Diagnosis & Repair
- Inspect spark plug and check for spark at misfiring cylinder. See BASIC TESTING article. Repair as necessary. If spark plug is okay and spark is present, go to next step.
- Access ECM behind bottom center of instrument panel, in front of console. Turn ignition on. Using DVOM, backprobe ECM connector. Measure voltage between ground and injector terminals at ECM E5 connector. See IDENTIFYING INJECTOR TERMINALS table. See Figure. If voltage is 9-14 volts for each circuit, go to step 4). If voltage is not 9-14 volts, go to next step.IDENTIFYING INJECTOR TERMINALS
Injector No. (1) Terminal No. Wire Color 1 12 Yellow 2 11 Black/Red 3 25 Black/White 4 24 Black (1) Terminals are located in ECM E5 connector. - Disconnect injector of misfiring cylinder. Using ohmmeter, measure resistance between injector terminals. If resistance is 13.4-14.2 ohms at 68°F (20°C), check for open or short circuit in wiring harness between ECM and injector. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair wiring as necessary. If resistance is not 13.4-14.2 ohms, replace injector.
- Check fuel pressure. See BASIC TESTING article. Repair fuel pressure as necessary. If fuel pressure is okay, check fuel injector performance. See SYSTEM/COMPONENT TESTS - 1.6L article. Replace fuel injectors as necessary.
- If all injectors are okay, check EGR system. See SYSTEM/COMPONENT TESTS - 1.6L article. Repair EGR system as necessary. If EGR system is okay, check MAP sensor and ECT sensor. See SYSTEM/COMPONENT TESTS - 1.6L article. Replace as necessary. If both components are okay, also check engine compression, valve clearance and valve timing. See BASIC TESTING article.