Audi A8 1994 - Page 75

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Control unit Faults entered in fault memory
2 - No message from control unit 1
- No message from control unit 3
3 - No message from control unit 2
- Switch off ignition.
- Disconnect control units linked by bus wires and examine bus wires for open circuit.
=> Current Flow Diagrams, Electrical Fault-finding and Fitting Locations binder
- Replace control unit 2 if no faults are found in bus wires.
Example 3:
Faults entered in fault memory reveal that none of the control units can transmit or receive.
Control unit Faults entered in fault memory
1 - e.g. Drive train data bus defective
2 - e.g. Drive train data bus defective
3 - e.g. Drive train data bus defective
- Switch off ignition.
- -> Disconnect control units linked by bus wires and examine bus wires for mutual shorting.
=> Current Flow Diagrams, Electrical Fault-finding and Fitting Locations binder
- -> Examine bus wires for short to positive/earth.
=> Current Flow Diagrams, Electrical Fault-finding and Fitting Locations binder
Audi A8 1994 ➤
Electrical system Self-diagnosis 02.99 ➤ - Edition 05.2002
1.18 - Checking data exchange between control units 71