Checking Instructions/Can Data Bus
Checking instructions/CAN data busDiagnostic conditions
- Ignition on
- Internal control module function test
Possible cause of fault
1. No data can be sent/received via CAN data bus (CAN data bus OFF):
One of the following errors is memorised in all control modules: CAN drive (high/low)/ CAN infotainment (high/low)/ CAN comfort OFF (high/low)
Use the table 'Cause of fault 1' for troubleshooting.
- Short circuit to B+
- Short circuit to ground
- Short circuit with respect to each other ('high' and 'low' wires)
- Confused 'high' and 'low' wires (wrong slot in connector, or faulty wires confused during repairs)
2. Expected control module message missing/no communication possible with control module:
Read out the fault memory in the gateway and localise the error via the memorised error using the CAN topology. --> 9; Rep. Gr. 97; Circuit diagram
Use the table 'Cause of fault 2' for troubleshooting.
- The corresponding control module does not have a power/ ground supply
- The corresponding control module does not function
- CAN data bus on affected control module interrupted
Affected pins
The measurements to be taken are listed in the work instruction below. The measurements must be implemented using the 'pin assignment' shown in the table below, while taking the relevant 'control module' and 'CAN data bus' into account.
Diagnosis/troubleshooting, CAN data bus
NOTE: Faults can only be located quickly and effectively with the help of the 'CAN topology' and 'CAN networking'. --> 9; Rep. Gr. 97; Circuit diagram
Cause of error '1', no data can be sent/received via CAN data bus (CAN data bus OFF):
Cause of error '2', expected control module message missing/no communication possible with control module:
NOTE:
- Before replacing the control module, the ground connections, power supply and plug connections on the control module must be checked.
- When replacing the control unit, observe the coding.
- After the test drive, read out the fault memory with the 9588 Porsche System Tester II again. Additional causes of faults that could damage the control module should be detected and remedied.
