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C70, S70 & V70

  1. Turn ignition off. Remove fuse No. 2. Connect ammeter between fuse No. 2 terminals. Turn ignition on. Using scan tool, activate fuel pump. If amperage is 4-5 amps, fuel pump is okay. If amperage is not 4-5 amps, go to next step.
  2. Turn ignition off. Leave ammeter connected to fuse No. 2 terminals. Remove fuse/relay unit cover. Remove fuel pump relay at position No. 103. Turn ignition on. Connect jumper wire between relay connector terminals No. 1 and 3. See Figure. If amperage is not 4-5 amps, go to next step. If amperage is 4-5 amps, go to step  6.
  3. Reinstall fuse No. 2. Turn ignition on. Connect voltmeter between fuel pump relay terminals No. 1 and ground. See Figure. Turn ignition on. If voltmeter reads battery voltage, go to next step. If voltmeter does not read battery voltage, check fuses and wiring.
  4. Turn ignition off. Disconnect 2-pin fuel pump connector in trunk. Connect ohmmeter between relay side of fuel pump connector terminal No. 2 and ground. See Figure. If about zero ohms are present, go to next step. If about zero ohms are not present, check connector terminals for poor terminal contact.
  5. Connect ohmmeter between fuel pump side of fuel pump connector terminals No. 1 and 2. See Figure. If about 0.5-2 ohms are present, check wiring between fuel pump relay terminals No. 1 and 3 for an open circuit.
  6. Turn ignition off. Ensure fuel pump relay is disconnected. Connect ohmmeter between relay base terminal No. 2 and ground. If about zero ohms are present, go to next step. If about zero ohms are not present, check for terminal contact in relay ground circuit. If relay ground circuit is okay, check wiring between fuel pump relay terminal No. 2 and ground.
  7. Turn ignition on. Ensure fuel pump relay is disconnected. Connect voltmeter between relay base terminal No. 4 and ground. If about 4-5 volts are present, go to next step. If greater than about 4-5 volts are present, check wiring between relay terminal No. 4 and ECM terminal B27 for a short circuit to ground. If less than about 4-5 volts are present, disconnect ECM. Connect ohmmeter between relay base terminal No. 4 and ground. If infinite resistance is present, check for open circuit in wiring between fuel pump relay terminal No. 4 and ECM connector terminal B27. If infinite resistance is not present, check for short circuit in wiring between relay base terminal No. 4 and ECM connector terminal B27.
  8. Turn ignition off. Reinstall fuel pump relay. Reconnect ECM and fuel pump. Attempt to start engine. If engine does not start, replace fuel pump relay. If engine does start, problem was poor contact in ECM, fuel pump, or fuel pump relay connection.
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