No Fuel Pressure
- Check fuel pump fuse and replace if defective. If fuse is okay, pull off electrical connector on fuel pump. Connect volt/ohmmeter between the 2 wires in connector and start engine. Volt/ohmmeter should read battery voltage. If voltage is correct, replace fuel pump.
- If voltage reading is incorrect, check ground (Brown) wire: Connect volt/ohmmeter between wire and ground. Resistance should be 0. If not, repair wire. If resistance is correct, check power (Green/Violet) wire: Disconnect Relay 1 and connect volt/ohmmeter between power wire and connector 87 of relay socket. Resistance should be 0. If value is incorrect, repair wire.
- If resistance is correct, check power supply from Relay 1: Connect volt/ohmmeter between wire 30 (Green/Yellow) on relay socket and ground. Turn ignition on. Meter should read battery voltage. If not, repair wire.
- If voltage is correct, check power supply to Relay 1: Connect volt/ohmmeter between wire 86 (Red/White) of plug and ground. Start engine. Volt/ohmmeter should show battery voltage. If not, connect a volt/ohmmeter between wire 87 (Red/White) of Relay 2 and ground (relay still connected). Turn on ignition. Voltmeter should read battery voltage. If reading is incorrect, repair wire.
- If power supply to Relay 1 is correct, check Relay 1 ground: Connect volt/ohmmeter between wire 85 (Brown/Green) on socket and ground. Start engine. Resistance should be about 0. If resistance is correct, replace Relay 1.
- If voltage in last part of step 4) is correct, or if resistance is incorrect in step 5), check resistance of Brown/Green wire between connector 85 on Relay 1 plug and pin 20 of MCU connector. Resistance should be 0. If not, repair wire. If resistance is correct, go to Test 3 for Motronic Control Unit.