DTC P1220: Fuel Pump Control Module (FPCM)
- Check Power Supply - Turn ignition off. Disconnect FPCM harness connector. See Fig 1. Disconnect fuel pump harness connector, located behind inspect ion cover under rear seat. Using a voltmeter, measure voltage between FPCM connector terminal No. 3 (Black/Yellow wire) and ground. Also, measure voltage between fuel pump connector terminal No. 1 (Black/Yellow wire) and ground. If battery voltage exists, go to next step. If battery voltage does not exist, check for blown fuse No. 32 or fault in Black/Yellow wire.
- Check Ground Circuit - Leave ignition off. Disconnect dropping resistor harness connector. Check continuity between dropping resistor connector terminal No. 2 (Black wire) and ground. Also, check continuity between FPCM harness connector terminal No. 2 (Black wire) and ground. If continuity exists, go to next step. If no continuity exists, repair fault in Black wire and retest system.
- Check continuity as follows:
- Between dropping resistor harness connector terminal No. 1 (Green/Red wire) and fuel pump harness connector terminal No. 2 (Green/Red wire).
- Between dropping resistor harness connector terminal No. 1 and FPCM connector terminal No. 1 (Green/Red wire).
- Between ground and fuel pump harness connector terminal No. 2 (Green/Red wire).
- Between ground and FPCM connector terminal No. 1 (Green/Red wire).
If continuity exists, go to next step. If continuity does not exists, repair fault in Green/Red wire.
- Check Output Signal Circuit - Turn ignition off. Disconnect ECM harness connector. Using an ohmmeter, check continuity between ECM harness connector terminal No. 15 and FPCM harness connector terminal No. 4 (Black/Pink wire). If no continuity exists, repair open in Black/Pink wire. If continuity exists, go to next step.
- Check Input Signal Circuit
- Using an ohmmeter, check continuity as follows:
- Between ECM harness connector terminal No. 28 and FPCM harness connector terminal No. 1 (Green/Red wire).
- Between ECM harness connector terminal No. 28 and fuel pump harness connector terminal No. 2 (Green/Red wire).
- Between ECM harness connector terminal No. 28 (Green/Red wire) and ground.
If continuity exists, repair short to ground in Green/Red wire. If continuity does not exist, go to next step.
- Check Dropping Resistor - Disconnect dropping resistor harness connector. Measure resistance between connector terminals. See Fig 2. If resistance is about 0.9 ohms at 77°F (25°C), go to next step. If resistance is not about 0.9 ohms at 77°F (25°C), replace dropping resistor.
- Check FPCM - Start engine and warm to operating temperature. Turn ignition off and wait at least 5 seconds. Start engine and allow to idle. Measure voltage between FPCM connector terminals 1 and 2. See Fig 3. Voltage should zero volts within 30 seconds of starting engine and about 3.7 volts after 30 seconds of starting engine. If voltage is not as specified, replace FPCM. If voltage is as specified, disconnect and reconnect harness connectors in circuit. Check ECM pin terminals for damage or corrosion. Repair if necessary and retest.