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For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Optra 🢒 Engine 🢒 Engine Controls - 1.8L (L79) 🢒 DTC P0342

Circuit Description

The camshaft position (CMP) sensor correlates the crankshaft to camshaft position so that the engine control module (ECM) can determine which cylinder is ready to be fueled by the injector. As the camshaft rotates, the reluctor wheel interrupts a magnetic field produced by a magnet within the sensor and sends a signal to the ECM through the signal circuit. The CMP sensor also determines which cylinder is misfiring. The circuits between the CMP sensor and the ECM consists of the following:

    • A ground circuit
    • A CMP signal circuit

If the ECM detects no pulses from the CMP sensor, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0342 Camshaft Position (CMP) Sensor Low Voltage

Conditions for Running the DTC
    • The engine is operating.
    • DTC P0342 runs continuously when the above condition is met.

Conditions for Setting the DTC

The ECM detects no CMP pulses in 32 crankshaft rotations.

Action Taken When the DTC Sets
    • The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
    • The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC
    • The control module turns OFF the malfunction indicator lamp (MIL) after 4 consecutive ignition cycles that the diagnostic runs and does not fail.
    • A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
    • Clear the MIL and the DTC with a scan tool.

Step

Action

Values

Yes

No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Controls Connector End Views

1

Did you perform the Diagnostic System Check - Engine Controls?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2
  1. Start the engine.
  2. Observe the DTC Information with a scan tool.

Did DTC P0342 fail this ignition?

--

Go to Step 4

Go to Step 3

3
  1. Observe the Freeze Frame/Failure Records for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

--

Go to Step 4

Go to Intermittent Conditions

4
  1. Turn OFF the ignition.

    2. Important: The inline fuse is located under the underhood fuse block.

  2. Inspect the inline fuse for the ignition 1 voltage circuit of the CMP sensor.

Is the fuse open?

--

Go to Step 5

Go to Step 6

5
  1. Test the ignition 1 voltage circuit of the camshaft position (CMP) sensor for a short to ground between the inline fuse and the CMP sensor.
  2. Replace the fuse, as necessary.

Did you find and correct the condition?

--

Go to Step 18

Go to Step 16

6

  1. Disconnect the CMP sensor harness connector.
  2. Turn ON the ignition, with the engine OFF.

    3. Important: Use the J 35616-200 Test Lamp Kit for this test. If the J 35616-200 is not available, use a test lamp that measures between 25-30 ohms.

  3. Probe the ignition 1 voltage circuit of the CMP sensor with a test lamp connected to a good ground.
  4. Measure the voltage from the probe of the test lamp to a good ground.

Is the voltage within 0.6 volt of the specified value?

B+

Go to Step 7

Go to Step 14

7

Connect a test lamp between the ignition 1 voltage circuit and the low reference circuit of the CMP sensor.

Does the test lamp illuminate?

--

Go to Step 8

Go to Step 15

8

Measure the voltage from the signal circuit of the CMP sensor to a good ground with a DMM.

Is the voltage within the specified range?

4.8-5.2 V

Go to Step 10

Go to Step 9

9

Test the signal circuit of the CMP sensor for the following conditions:

    • High resistance
    • An open
    • A short to ground
    • A short to voltage

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 18

Go to Step 13

10

  1. Remove the CMP sensor. Refer to Camshaft Position Sensor Replacement .
  2. Inspect the CMP sensor for the following conditions:
    3. • Physical damage
    • Loose or improper installation
    • Wiring routed too closely to the secondary ignition components
    • Excessive air gap between the CMP sensor and the reluctor wheel
    • The CMP sensor coming in contact with the reluctor wheel
    • Foreign material passing between the CMP sensor and the reluctor wheel

Did you find and correct the condition?

--

Go to Step 18

Go to Step 11

11

Important: If the reluctor wheel is damaged, replace the CMP sensor.

Inspect the CMP sensor reluctor wheel for the following conditions:

    • Physical damage
    • Improper installation
    • Excessive play or looseness

Did you find and correct the condition?

--

Go to Step 18

Go to Step 12

12

Test for an intermittent and for a poor connection at the CMP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 18

Go to Step 16

13

Test for an intermittent and for a poor connection at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 18

Go to Step 17

14

  1. Repair the ignition 1 voltage circuit of the CMP sensor for one of the following conditions:
    2. • An open
    • A short to ground
    • High resistance
  2. Replace the fuse, as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 18

--

15

Repair the low reference circuit of the CMP sensor for one of the following conditions:

    • An open
    • High resistance

Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 18

--

16
  1. Replace the CMP sensor. Refer to Camshaft Position Sensor Replacement .
  2. Replace the fuse, as necessary.

Did you complete the replacement?

--

Go to Step 18

--

17

Replace the ECM. Refer to Engine Control Module Replacement .

Did you complete the replacement?

--

Go to Step 18

--

18
  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

--

Go to Step 2

Go to Step 19

19

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List

System OK