In Technical Product Information 2023230/33, Volkswagen describes a fault pattern that can occur in the Grand California with a classic 12-volt starter battery. The focus is on a discharged or defective starter battery, which leads to starting problems and numerous subsequent faults in the vehicle.
Problem description
According to the TPI, a discharged or damaged starter battery can lead to
- the engine does not start
- the engine starts poorly
- Driving behavior complaints occur
In addition, error entries are stored in several control units that indicate an undervoltage in the 12-volt electrical system.
Typical error entries
The following entries may occur in the event log:
- Energy management warning
- No communication with battery monitoring
- General undervoltage faults in various control units
Errors may also be stored in the engine control unit that are not the technical cause but are caused by the undervoltage, for example:
- Exhaust gas recirculation error
- Boost pressure error
- Error relating to the differential pressure sensor of the particulate filter
These entries can falsely give the impression of a problem in the exhaust or charging system.
Technical background according to VW
Volkswagen cites the following possible causes:
- Battery maintenance not carried out on stationary or stock vehicles
- Maintenance or service work on 12 V components without subsequent testing
- Increased quiescent currents due to external consumers or third-party installations
- Deep discharge or defect in the starter battery
The TPI does not apply to vehicles with a 12 volt LiFePo starter battery.
Classification for the Grand California
This fault pattern is particularly relevant for the Grand California, as
- longer downtimes are typical
- the vehicle is frequently used seasonally
- additional consumers are present in the camping operation
A weak starter battery can therefore cause a large number of error messages, even though there is no actual fault in the affected systems.
Procedure according to TPI
Volkswagen provides in this case:
- Checking the condition of the starter battery
- Evaluation of the battery via diagnostics or battery test
- Replacement of the battery if a defect is detected
- Deleting the fault memory after replacing the battery
Only when the battery is deemed to be in order are further tests on the vehicle electrical system carried out.
