Circuit Description
The camshaft position (CMP) sensor is a sensor designed to detect changes in a magnetic field. The control module supplies the CMP sensor with signal and ground circuits. Ignition voltage is supplied to the CMP sensor by an independent circuit. The CMP sensor produces a magnetic field whenever the ignition is ON. The CMP sensor is mounted near a reluctor wheel that is attached to the distributor shaft. When the distributor shaft rotates, or when the engine is cranking or running, the reluctor wheel changes the magnetic field. The CMP sensor converts each change in the magnetic field into a PULSE. The number of teeth on the reluctor wheel determines how many pulses the CMP sensor detects per camshaft rotation. The control module uses the CMP sensor signal in order to calculate the correct timing for sequential fuel injection.
If the VCM does not detect the CMP signal while the engine is running, this DTC will be set.
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
The camshaft position sensor reference pulse is not detected once every crankshaft revolution.
Action Taken When the DTC Sets
The VCM will turn ON the MIL after 2 consecutive driving cycles with the fault active.
Conditions for Clearing the MIL or DTC
| • | The control module turns OFF the MIL after 3 consecutive drive trips when the test has run and passed. |
| • | A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles. A warm-up cycle occurs when the coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant reaches a temperature that is more than 70°C (158°F) during the same ignition cycle. |
| • | Use a scan tool in order to clear the DTCs. |
Diagnostic Aids
A poor connection, rubbed through wire insulation, or a wire that is broken inside the insulation may cause an intermittent.
Any circuitry, that is suspected as causing the intermittent complaint, should be thoroughly checked for the following conditions:
| • | Backed out terminals |
| • | Improper mating |
| • | Broken locks |
| • | Improperly formed or damaged terminals |
| • | Poor terminal to wire connections |
| • | Physical damage to the wiring harness |
Refer to Symptoms .
Test Description
The number(s) below refer to the step number(s) in the diagnostic table.
-
This step determines if DTC P0340 is the result of a hard failure or an intermittent condition.
-
This step determines if the voltage is available to the CMP through the VCM.
-
If the feed circuit is shorted to ground, the test lamp will be ON. This step determines if the circuit is open or shorted to ground. If the circuit is OK, then the VCM connections or the VCM is faulty.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 |
Important: Before clearing the DTCs, record the Freeze Frame and the Failure Records for reference with the scan tool. This data will be lost when you use the Clear DTC Information function. Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||
Is the MIL (Malfunction Indicator Lamp) ON? | -- | |||
Is the test lamp ON? | -- | |||
Jumper the test lamp between cavities A and C of the Camshaft Position sensor connector (engine side). Is the test lamp ON? | -- | |||
5 |
Is the voltage between the specified value? | 5-7 V | ||
6 | Check the Camshaft Position sensor signal circuit for an open. Was a problem found? | -- | ||
7 | Check the Camshaft Position sensor signal circuit for a short. Was a problem found? | -- | ||
8 | The DTC is intermittent. Are there any additional DTCs stored? | -- | Go to Diagnostic Aids | |
9 | Check for an open in the Camshaft Position sensor feed circuit. Was a problem found? | -- | ||
10 | Repair the short to ground in the Camshaft Position sensor feed circuit. Refer to Wiring Repairs in Repair Instructions. Is the action complete? | -- | -- | |
11 | Repair the open in the Camshaft Position sensor Low circuit. Refer to Wiring Repairs in Repair Instructions. Is the repair complete? | -- | -- | |
12 | Check for a faulty connection at the Camshaft Position sensor. Was a problem found? | -- | ||
13 | Repair the circuit as necessary. Refer to Wiring Repairs in Repair Instructions. Is the action complete? | -- | -- | |
14 | Replace the Camshaft Position sensor. Refer to Camshaft Position Sensor Replacement in Repair Instructions. Is the action complete? | -- | -- | |
15 | Check for a faulty connection at the VCM. Was a problem found? | -- | ||
16 |
Is the action complete? | -- | -- | |
17 |
Does the scan tool indicate that this diagnostic ran and passed? | -- | ||
18 | Display the Capture Info and the Review Capture Info functions with a scan tool. Are any new DTCs displayed? | -- | Go to The Applicable DTC Table | System OK |
