B-2: Fuel Injector Circuit Inspection: Aerio
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, check each fuel injector for operating "clicking" sound as engine is cranked or running. See Figure . If any one or all fuel injectors do not make operating sound, go to next step. If all fuel injectors made operating sound, fuel injector circuit is okay.
- Turn ignition switch to LOCK position. Disconnect suspect fuel injector(s) 2-pin harness connector(s). See Fig 1 . Check fuel injector(s) harness connector(s) for poor, loose corroded or damaged connector terminals. If connector and terminals are okay, go to next step. If connector or terminals are faulty, repair or replace as necessary. After repair, retest system for normal operation.
- Using DVOM, measure continuity between all fuel injectors connector terminals No. 1 and 2 and fuel injector body (component side). If continuity is not found, go to next step. If continuity is found, replace fuel injector. See FUEL RAILS & INJECTORS underFUEL SYSTEM in REMOVAL & INSTALLATION article. After repair, retest system for normal operation.
- Turn ignition switch to ON position. Using DVOM, measure voltage between ground and fuel injector(s) harness connector terminal No. 2 (Blue/Black 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 for open or short circuit in Blue/Back wire between fuel injector and main relay. After repair, retest system for normal operation.
- Turn ignition switch to LOCK position. Disconnect ECM 28-pin harness connector C46. ECM is located under instrument panel, behind glove box. See Fig 2
. Using DVOM, measure resistance between ground specified ECM connector terminal. See CHECKING CIRCUITS BETWEEN FUEL INJECTOR & ECM
table. 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 faulty circuit for short to ground between fuel injector and ECM. After repair, retest system for normal operation.CHECKING CIRCUITS BETWEEN FUEL INJECTOR & ECM
ECM Connector Terminal No. Wire Color C46 20 (Blue/Yellow) C46 8 (Blue/White) C46 1 (Blue/Red) C46 2 (Blue/Green) - Turn ignition switch to ON position. Using DVOM, measure voltage between ground and specified ECM connector terminal. See CHECKING CIRCUITS BETWEEN FUEL INJECTOR & ECM table. See Fig 3 . See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If voltage is zero volts, go to next step. If any voltage is found, repair appropriate faulty circuit for short to power between fuel injector and ECM. After repair, retest system for normal operation.
- Turn ignition switch to LOCK position. Connect ECM and all fuel injector connectors. Turn ignition switch to ON position. Backprobe and measure voltage between ground and specified ECM connector terminal. See CHECKING CIRCUITS BETWEEN FUEL INJECTOR & ECM table. See Fig 3 . See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If voltage is 10-14 volts, perform fuel injector component test. See FUEL INJECTORS under FUEL SYSTEM in SYSTEM & COMPONENT TESTING article. If any fuel injector is faulty, replace as necessary. If fuel injectors are okay, substitute ECM with known good module. See ENGINE CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. If voltage is less than 10 volts, repair open circuit at appropriate wire between fuel injector and ECM. After repair, retest system for normal operation.