Knock Sensor (KS) System With KS Controller (C-5)

An open or short circuit on KS wire to PCM will cause a loss of 12-volt KS controller signal. This will cause PCM to fully retard ignition timing.
If scan tester is available, connect it to the DLC. Tap on engine next to knock sensor and note "knock" parameter. Knock should be indicated on scan tester.
If scan tester is not available, connect a DVOM to PCM ESC signal terminal. With engine idling, 12 volts should be present at this terminal. Using a metal object, tap on engine close to knock sensor. Voltage signal at PCM terminal should drop to zero volts, and return when knock signal ceases.
If signal does not respond as described, check knock sensor signal to KS controller. On vehicles equipped with automatic transmission, it may be necessary to place transmission in Drive for timing change to occur. Also, see KNOCK SENSOR (KS) under ENGINE SENSORS & SWITCHES .