Fault-Tracing Information

Fault-tracing

Checking the power supply and ground terminal




- Ignition off.
Check the cable for voltage feed between the battery monitoring module (BMS) and the battery's positive terminal with regard to open circuit and short circuit to ground.
Check the signal cable between the battery monitoring module (BMS) and the central electronic module (CEM) with regard to intermittent short circuit to ground, intermittent open circuit as well as contact resistance and oxidation.
Remedy the cables as necessary.

Other information
- Connecting the breakout box For Connection of Breakout Box to Central Electronic Module (CEM)
- Checking wiring and terminals Checking Wiring and Terminals. Permanent Faults
- Battery Monitoring Sensor, B6304T4 Service and Repair





Was a fault detected?

Yes - Verification

No - Checking communication

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Checking communication




- Ignition on.
Check the communication with the battery monitoring module (BMS) by clicking the VCT2000 symbol.
If the readout indicates that the communication is OK, despite the diagnostic trouble code CEM-B11DB87 being stored, then this means that the fault is intermittent. If the diagnostic trouble code's counter indicates that the fault has been stored many times then the battery monitoring module (BMS) should be replaced.

Note! It takes approx. 10 seconds after the engine has been started before the fault in the communication with the control module for the battery monitoring module (BMS) is detected.





Is communication established?

Yes - FAULT FOUND

No - Replacing the control module

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Replacing the control module




- Ignition off.
If no fault was detected on the cables to the control module then the battery monitoring module (BMS) probably needs to be replaced.

Other information
- Battery Monitoring Sensor, B6304T4 Service and Repair

Continue - Verification

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Verification




- Ignition off
- Reconnect cables and switches
- Ignition on.
Check the communication with the battery monitoring module (BMS) by clicking the VCT2000 symbol.





Is communication established?

Yes - FAULT FOUND

No - Fault-tracing information

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Fault-tracing information

Attempt New Test - Checking the power supply and ground terminal

FAULT-TRACING FAILED - No Fault Found

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