Tach Pulse (RPM Reference) Signal
WARNING: This page does not describe the selected car, but rather 39 other vehicles, including the 1992 Saturn SL2, 1992 Saturn SL1, 1992 Saturn SL, 1992 Saturn SC, and 1992 Pontiac Sunbird. However, it is still accessible from the selected car via links, so may be relevant.
Connect "Scan" tester to ALDL diagnostic connector. Scan low and high resolution reference pulses. Both high and low pulses should be present when engine is cranking or running. If low resolution pulse is not present, engine will not start and ECM will set Code 16 in memory. If high resolution pulse is not present, vehicle will still run; however, ECM will set Code 36 in memory. For circuit and terminal reference, see appropriate schematic in NO START - ENGINE CRANKS OK.