90S Quattro (Canada) V6-2.8L (AAH) (1993)
Engine Control Module: Component Tests and General Diagnostics
Checking ECM voltage supply
NOTE:
To check the ECM voltage supply also refer to On Board Diagnostic, "Read Measuring Value Block" function 08, display group 001, display field
4.
Requirements
^
Circuit breaker -S64- must be OK (yellow holder in electronic box in passenger side footwell).
Test Procedure
-
Connect VAG 1598 test box with VAG 1598/12 adapter harness to ECM wiring harness. See: Powertrain Management/Computers and Control
Systems/Testing and Inspection/Scan Tool Testing and Procedures/Scan Tool Testing/Scan Tool Connecting and Initial Checks/Connecting VAG
1598/31 Test Box
^
Adapter harness is not connected to ECM.
-
Switch ignition on.
-
Connect US 1115 LED Tester or equivalent between test box socket 8 (B+ via ignition) and Ground (GND).
^
LED must light up
If LED does NOT light up:
-
Check for break in wiring according to wiring diagram and repair if necessary.
-
Connect LED Tester to test box socket 8 (B+ supply via ignition) and successively to sockets 1,2,3 and 16 (Ground connections).
^
LED must light up in each case
If LED does not light up:
-
Check wiring between intake manifold GND point and connector -D- using wiring diagram.
ECM Harness Connectors
Test box socket
ECM connector D
terminal
1
1
2
2
3
3
16
16
-
Switch ignition off.
-
Connect VAG 1598 test box with VAG 1598/11 adapter harness to ECM wiring harness.
^
Adapter harness is not connected to ECM.
-
Connect VAG 15278 voltage tester between test box socket 40 (permanent 8+) and Ground (GND).
^
LED must light up.
If LED does NOT light up:
-
Check wiring connection between ECM connector -8- terminal 20 and central electric panel according to wiring diagram.