Customer statement/workshop statement:
– Display in the instrument cluster: “Second battery low”.
– Camper control unit: Indicates implausible, rapid discharge of the auxiliary battery(ies).
Notes:
– TPI only applies if the auxiliary battery(ies) is/are sufficiently charged.
– If the battery is flat, this TPI is not applicable.
Technical background:
– Problem: External chargers or directly connected inverters lead to incorrect displays, as the battery manager module does not recognize the charge.
– Solution: Inverters and chargers must be connected to suitable earth points.
Measures:
1. point out to the customer that the negative cable must be connected correctly.
2. update the software on the customer-specific function control unit (J608) to version 0503.
– Update improves the detection of the state of charge by the energy management system.
3. after the update: readjust the additional batteries.
– Enter incorrect Ah value, save, change ignition, enter correct Ah value.
