Applies to: BMU6 (RES)BMU6 (RESXA)BMU6 (RESXB)BMU6 (RESXC)BMU6 (RESXD)BMU6 (RESXE)BMU6 (RESXF)BMU6 (RESXG)BMU6 (RESXH)BMU6 (RESXI)BMU6 (RESXJ)BMU6 (RESXK)
What does Scania BMU fault code 639 mean?
Too much deviation in the propulsion battery's internal power supply.
What causes Scania DTC 639?
- Internal fault in the propulsion battery. See related fault codes in IBU system. - Fault in T282, UI sensor in battery junction box.
How does the system react?
- The contactors in the propulsion battery are opened. - Risk of VOR. - The electric drive system stops working because the propulsion battery is not available. - Direct current converter E84 (DCC) is not supplied with voltage class B and the 24 V system will drain the 24 V batteries.
What are the symptoms?
Propulsion battery not supplying any power. If the vehicle has multiple propulsion batteries: - The contactors cannot be closed on the relevant propulsion battery. - The vehicle's total battery capacity and range are reduced. If the vehicle has only one propulsion battery: - VOR. - Electric drive of the vehicle is not possible. - The vehicle's 24 V voltage is turned off. - No charge is possible.
How to fix Scania BMU fault code 639?
- Troubleshoot and action any fault codes in the IBU control unit.
- Check that the fault code has been actioned by turning the key voltage off and on.
- Renew T282, UI sensor in battery junction box.
This information is for guidance only. Always follow the manufacturer workshop manual and safety procedures; if in doubt, contact an authorised workshop.