Engine Speed Sensor Signal

1-3-1 ENGINE SPEED SENSOR SIGNAL

Condition(s) for DTC
^ The DTC is recorded if the Engine Speed (RPM) Sensor does not deliver a signal during four engine revolutions, as computed by the control module with the aid of the Camshaft Position (CMP) Sensor.

Substitute value
^ None.

Fault source(s)
^ Open-circuit in signal or ground lead.
^ Signal lead short-circuited to ground or supply.
^ Contact resistance in connections.
^ Faulty RPM sensor.

Fault symptom(s)
^ Engine refuses to start but starts when signal is restored.
^ Engine stops while running.

TESTING PROCEDURE





Other DTCs
^ Read other DTCs.

If DI DTC 2-1-4 is recorded:
- Proceed to DTC 2-1-4 Engine Speed (RPM) Sensor Signal Sporadic.
If DI DTC 3-1-4 is recorded:
- Proceed to DTC 3-1-4 Camshaft position (CMP) Sensor signal.
It neither DTC is recorded:
- Check Status message.





Status message
^ Check current Status message.

If Status message is: Permanent fault, signal faulty:
- Proceed to PERMANENT FAULT, SIGNAL FAULTY Section below.
If Status message is: Intermittent fault, signal faulty:
- Proceed to INTERMITTENT FAULT, SIGNAL FAULTY Section below.

^ The fault counter indicates the number of starts during which the ICM has detected a fault free signal after the DTC has been recorded.

PERMANENT FAULT, SIGNAL FAULTY





Checking RPM sensor resistance
^ Switch OFF ignition.
^ Disconnect sensor.
^ Connect ohmmeter between sensor connector terminals 1 and 2 (on sensor side).

Instrument should indicate 200 - 400 Ohms depending on sensor temperature.

If reading is correct:
- Check ground lead.
If reading is incorrect:
- Try with new sensor.





Checking ground lead
^ Switch OFF ignition.
^ Disconnect sensor.
^ Connect ohmmeter between sensor connector terminal 1 (TCM terminal 2) and ground (ICM side).

Instrument should indicate approx. 0 Ohms.

If reading is correct:
- Check signal lead.
If reading is incorrect:
- Check lead between ICM A2 and RPM sensor connector terminal 1 (TCM terminal 2) for open-circuit.





Checking signal lead
^ Disconnect sensor.
^ Switch ON ignition.
^ Connect voltmeter between sensor connector terminals 1 and 2 (on ICM side).

Instrument should indicate 1 - 2 Volts.

If reading is correct:
- Check sensor connector.
If reading is over 5 Volts:
- Check lead between ICM A1 and sensor connector terminal 2 (TCM terminal 1) for short-circuit to supply.
If reading is approx. 0 Volts:
- Check resistance of signal lead to ground.





Checking resistance of signal lead to ground
^ Switch OFF ignition.
^ Disconnect sensor.
^ Connect ohmmeter between sensor connector terminals 1 and 2 (on ICM side).

If resistance is approx. 0 Ohms:
- Check lead between ICM A1 and sensor connector terminal 2 (TCM terminal 1) for short-circuit to ground.
If resistance is infinite (no conductivity):
- Check lead between ICM A1 and sensor connector terminal 2 (TCM terminal 1) for open-circuit.





Checking sensor connector
^ Switch OFF ignition.
^ Clean and pack sensor connector with grease to prevent contact resistance and oxidation.
^ Try to START engine.

If engine starts:
- Failure of engine to start was due to poor contact in sensor connector.
If engine does not start:
- Try with new sensor.

INTERMITTENT FAULT, FAULTY SIGNAL





Checking wiring and connections
^ Check sensor connector for loose connections, and for contact resistance and oxidation.
^ Check lead between ICM A2 and sensor connector terminal 1 (TCM terminal 2) for intermittent open-circuit.
^ Check lead between ICM A1 and sensor connector terminal 2 (TCM terminal 1) for intermittent open-circuit, intermittent short-circuit to supply and intermittent short-circuit to ground.