Pinout Values and Diagnostic Parameters

Electrical Checks Using VAG 1598 Test Box

REQUIREMENTS
- Battery voltage OK.
- Fuses 18 and 21 OK.
- Ground connections on engine and transmission OK (engine ground connection: on support for upper intake manifold).
- Fuel pump and fuel pump relay OK.




CONNECTION
- Switch ignition OFF.
- Disconnect harness connector from Motronic Engine Control Module.

Caution! Ignition must be switched OFF before disconnecting engine control module. After switching OFF ignition, allow 20 seconds for the hot wire in the Mass Air Flow (MAF) sensor to heat up and self clean.

- Connect adaptor cable VAG 1598/18 between the Test Box and engine control module harness connector.
- The ECM is left disconnected.

Note:
- On vehicles with automatic transmissions, performing electrical checks will generate and store malfunctions in the Diagnostic Trouble Code (DTC) memory, which must be erased. See DTC Memory.
- Some test steps included in the following charts are for components that are not on all vehicles, i.e. EGR Sensor, Air Pump relay, etc.

- Perform the electrical checks using the VAG 1598 Test charts.

Test Steps 1-5:

Test Steps 6-7:

Test Steps 8-11:

Test Steps 12-19:

Test Steps 20-22:

Test Steps 23-24:

Test Steps 25-27:

Test Steps 28-30:

Test Steps 31-35: