With Manufacturer's Scan Tool

Control module power supply, checking

Check requirements:
- Fuse for engine control module OK
- Battery voltage at least 11 V
- Alternator OK
- Connect Vehicle Diagnostic, Testing and Information System VAS 5051 or V.A.G 1551 Scan Tool and select engine electronics control module 1 with "Address word" 01. For this purpose, engine must be running at idle speed.
Connecting VAS 5051 Scan Tool


Indicated on display


Rapid data transfer HELP
Select function XX


- Press keys 0 and 8 for function "Read measured value block" and confirm entry with Q key.

Indicated on display


Read measured value block 08
Enter display group number XXX


- Press keys 0, 0 and 4 for "display group number 4" and confirm entry with Q key.

Indicated on display


Read measured value block 4 ->
1 2 3 4


- Check specified value for battery voltage in display zone 2:

Display Group 4:

Evaluation of display group 4

Display Zone 2:

Checking voltage supply from terminal 15 and terminal 30

- Connect test box VAG 1598/31 to wiring harness for engine control module; do not connect engine control module. Connecting VAG 1598/31 Test Box
- Connect hand- held multimeter VAG 1526 (voltage range) to following sockets on test box.

Voltage supply terminal 15 with ignition on







Voltage supply terminal 30 with ignition off

Socket Specified value
1 (Ground) +62 (positive) approx. battery voltage
2 (Ground) +62 (positive) approx. battery voltage

If the specified values are not obtained:
- Check wiring connections.