Scan Tool Connecting

Wiring and Components, Checking with Test Box VAG 1598/42

Special tools, testers and auxiliary items required

• Adapter (V.A.G 1598/39-1)

• Adapter (V.A.G 1598/39-2)

• Test Box 105 Pin (V.A.G 1598/42)

• The test box is designed with 105 pins. The connection cable can be separated from the test box. This means that as new engine control module (ECM) connectors are introduced in the future, only a new cable must be designed and no longer the entire test box.

• The smaller of the two connectors on the ECM is assigned with terminals 1 to 60. The larger of the two connectors is assigned with terminals 1 to 94.

• For testing at the 60-pin harness connection, the (V.A.G 1598/39-1) is connected to the test box with connector - A -. Components of the 60-pin harness connection.

• For testing at the 94-pin harness connection, the (V.A.G 1598/39-2) is connected to the test box with connectors - A - and - B -. Components of the 94-pin harness connection.





• The (V.A.G 1598/42) is designed so that it can be connected simultaneously to the engine control module harness and the engine control module itself.

• This is advantageous because electronic engine control remains fully functional (for example measurement of signals with engine running) when the test box is attached.

• Always use connector test set (V.A.G 1594 C) to connect measuring equipment (for example voltage tester (V.A.G 1527 B), portable multimeter (V.A.G 1526 C), etc.)

• The procedures will indicate whether the engine control module is to remain connected to the test box or not.


To avoid damaging electronic components, switch to the corresponding measuring range and observe all test conditions before connecting the test leads.

The engine control module (ECM) must be removed to disconnect the ECM multi-pin connectors. Refer to => [ Engine Control Module ] Service and Repair.

- Connect (V.A.G 1598/42) to wiring harness connector. Ground (GND) clip at test box must be clipped to battery minus. The procedures will indicate whether the engine control module is to be connected to the test box.

- Perform test as described in relevant repair sequences.

Installing engine control module

Install in reverse order of removal.

- Thereafter, the engine control module must be equipped with the metal retainer.

- Clean threaded holes for shear bolts of locking compound residue. Cleaning can be performed with a thread cutter (tap).

- Always use new shear bolts.

- Check the DTC memory and, if necessary, erase.