A8 Sedan V8-3.7L (AEW) (1997)
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Connect VAG1527B LED voltage tester between relay terminals 28 (B+) and 29 (Ground from ECM).
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LED must light up for approx. 1 second and then go out.
When operating starter, LED must light up continuously.
NOTE: LED voltage testers with little current draw do not completely go out after 1 second, but will continue to glow dimly until the starter motor is
operated.
If LED does not light up, check wiring as follows:
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Connect VAG1598/19 test box to Engine Control Module (ECM) harness connector. Refer "Scan Tool Testing/Scan Tool Connecting and Initial
Checks/VAG1598/19 Test Box, Connecting" See: Powertrain Management/Computers and Control Systems/Testing and Inspection
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Connect multimeter US 1119 (Fluke 83 or equivalent) and check for continuity between relay terminal 29 and test box socket A4.
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If there is no continuity:
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Check wiring for open or short circuit.
If there is no open circuit, and LED does not light up:
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Replace Engine Control Module (ECM), and generate new readiness code. Refer to "Monitors, Trips and/or Drive Cycle (Readiness
Code)/Generating, Readiness Code" See: Powertrain Management/Computers and Control Systems/Testing and Inspection
If wiring harness and actuation of fuel pump relay are OK:
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Replace fuel pump relay.