Chart A-3, Engine Cranks But Won't Run (Impulse Turbo): Notes
NOTE:
Test numbers refer to test numbers on diagnostic chart.
- When ignition is turned on, the CHECK ENGINE light should come ON. This test proves battery voltage and ignition voltage are being supplied to ECM. If no ALDL data (trouble codes) are displayed on Scan tester, this may be due to ECM problem. See appropriate chart in TESTS W/CODES article in the ENGINE PERFORMANCE Section to diagnose CHECK ENGINE light. If TPS voltage is more than 2.5 volts, engine may be in "clear flood" mode, which causes starting problems. Engine will not start without ignition reference signals. Scan tester should indicate engine speed (RPM) during cranking.
- If engine speed was indicated during cranking, ignition module is receiving a crank signal. No spark in this test indicates ignition module is not triggering coil or there is a secondary ignition problem.
- Test light should flash, indicating ECM is controlling injectors. Test light brightness is not important.
- This test determines if ignition module is not generating reference signal, or if wiring or ECM is at fault. By touching and removing test light to battery voltage on Yellow/Red wire, ignition reference signal should be generated. If engine speed is indicated, ECM and wiring are okay.
- This checks for ignition voltage at injector harness connector. Disconnect injector harness connector before probing terminal "B". Reconnect connector after test.
- Checks for open in Blue/White wire or Blue/Yellow wire from connector to ECM. Ensure injector harness is connected.
- Disconnect ECM C-D connector and check injector jumper circuits with a DVOM.