Cable and Components, Checking With the Test Box 105 Pin (V.A.G 1598/42)

Cable and Components, Checking with the Test Box 105 Pin (V.A.G 1598/42)

Special tools, testers and auxiliary items required

• Adapter Cable (V.A.G 1598/39-1)

• Adapter Cable (V.A.G 1598/39-2)

• Test Box 105 Pin (V.A.G 1598/42)

• The test box has 105 terminals. 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".

• 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 -.

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

• The procedures will indicate whether the ECM 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.

- Remove the ECM. Refer to => [ Engine Control Module (J623) ] Engine Control Module.

- Connect (V.A.G 1598/42) to wiring harness with (V.A.G 1598/39-1) or (V.A.G 1598/39-2). Clamp test box Ground (GND) clip to battery negative terminal. The procedure will indicate whether the ECM is to be connected to the test box or not.

- Perform test as described in relevant repair sequences.

Installing the ECM

Installation is performed in reverse order, ECM must be installed with the protective housing. New shear bolts must be used.

- Check the Diagnostic Trouble Code (DTC) memory and erase if necessary. Use a vehicle diagnostic tester.

• When ending Guided Fault Finding, the tester attempts to erase the DTC memory of all control modules. If this is not successful, the remaining DTCs stored in memory must be corrected until all DTCs can be erased.