S6 V8-4.2L (BBD) (2004)
Main Relay (Computer/Fuel System): Testing and Inspection
With Manufacturer's Scan Tool
Motronic Engine Control Module (ECM) power supply relay -J271-, checking
NOTE: The Motronic Engine Control Module (ECM) power supply relay -J271- is located in a triple relay carrier in electronic box in plenum chamber,
relay position 3.
Check actuation of ECM power supply relay
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Switch ignition off.
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Remove Motronic Engine Control Module (ECM) power supply relay - J271- from triple relay carrier.
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Connect test box VAG 1598/31 to wiring harness for engine control module; do not connect engine control. See: Testing and Inspection/Scan Tool
Testing and Procedures/Scan Tool Testing/With Manufacturer's Scan Tool/Scan Tool Connecting and Initial Checks/Connecting VAG 1598/31
Test Box
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Check following wiring for an open circuit or short circuit
Test box V.A.G
1598/31, socket
Power supply relay, contact
23
4
Wire resistance: max. 1.5 Ohm
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Correct any open/short circuit as necessary.
If no wiring malfunction is detected:
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Check power supply for power supply relay.
Check the power supply
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Switch ignition off.
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Connect hand-held multimeter to contact 2 and 9 of relay socket and Ground to measure voltage.
Specified value: approx. battery voltage
If the specified value is not achieved, test the supply voltage according to the wiring diagram.
If the specified value is achieved, check the wiring connections between power supply relay and engine control module.
Checking wiring between power supply relay and engine control module
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Check fuse (see wiring diagram)
If no malfunction is detected at the fuse.
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Check following wiring for an open circuit or short circuit
Test box V.A.G
1598/31, socket
Power supply relay, contact
3
Wire resistance: max. 1.5 Ohm