S90 & V90
- Turn ignition off. Remove fuse No. 1 from central electrical unit located in left side of engine compartment. See Fig 1. Turn ignition on. Lightly squeeze hose connected to fuel pressure regulator and reinstall fuse. If fuel pump operates for a few seconds after fuse is reinstalled, fuel pump is okay. Check ignition system. See IGNITION CHECKS . If fuel pump does not operate, go to next step.
Courtesy of VOLVO CARS OF NORTH AMERICA.
- Access fuse/relay box on left side of instrument panel. Remove fuel pump relay from position No. 2. Connect jumper wire between relay base terminals No. 1 and 3. See Figure. Turn ignition on. Lightly squeeze hose connected to fuel pressure regulator and reinstall fuse. If fuel pump operates for a few seconds after fuse is reinstalled, go to step 6). If fuel pump does not operate, go to next step.
- Turn ignition off. Ensure fuel pump relay is removed. Turn ignition on. Connect voltmeter between relay base terminal No. 1 and ground. See Figure. If battery voltage is present, go to next step. If battery voltage is not present, check fuse No. 4. If fuse is okay, check voltage supply to fuse. Repair as necessary.
- Turn ignition off. Disconnect fuel pump 4-pin connector located in luggage compartment. Connect ohmmeter between relay side of fuel pump connector terminal No. 4 and ground. See Fig 2. If about zero ohms are present, go to next step. If about zero ohms are not present, check fuel pump connector terminals and ground at left seat support for poor terminal contact. Repair as necessary. Repeat resistance check. If reading is now okay, source of fault was poor terminal contact. If reading is still not okay, check for open circuit in wiring between fuel pump connector terminal No. 4 and ground, and at ground connection at left seat support. Repair as necessary.
Courtesy of VOLVO CARS OF NORTH AMERICA.
- Connect ohmmeter between fuel pump connector terminals No. 1 and 4. See Fig 2. If about 0.5-2 ohms are present, check wiring between fuel pump relay terminal No. 3 and fuel pump terminal No. 1 for an open circuit. If about 0.5-2 ohms are not present, replace fuel pump.
- Ensure ignition is on and fuel pump relay is removed. Connect voltmeter between relay base terminal No. 4 and ground. See Figure. If about 2-5 volts are present, go to next step. If more than a bout 5 volts are present, check wiring between fuel pump relay terminal No. 4 and ECM terminal A40 for a short circuit to voltage. If less than 2 volts are present, turn ignition off. Connect ohmmeter between relay base terminal No. 4 and ground. If infinite resistance is present, check wiring between fuel pump relay terminal No. 4 and ECM terminal A40 for an open circuit. If infinite resistance is not present, check wiring between fuel pump relay terminal No. 4 and ECM terminal A40 for a short circuit to ground.
- Ensure ignition is off. Reinstall fuel pump relay. Reconnect fuel pump connector. Attempt to start engine. If engine starts, cause of fault was poor contact in fuel pump relay or fuel pump connectors. Repair as necessary. If engine does not start, replace fuel pump relay.