front body control module (FBCM).
Go to the next step.
No
Go to the next step.
7
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 [FRONT BODY CONTROL MODULE (FBCM)].)
No
DTC troubleshooting completed.