1989 Oldsmobile Delta 88 Computers and Control Systems

1989 Oldsmobile Delta 88 V6-3800 3.8L

Computers and Control Systems: Symptom Related Diagnostic Procedures

Chart A-3 Wiring Diagram

TEST DESCRIPTION: Numbers below refer to circled numbers on the diagnostic chart.

1. This step verifies that "SERVICE ENGINE SOON" light operation, throttle position sensor, and coolant sensor signals are normal. A blinking injector test light verifies that the ECM is monitoring the fuel control signal and attempting to activate the injectors.

2. The crank sensor has been verified as functioning properly, as is evident by the blinking injector test light. A fuel pressure test at this point will separate the diagnostic path into either a fuel related fault or ignition system malfunction.

3. By testing for spark on plug leads 1, 3, and 5, each ignition coil's ability to produce at least 25,000 volts is verified. If the engine starts and runs for several seconds and dies repeatedly, consider this to be no spark on all.

4. By testing the problem coil's control circuit with a test light, a determination can be made as to the problem coil being faulty or the module's internal driver for that coil being the source of the complaint. Download File PDF

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