Troubleshooting procedure

Troubleshooting is possible only if the fault is actually present. This means that targeted troubleshooting according to instructions (diagnosis/troubleshooting for the individual DTCs) is only possible if the entry has the status present in the fault memory.

If the fault is not present at the moment, it is necessary to check the following:

• Has the fault healing counter and possibly the fault erasing counter been decremented? This would indicate that the fault has been corrected
• Did the fault occur a long time ago? Read out the extended fault memory (operating time and mileage for last fault entry)
• Are the diagnostic conditions fulfilled? Carry out a short test or test drive, if necessary
• Are all the plug connections and ground points of the current path in question OK?
• By pulling and shaking, put all wiring harnesses of the current path in question in a state corresponding to that of driving operation (loose contact).
• Condition/leak-tightness of the catalytic converter
• For tank system: condition/leak-tightness of hoses and possibly the tank cap