90S Quattro (Canada) V6-2.8L (AAH) (1993)
-
Switch ignition on.
Central Electric Panel With Detail Of Relay Position 6
-
Connect multimeter (Fluke 83 or equivalent) to measure voltage at fuel pump relay panel sockets:
^
Sockets 28 (positive) and 34
^
Sockets 32 (B+) and 34 Specified value: approx. 12 volts
-
Switch ignition off.
If the specified values are not obtained:
-
Eliminate open circuits in wiring using wiring diagram.
Checking activation of fuel pump relay
-
Connect US 1115 LED tester or equivalent to relay sockets 28 and 29.
^
Ignition on: LED must light up brightly for approx. 1 sec., then stay dimly lit
^
Starter operated: LED must become visibly brighter
If LED lights up dimly when ignition is switched on but does not get brighter when starter is operated:
-
Replace Engine Control Module (ECM).
If LED tester does not light up, check wiring as follows:
-
Connect VAG 1598 test box to ECM wiring harness using VAG 1598/12 adaptor harness. The numbers of the connectors are identical to those
on the test box.
-
Connect multimeter (Fluke 83 or equivalent) between relay socket 29 and test box socket 15 and check for open circuit.
Specified reading: maximum 1 (ohm)
If specified reading is not obtained:
-
Eliminate open circuit in wiring using wiring diagram. If there is no open circuit and LED tester does not light up:
-
Replace ECM.
If activation of fuel pump relay and wiring are both OK:
-
Replace fuel pump relay -J17-.
-
Replace fuse no. 17 and both circuit breakers again.