With Manufacturer's Scan Tool
Motronic Engine Control Module (ECM) Power Supply Relay -J271, checking
The Engine Control Module (ECM), ignition coils and valves for camshaft adjustment are powered via the ECM power supply relay, -J271.
The ECM power supply relay -J271 will be activated with the ignition on.
Test conditions
- Battery voltage OK
Checking activation of the ECM power supply relay
The ECM power supply relay is located in the electronics box in the front passenger's footwell, (relay panel, relay position 2).
- Switch ignition off.
- Connect VAG 1598/31 test box to wiring harness for engine control module. Do not connect to engine control module itself. Refer to Scan Tool Testing/Scan Tool Connecting and Initial Checks/Connecting VAG 1598/31 Test Box Connecting VAG 1598/31 Test Box
Specification: The ECM power supply relay should be activated.
If the relay is now activated but not while switching ignition on:
- Replace Engine Control Module (ECM)
If the relay does not activate:
- Check voltage supply for the ECM power supply relay
Checking voltage supply for ECM power supply relay
- Check fuse for ECM power supply relay -J271.
If the fuse is not faulty:
- Remove ECM power supply relay from the relay panel (relay position 2).
- Connect multimeter (voltage measurement range) between Ground (GND) and terminal 4 on relay panel.
Specification: approx. battery voltage
If the specification is not obtained:
- Check wiring
If the specification is obtained:
- Test for open circuit and short to B+ or Ground (GND) in the following wiring connection:
Micro central electrics VAG1598/31 test box
in box passenger's footwell Socket
(right), relay position 2
terminal
9 23
- Repair any open/short circuit as necessary.
If no malfunction is detected in the wire:
- Replace ECM Power Supply Relay -J271.
- Display readiness code Readiness Code Reading . Readiness code must be regenerated if DTC memory was erased. Readiness Code, Generating
Activating Cruise Control System (CCS)
- Connect Vehicle Diagnostic, Testing and Information System VAS 5051 or VAG 1551 Scan Tool and select engine electronics control module by entering address word "01". When doing this the ignition must be switched on. Scan Tool Testing/Scan Tool Connecting and Initial Checks/Connecting VAG 1551/ VAS 5051 Scan Tool
Indicated on display
Rapid data transfer HELP
Select function XX
- Press button -1- twice to select "Log-in procedure" function and confirm entry with -Q- button.
Indicated on display
Log-in procedure HELP
Input code number XXXXX
- Input code number 11463 and confirm entry with Q key.
- Select (for measure of control) "address word" 01 to select control module for engine control module.
Indicated on display
4D0907558..4.2L V8/5V GD.. ->
Coding 06752 WSC 06388
Specified value: "G"