B-2: Fuel Injector Circuit Inspection: Vitara
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 all fuel injectors made operating sound, go to next step. If any one or all fuel injectors do not make operating sound, go to step 3 .
- Turn ignition switch to LOCK position, Disconnect ECM harness connectors C51-2 and C51-3. ECM is located under instrument panel, behind glove box. See Figure
. Using DVOM, measure resistance at specified circuit between ECM connector terminals. See CHECKING FUEL INJECTOR CIRCUIT RESISTANCE
table. See Fig 1
-Fig 2
. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Resistance should be 13-16 ohms at 20 °C (68 °F). If resistance is as specified, fuel injector circuit is okay. If resistance is not as specified, repair short between fuel injectors circuit wires, between fuel injector and ECM. After repair, retest system for normal operation.CHECKING FUEL INJECTOR CIRCUIT RESISTANCE
ECM Connector/Terminal (Wire Color) ECM Connector/Terminal (Wire Color) C51-2/2 (Pink) C51-3/4 (Blue/Black) C51-2/1 (Pink/Black) C51-3/4 (Blue/Black) C51-2/9 (Pink/Green) C51-3/4 (Blue/Black) C51-2/8 (Gray/Blue) C51-3/4 (Blue/Black) - If all fuel injectors do not make operating sound, go to next step. If any fuel injector does not make operating sound, check fuel injector(s) harness connector(s) for poor, loose corroded or damaged connector terminals. If connectors and terminals are okay, perform fuel injector component test. See FUEL INJECTORS under FUEL SYSTEM in SYSTEM & COMPONENT TESTING article. If connectors and terminals are faulty, repair or replace as necessary. After repair, retest system for normal operation.
- Disconnect all fuel injectors 2-pin harness connector. Using DVOM, measure voltage at all fuel injector connectors terminals No. 2 (Blue/Black wire). 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 voltage is less than 10 volts, repair open or short circuit in Blue/Black wire between appropriate fuel injector and main relay. After repair, retest system for normal operation.