Engine Speed Sensors
- Remove Gray (engine RPM) and Black (ignition timing reference) connectors from bracket near ignition coil. Connect ohmmeter to each sensor connector terminals No. 1 and 2. See Fig 1 . Ohmmeter reading should be 1000 ohms.
- If not, replace sensor(s). If reading is correct, check continuity between each sensor connector terminals No. 1 and 3, and 2 and 3. If ohmmeter reading is not infinity (4), replace sensor(s).
- Unplug connector from ECU. Check wiring between harness side of each sensor connector and ECU. See Figure
and Fig 1
. Ensure each wire between ECU and sensor connectors has zero ohms of resistance. See ENGINE SPEED SENSOR CIRCUITS chart.ENGINE SPEED SENSOR CIRCUITS
Sensor Terminal Connector Terminal Engine RPM (Gray) 1 29 2 11 3 28 Ignition Timing Reference (Black) 1 13 2 12 3 28 - Ensure clearance between ignition timing reference sensor and flywheel pin is .43" (1.10 mm) If engine speed sensors and wiring circuits are okay, replace control unit.