BDU pre-charge error
• If the battery system has been pre-charged to many times in a short while the pre-charge resistor might be over heated. Wait for 2 minutes for the resistor to cool down • Verify power supply to the BDU and/or check for DTCs in IBU for low supply voltage. • Check for DTC’s regarding the heater that might be the reason for pre-charge malfunction • Check VCB system for short circuits. • Check the VCB main fuse located in the maintenance disconnector mounted in the battery pack(E83). Measure the resistance if open load change the fuse and also the BDU according to instruction in Multi. • Dismount the battery pack (E83) according to instruction in multi • Control the connections between the IBU and BDU that they are connected properly. • Change IBU mounted in battery pack(E83) according instruction in Multi • Change BDU mounted in battery pack(E83) according instruction in Multi NOTE! Replacing the IBU and BDU are considered as electrical work and shall only be performed by Scania certified personnel. Vehicle shall be made safe according to electrical work procedure.
What you'll see
No driver-visible symptom recorded.
System reaction
• The hybrid system will go to error state. It is not possible to activate the battery pack (E83). • VOR, the hybrid system will not work since the battery will not be engaged. The DCC will not receive VCB-power and the 24-volt system will drain the 24-volt batteries. • Amber warning lamp "24V batteries not charged" and "Hybrid System Fault" is shown in ICL
Diagnostic depth
Precharge was not finished within 1 s or energy over precharge resistor exceeded 800 J.
• Heater is active during pre charge. • A short circuit make it impossible to charge the system. • BDU pre-charge circuit defective • BDU supply voltage is too low. • BMU voltage measurement, current measurement or pre-charge driver defective • Capacitance on DC-link is to high.