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Home >> Mazda >> 2019 >> CX-9 Signature >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Communication Devices >> On-Board Diagnostic - Front Body Control Module (FBCM) >> DTC U0401-68: Error Signal Received From Pcm [Front Body Control Module (FBCM)] >> Diagnostic Procedure
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Diagnostic Procedure

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

Step Inspection Action
1 VERIFY FRONT BODY CONTROL MODULE (FBCM) DTCs AGAIN  Yes Go to the next step.
No Go to Step 7.
2 VERIFY PCM DTCs  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  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  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  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 Yes Repeat the inspection from Step 1.
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.