P0340-CAMSHAFT POSITION SENSOR CIRCUIT





For a complete wiring diagram Refer to Section 8W.



Possible Causes
(F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO BATTERY VOLTAGE
(F856) 5-VOLT SUPPLY CIRCUIT OPEN
(F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
(K44) CMP SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE
(K44) CMP SIGNAL CIRCUIT OPEN
(K44) CMP SIGNAL CIRCUIT SHORTED GROUND
(K44) CMP SIGNAL CIRCUIT SHORTED TO THE (F856) 5-VOLT SUPPLY CIRCUIT
(K900) SENSOR GROUND CIRCUIT OPEN
CAMSHAFT POSITION SENSOR
CRANKSHAFT POSITION SENSOR
PCM

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).



Diagnostic Test

1. ACTIVE DTC

Crank the engine.
Ignition on, engine not running.
With a scan tool, select View DTCs.

Is the DTC Active at this time?

Yes


No

2. (F856) 5-VOLT SUPPLY CIRCUIT



Turn the ignition off.
Disconnect the CMP Sensor harness connector.
Ignition on, engine not running.
Measure the voltage on the (F856) 5-volt Supply circuit in the CMP Sensor harness connector.

Is the voltage between 4.5 and 5.2 volts?

Yes


No

3. (K44) CMP SIGNAL CIRCUIT



Measure the voltage on the (K44) CMP Signal circuit in the CMP Sensor harness connector.

Is the voltage between 4.5 and 5.0 volts?

Yes


No

4. (K900) SENSOR GROUND CIRCUIT OPEN



Turn the ignition off.
Disconnect the C2 PCM harness connector.

CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.


Measure the resistance of the (K900) Sensor ground circuit from the CMP Sensor harness connector to the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms?

Yes


No

5. (K44) CMP SIGNAL CIRCUIT SHORTED TO THE (F856) 5-VOLT SUPPLY CIRCUIT



Measure the resistance between the (K44) CMP Signal circuit and the (F856) 5-volt Supply circuit in the CMP Sensor harness connector.

Is the resistance below 5.0 ohms?

Yes


No

6. CAMSHAFT POSITION SENSOR

NOTE: Inspect the Camshaft sprocket for damage per the Service Information. If a problem is found repair as necessary.



If there are no possible causes remaining, view repair.

Repair

7. (K44) CMP SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE



Turn the ignition off.
Disconnect the C2 PCM harness connector.
Ignition on, engine not running.
Measure the voltage on the (K44) CMP Signal circuit in the CMP Sensor harness connector.

Is the voltage above 0 volts?

Yes


No

8. (K44) CMP SIGNAL CIRCUIT OPEN



Turn the ignition off.

CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.


Measure the resistance of the (K44) CMP Signal circuit from the CMP Sensor harness connector to the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms?

Yes


No

9. (K44) CMP SIGNAL CIRCUIT SHORTED TO GROUND



Measure the resistance between ground and the (K44) CMP Signal circuit in the CMP Sensor harness connector.

Is the resistance below 100 ohms?

Yes


No

10. (F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO BATTERY VOLTAGE



Turn the ignition off.
Disconnect the C1 PCM harness connector.
Ignition on, engine not running.
Measure the voltage on the (F856) 5-volt Supply circuit in the CMP Sensor harness connector.

Is the voltage above 0 volts?

Yes


No

11. (F856) 5-VOLT SUPPLY CIRCUIT OPEN



Turn the ignition off.

CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.


Measure the resistance of the (F856) 5-volt Supply circuit between the CMP Sensor harness connector to the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms?

Yes


No

12. (F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND



Measure the resistance between ground and the (F856) 5-volt Supply circuit in the CMP Sensor harness connector.

Is the resistance below 100 ohms?

Yes


No

13. PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.


Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

Were there any problems found?

Yes


No

14. ERRATIC CMP SIGNAL

With a lab scope probe and the Miller special tool #6801, back probe the (K44) CMP Signal circuit in the CMP harness connector.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.


Ignition on, engine not running.
Wiggle the related wire harness and lightly tap the Camshaft Position Sensor.
Observe the lab scope screen.
Allow the engine to idle.
Observe the lab scope screen.

Did the CMP Sensor generate any erratic pulses?

Yes


No

15. ERRATIC CKP SIGNAL

Turn the ignition off.
With a lab scope probe and the Miller special tool #6801, backprobe the (K24) CKP Signal circuit in the CKP harness connector.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.


Ignition on, engine not running.
Wiggle the related wire harness and lightly tap on the Crankshaft Position Sensor.
Observe the lab scope screen.
Allow the engine to idle.
Observe the lab scope screen.

Did the CKP Sensor generate any erratic pulses?

Yes


No