Troubleshooting and Testing Requirements
Electrical testing
^ If the On Board Diagnostic (OBD) does not give any indication of the source of the malfunction, work through the complete Electrical testing.
^ If the On Board Diagnostic (OBD) provides a direct indication of the source of the malfunction, only carry out the test steps recommended in the DTC table (specific testing).
Requirements for test
^ An Automatic test sequence must first be performed to establish that any malfunctions present in the transmission and engine control modules can only originate from the ABS/EDL.
- Connect VAG 1551 scan tool and select address word 00 with ignition switched on.
- After completing the Electrical testing, interrogate and erase the DTC memories of the transmission and engine control modules.
- The multi-pin connector between the wiring harness and ABS control module (w/EDL) -J104- must be in proper condition, without bent, broken or corroded contacts. Replace any damaged contacts using VAS 1978 wiring repair kit.
Note: The instructions supplied with VAS 1978 wiring repair kit normally do not permit repairs to the wiring of the ABS and its associated systems. However, this only applies to the screened wiring in the systems.
^ Switch ignition and electrical consumers off before commencing the check (headlights, lighting, fan, etc.).
Test equipment required:
^ VAG 1598 test box
^ VAG 1598/27 adapter
^ VAG 1594 auxiliary test set
^ VAG 1526 tester hand-held multimeter
Connecting VAG 1598 test box with VAG 1598/27 adapter:
- Switch off ignition.
- Connect VAG 1598/27 adapter to VAG 1598 test box. Pull multi-pin connector off ABS control module (w/EDL) -J104-, and connect VAG 1598/27 adapter and VAG 1598 test box to connector on ABS/EDL wiring harness.
The socket designations on VAG 1598 test box are identical with the contact designations on ABS control module (w/EDL) -J104- and on the wiring harness connector
Contact assignment of multi-pin connector on wiring harness for ABS control module (w/EDL) -J104-.
Note: All contacts not listed are currently not assigned and must not be connected to other components.
Notes: Regarding test table:
^ The socket designations of the VAG 1598 test box are identical to the contact designations of the ABS control module (w/EDL) -J104- in the wiring diagram. Incorrect test procedures can cause damage to the system: do not make connections between any contacts other than those listed in the table
^ The specified values refer to the readings obtained on VAG 1526 tester and are not necessarily applicable for other test units.
^ If the readings obtained do not match the specifications, carry out malfunction repair measures in the right-hand part of the table.
^ If the specified values are achieved, also check wiring for intermittent loose contacts and short circuit to positive and Ground (GND). This applies especially to sporadic malfunctions.
^ Use only VAG 1594 auxiliary test set for checking continuity (bridging leads).
^ If the measured figures only differ slightly from the specifications, clean the sockets and plugs of the testers and adapter leads (with contact spray G 000 700 04) and repeat the check. Before replacing components, check the wiring and connections again, particularly if the specification calls for a resistance reading of less than 10 Ohms.