Engine Speed Sensors
- Remove Gray (engine RPM) and Black (ignition timing reference) connectors from bracket near ignition coil. For each connector, check continuity between terminals No. 1 and No. 2. See Fig 2 . Ohmmeter reading should be 1000 ohms.
- If reading is not 1000 ohms, replace sensor(s). If reading is 1000 ohms, check continuity between terminals No. 1 and No. 3, and terminals No. 2 and No. 3 of each connector. If ohmmeter indicates infinity, go to next step. If ohmmeter does not indicate infinity, replace sensor(s).
- Unplug connector from ECU. Check wiring, on harness side of connectors, between each sensor and ECU. See ENGINE SPEED SENSOR CIRCUITS table. See Figure and Figure . Ensure resistance of each wire between ECU and sensor connectors is zero ohm.
- 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 ECU.
ENGINE SPEED SENSOR CIRCUITS
| Sensor Harness Connector Pin | ECU Harness Connector Terminal | |
|---|---|---|
| Gray (Engine RPM) | ||
| 1 | 29 | |
| 2 | 11 | |
| 3 | 28 | |
| Black (Ignition Timing Reference) | ||
| 1 | 13 | |
| 2 | 12 | |
| 3 | 28 | |
NOTE:
Terminal identifications for Hall Effect sending unit are located on connector.