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Home >> Audi >> 1999 >> A4 Base, 1.8 B, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing >> Fuel System >> Fuel Pump Relay >> A4 (1.8L Turbo) Fuel Pump Relay Signal
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A4 (1.8L Turbo) Fuel Pump Relay Signal

  1. Fuel pump relay is located in position No. 6 of relay panel located under left side of instrument panel. See Figure . Remove fuel pump relay.
  2. Remove cover from end of left side of dashboard. Remove fuses No. 28, 29 and 34. Connect VAG 1527B voltage tester between fuel pump relay connector terminals No. 28 and 29. Voltage tester should dimly light. Briefly crank starter. Voltage tester should continue to dimly light. If voltage tester does not light as specified, go to next step. If voltage tester lights as specified, fuel pump relay signal is okay. Test is complete.
  3. Turn ignition off. Disconnect Powertrain Control Module (PCM) connectors. Connect VAG 1598/22 test box to PCM wiring harness.
  4. Connect DVOM to test box socket 4 and fuel pump relay connector terminal No. 29. Resistance should be a maximum of one ohm. If resistance is within specification, go to next step. If resistance is not within specification, repair wiring harness as necessary. See WIRING DIAGRAMS article. Test is complete.
  5. If wiring is okay, but voltage tester does not light, replace Powertrain Control Module (PCM). If wiring is okay and fuel pump relay signal is okay, replace fuel pump relay.
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