Troubleshooting

Troubleshooting BCM-U040482

Checking diagnostic trouble codes in the central electronic module (CEM)
If there are any diagnostic trouble codes stored in the central electronic module (CEM) for communication errors or the back-up lights, perform troubleshooting of these first.

Were any diagnostic trouble codes stored in the central electronic module (CEM) for communication errors or the back-up lights?

Yes - DONE

No - Information

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Information

Note! If the back-up lights are on with reverse gear engaged and off in other positions, the function is okay. This indicates that the control module has previously registered a malfunction, but the malfunction no longer exists.

Vehicle with manual transmission
In vehicles with manual transmission, there is a reverse gear switch on the transmission. The switch closes and gives a directly connected signal to the central electronic module (CEM) when reverse gear is engaged. This signal is then sent from the transmission control module (TCM) via the CAN-net to the brake control module (BCM). Check the function of the reverse gear switch. See wiring diagram.

Vehicle with automatic transmission
In vehicles with automatic transmission a signal is sent from the transmission control module (TCM) via the CAN-net to the central electronic module (CEM) that reverse gear is selected. This signal is also sent from the transmission control module (TCM) via the CAN-net to the brake control module (BCM). Check the function in the automatic transmission and lever carrier.
Remedy as necessary.

Other information
- Checking wiring and terminals Checking Wiring and Terminals

Continue - DONE

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