P0340-CAMSHAFT POSITION SENSOR CIRCUIT

For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The Camshaft Position (CMP) Sensor is a hall effect type sensor. The sensor produces a 5 Volt digital signal (square wave). The PCM provides a 5 Volt supply, 5 Volt sensor signal and ground to the CMP Sensor. The sensor is positioned near the front of the Valve Cover over the exhaust camshaft. As the camshaft rotates, the teeth on the eccentric pass closely to the CMP sensor triggering the hall-effect switch causing the digital switching of the sensor signal from high (5 Volts) to low (0 Volts).

When Monitored:
With the engine speed above 50 RPM.
Set Condition:
The Powertrain Control Module (PCM) does not receive a signal from the Camshaft Position Sensor when the Crankshaft Position Sensor indicates engine RPM.

Possible Causes
(K844) CMP 5-VOLT SUPPLY CIRCUIT OPEN/HIGH RESISTANCE
(K844) CMP 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
(K944) CMP SENSOR GROUND CIRCUIT OPEN/HIGH RESISTANCE
(K44) CAMSHAFT POSITION SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE
(K44) CMP SENSOR SIGNAL CIRCUIT OPEN/HIGH RESISTANCE
(K44) CMP SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
(K844) CMP 5-VOLT SUPPLY CIRCUIT SHORTED TO THE (K944) CMP SENSOR GROUND CIRCUIT
(K44) CMP SENSOR SIGNAL CIRCUIT SHORTED TO THE (K944) CMP SENSOR GROUND CIRCUIT
CAMSHAFT POSITION SENSOR
POWERTRAIN CONTROL MODULE (PCM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

1. VERIFY ACTIVE DTC

NOTE: The Timing Belt/Chain must be correctly installed and operational before diagnosis can be made. Refer to the Service Information to ensure the timing belt is properly installed.

NOTE: If the PCM detects and stores a DTC, the PCM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the scan tool at the same time the DTC is displayed. Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC.

1.	Turn the ignition on.

2.	With the scan tool, erase the PCM DTCs.

3.	Attempt to start the engine cranking the engine for at least 7 seconds.

4.	With the scan tool, read the PCM DTCs.

NOTE: If any Sensor Reference o DTCs are present, perform the applicable diagnostic procedure before continuing with this test.

Does the scan tool display this DTC?

Yes

Go To 3

Go To 2

2. TEST DRIVE

1.	Turn the ignition on.

2.	With the scan tool, erase the PCM DTCs.

3.	Test drive the vehicle.

4.	With the scan tool, read the PCM DTCs.

Does the scan tool display this DTC?

Yes

Go To 3

Perform the INTERMITTENT DTC diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

3. CHECK THE (K44) CAMSHAFT POSITION SENSOR SIGNAL CIRCUIT

1.	Turn the ignition off.

2.	Disconnect the Camshaft Position Sensor harness connector.

3.	Turn the ignition on.

4.	Measure the voltage of the (K44) CMP Sensor Signal circuit at the CMP Sensor harness connector.

Select the appropriate voltage reading.

Voltage is above 5.2 Volts

Go To 4

Voltage is between 4.8 and 5.2 Volts

Go To 5

Voltage is below 4.8 Volts

Go To 11

4. CHECK THE (K44) CAMSHAFT POSITION SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE

1.	Turn the ignition off.

2.	Disconnect the PCM harness connectors.

3.	Remove the ASD Relay.

4.	Connect a jumper wire between cavity 30 and cavity 87 of the ASD Relay connector.

5.	Turn the ignition on.

6.	Measure the voltage of the (K44) CMP Position Sensor Signal circuit at the CMP Sensor harness connector.

Is the voltage below 1.0 Volt?

Yes

Replace and program the Powertrain Control Module in accordance with the service information.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

Repair the (K44) Camshaft Position Sensor Signal circuit for a short to voltage.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

5. CHECK THE (K844) CAMSHAFT POSITION SENSOR 5-VOLT SUPPLY CIRCUIT

1.	Measure the voltage of the (K844) CMP Sensor 5-Volt Supply circuit at the CMP Sensor harness connector.

Select the appropriate voltage reading.

Voltage is above 5.2 Volts

Repair the (K844) CMP 5-Volt Supply circuit for a short to voltage.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

Voltage is between 4.8 and 5.2 Volts

Go To 6

Voltage is below 4.8 Volts

Go To 8

6. CHECK THE (K944) CAMSHAFT POSITION SENSOR GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE

1.	Turn the ignition off.

2.	Disconnect the PCM C1 harness connector.

3.	Measure the resistance of the (K944) CMP Sensor Ground circuit between the CMP Sensor harness connector and the PCM C1 harness connector.

Is the resistance below 5.0 Ohms?

Yes

Go To 7

Repair the (K944) CMP Sensor Ground circuit for an open or high resistance.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

7. DAMAGED CAMSHAFT POSITION SENSOR OR CAMSHAFT

1.	Turn the ignition off.

2.	Remove the CMP Sensor.

3.	Inspect the CMP Sensor for conditions such as loose mounting screws, damage, or cracks.

4.	Inspect the Camshaft Tone Wheel for conditions such as damage, debris or cracked teeth.

Is there any evidence of these conditions?

Yes

Replace the damaged Camshaft Position Sensor or Camshaft Tone Wheel in accordance with the service information.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

Replace and program the Powertrain Control Module in accordance with the service information.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

8. CHECK THE (K844) CAMSHAFT POSITION SENSOR 5-VOLT SUPPLY CIRCUIT FOR AN OPEN/HIGH RESISTANCE

1.	Turn the ignition off.

2.	Disconnect the PCM C1 harness connector.

3.	Measure the resistance of the (K844) CMP 5-Volt Supply circuit between the PCM C1 harness connector and the CMP Sensor harness connector.

Is the resistance below 5.0 Ohms?

Yes

Go To 9

Repair the (K844) CMP 5-Volt Supply circuit for an open or high resistance.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

9. CHECK THE (K844) CAMSHAFT POSITION SENSOR 5-VOLT SUPPLY CIRCUIT FOR A SHORT TO GROUND

1.	Measure the resistance between ground and the (K844) CMP Sensor 5-Volt Supply circuit at the CMP Sensor harness connector.

Is the resistance above 10k Ohms?

Yes

Go To 10

Repair the (K844) CMP Sensor 5-Volt Supply circuit for a short to ground.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

10. CHECK FOR THE (K844) CAMSHAFT POSITION SENSOR 5-VOLT SUPPLY CIRCUIT SHORTED TO THE (K944) CMP SENSOR GROUND CIRCUIT

1.	Measure the resistance between the (K844) CMP Sensor 5-Volt Supply circuit and the (K944) CMP Sensor Ground circuit at the CMP Sensor harness connector.

Is the resistance above 10k Ohms?

Yes

Replace and program the Powertrain Control Module in accordance with the service information.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

Repair the (K844) CMP Sensor 5-Volt Supply circuit for a short to the (K944) CMP Sensor Ground circuit.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

11. CHECK THE (K44) CAMSHAFT POSITION SENSOR SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE

1.	Turn the ignition off.

2.	Disconnect the PCM harness connectors.

3.	Measure the resistance of the (K44) CMP Sensor Signal circuit between the PCM C1 harness connector and the CMP Sensor harness connector.

Is the resistance below 5.0 Ohms?

Yes

Go To 12

Repair the (K44) CMP Sensor Signal circuit for an open or high resistance.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

12. CHECK THE (K44) CAMSHAFT POSITION SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND

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

Is the resistance above 10k Ohms?

Yes

Go To 13

Repair the (K44) CMP Sensor Signal circuit for a short to ground.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

13. CHECK FOR THE (K44) CAMSHAFT POSITION SENSOR SIGNAL CIRCUIT SHORTED TO THE (K944) CAMSHAFT POSITION SENSOR GROUND CIRCUIT

1.	Measure the resistance between the (K44) CMP Sensor Signal circuit and the (K944) CMP Sensor Ground circuit at the CMP Sensor harness connector.

Is the resistance above 10k Ohms?

Yes

Replace and program the Powertrain Control Module in accordance with the service information.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

Repair the (K44) CMP Sensor Signal circuit for a short to the (K944) CMP Sensor Ground circuit.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

P0340-CAMSHAFT POSITION SENSOR CIRCUIT

P0340-CAMSHAFT POSITION SENSOR CIRCUIT

Theory of Operation

Possible Causes