B-3: Fuel Pump Circuit Inspection: Aerio
CAUTION:
Ensure jumper connections are made correctly. Improper connections may result in damage to PCM and wire harness.
NOTE:
Perform all voltage and resistance tests using a Digital Volt-Ohm Meter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Use ohmmeter to isolate wiring harness shorts or opens.
- Using a mechanic's stethoscope at gas tank, check for fuel pump operation sound when ignition switch is turned ON. If fuel pump operation sound is heard for 3 second and stop, circuit is in good condition. If fuel pump is not heard, go to next step.
- Turn ignition switch to LOCK position. Disconnect fuel pump relay from relay/fuse box, located in engine compartment. See Figure . Ensure is proper connection at each terminal of fuel pump relay, repair as necessary. Turn ignition switch to ON position. Measure voltage between ground and fuel pump relay/fuse box connector C07 terminals No. 2 and 3 (Black/Red wire). See Fig 1 . See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If voltage is 10-14 volts, go to next step. If voltage is less than 10 volts, check power and ground circuit to ECM. If ECM power and ground circuit are okay, repair open or short circuit to ground in Black/Red wire between ECM and fuel pump relay. After repair, retest system for normal operation.
- Perform fuel pump relay component test. See RELAYS under RELAYS & SOLENOIDS in SYSTEM & COMPONENT TESTING article. If fuel pump relay is okay, go to next step. If fuel pump relay is faulty, replace relay. After repair, retest system for normal operation.
- Turn ignition to LOCK position. Disconnect engine harness connector G01 to instrument panel harness connector C42, located under right side of dash panel. Check for proper connection at Gray/Blue wire terminals, between connectors G01 and C42. Connect fuel pump relay to relay/fuse box. Connect DVOM between ground and ECM harness connector G04 terminal 12(Gray/Blue wire). See Fig 2 . See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Measure voltage 3 seconds after ignition switch is turned to ON position. if voltage is 10-14 volts, go to next step. If voltage is 10 volts or less, repair open circuit or short to ground in Gray/Blue wire between ECM and fuel pump relay. After repair, retest system for normal operation.
- Within 3 seconds of turning ignition switch to ON position. Measure voltage between ground and ECM harness connector G04 terminals 12 (Gray/Blue wire). See Fig 2 . See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If voltage is 0-1 volt, go to next step. If voltage is more than one volt, substitute ECM with known good module. See ENGINE CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article.After repair, retest system for normal operation.
- Turn ignition switch to LOCK position. Detach fuel tank. See FUEL TANK & FUEL PUMP under FUEL SYSTEM in REMOVAL & INSTALLATION article. Disconnect fuel pump 4-pin harness connector L50, located on fuel tank. Measure resistance between ground and fuel pump harness connector L50 terminal No. 3 (Pink wire). See Fig 3 . See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If resistance is infinity, go to next step. If any resistance is found, repair short to ground in Pink wire between fuel pump and fuel pump relay. After repair, retest system for normal operation.
- Ensure ignition switch is in LOCK position. Connect a fused jumper wire between ground and ECM harness connector G04 terminals No. 12 (Gray/Blue wire). See Fig 2 . Turn ignition switch to ON position. Measure voltage between ground and fuel pump connector L50 terminal No. 3 (Pink wire). See Fig 3 . See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If voltage is 10-14 volts, go to next step. If voltage is less than 10 volts, repair open circuit in Pink wire between fuel pump and fuel pump relay. After repair, retest system for normal operation.
- Turn ignition switch to LOCK position. Check for continuity between fuel pump harness connector L50 terminals No. 4 (Black wire). See Fig 3 . See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Turn ignition switch to LOCK position. If continuity is found, replace faulty fuel pump. See FUEL TANK & FUEL PUMP under FUEL SYSTEM in REMOVAL & INSTALLATION article. If continuity is not found, repair open circuit in Black wire, between fuel pump relay and ground point 15, 17 or 20. After repair, retest system for normal operation.