DTC 3-1-4

3-1-4 CAMSHAFT POSITION SENSOR SIGNAL

Preconditions for DTC
^ If the ECM does not receive any signal from the Camshaft Position (CMP) sensor for 2.4 engine revolutions, DTC 3-i-4 is set at the next attempt to start the engine.

Substitute value
^ At the next start attempt, the fuel injection and ignition sequences will be absent.

Fault sources
^ Signal lead short circuited to ground or voltage.
^ Break in signal, voltage or ground lead.
^ Contact resistance in connectors.
^ Defective Camshaft Position (CMP) sensor.

Fault symptoms
^ Engine does not start.

TESTING PROCEDURE





Other DTCs
^ Read off the other DTCs.

If DTC 1-2-3, 4-1-1 and possibly 4-1-3 are stored:
- Check the Throttle Position (TP) Sensor's, Engine Coolant Temperature (ECT) Sensor's, Camshaft Position (CMP) Sensor's and EGR Temperature Sensor's joint connection A18 on the ECM for signs of contact resistance and oxidation.
If none of the above DTCs are stored:
- Check Status message.





Status Message
^ Check current status message.

If Status message is: Permanent fault:
- Proceed to: PERMANENT FAULT section below.
If Status message is: Intermittent fault:
- Proceed to: INTERMITTENT FAULT section below.

PERMANENT FAULT





Check the Ground Lead
^ Switch Ignition OFF.
^ Wait for about 150 seconds.
^ Disconnect the CMP sensor.
^ Connect an ohmmeter between CMP sensor connector 1 (to ECM) and ground.

The ohmmeter should show approx. 0 ohms.

If reading is OK:
- Check the voltage lead.
If reading is incorrect:
- Check ECM connector.





Check of ECM Connector
^ Switch Ignition OFF.
^ CMP sensor disconnected.
^ Rectify the ECM's connector with regard to contact resistance and oxidation.
^ ECM connected.





^ Connect an ohmmeter between CMP sensor connector 1 (to ECM) and ground.

The ohmmeter should show approx. 0 ohms.

If reading is OK:
- The source of the DTC is poor contact in the ECM's connector.
If reading is incorrect:
- Check the lead between CMP sensor connector 1 and ECM A18 for signs of a break.





Check of Voltage Lead
^ Switch Ignition ON.
^ CMP sensor disconnected.
^ Connect a voltmeter between CMP sensor's connector 3 (to ECM) and ground.

The voltmeter should show battery voltage.

If reading is OK:
- Check of signal lead.
If reading is incorrect:
- Check of ECM's connector.





Check of ECM's Connector
^ Switch Ignition OFF.
^ CMP sensor disconnected.
^ Rectify the ECM's connector with regard to contact resistance and oxidation.
^ ECM connected.
^ Switch Ignition ON.





^ Connect a voltmeter between CMP sensor's connector 3 (to ECM) and ground.

The voltmeter should show battery voltage.

If reading is OK:
- The source of the DTC is poor contact in the ECM's connector.
If reading is incorrect:
- Check the lead between the CMP sensor's connector 3 and ECM A36 for signs of a break.





Check of Signal Lead
^ Switch Ignition ON.
^ CMP disconnected.
^ Connect a voltmeter between the CMP sensor's connector 2 (to ECM) and ground.

The voltmeter should show approx. 5 Volts.

If reading is OK:
- Check the CMP sensor.
If the voltmeter shows more than approx. 5 Volts:
- Check the lead between the CMP sensor's connector 2 and ECM A21 for signs of short circuiting to voltage supply.
- After rectification: Check the CMP sensor signal.
If the voltmeter shows less than approx. 5 Volts:
- Check the signal lead's resistance to ground.





Check the signal lead's resistance to ground
^ Switch Ignition OFF.
^ Wait for about 150 seconds.
^ CMP sensor disconnected.
^ Connect an ohmmeter between the CMP sensor's connector 2 (to ECM) and ground.

If the ohmmeter shows infinite resistance:
- Check the ECM's connector.
If the ohmmeter shows approx. 0 ohms:
- Check the lead between the CMP sensor's connector 2 and ECM A21 for signs of short circuiting to ground.





Check of ECM Connector
^ Switch Ignition OFF.
^ CMP sensor disconnected.
^ Rectify the ECM's connector with regard to contact resistance and oxidation.
^ ECM connected.





^ Connect an ohmmeter between CMP sensor connector 2 (to ECM) and ground.

The ohmmeter should show 0.5 - 3.0K ohms.

If reading is OK:
- The source of the DTC is poor contact in the ECM's connector.
If reading is incorrect:
- Check the lead between CMP sensor connector 2 and ECM A21 for signs of a break.





Check of the CMP Sensor
^ Connect the CMP Sensor.
^ Try STARTING the engine.

If the engine starts:
- The source of the DTC is poor contact in the CMP sensor's connector and/or ECM's connector. Rectify the connectors with regard to contact resistance and oxidation.
If the engine does not start:
- Test with new CMP sensor.





Check of the CMP Sensor Signal
^ The CMP sensor may break as a sequential fault resulting from short circuiting of the signal lead to voltage.
^ Check the CMP sensor as follows:
^ Connect the CMP sensor.
^ Try to START the engine.

If the engine starts:
- CMP sensor is OK.
If the engine does not start:
- Test with new CMP sensor.

INTERMITTENT FAULT

Check of the Leads and Connectors
^ Check the CMP sensor's and the ECM's connectors for signs of loose connection, contact resistance and oxidation.
^ Check the lead between CMP sensor connector 1 and ECM A18 for signs of an intermittent break.
^ Check the lead between CMP sensor's connector 2 and ECM A21 for signs of an intermittent break, intermittent short circuiting to voltage supply.
^ Check the lead between CMP sensor connector 3 and ECM A36 for signs of an intermittent break.