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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2000 🢒 Seville 🢒 DTC 🢒 DTC P0340 Camshaft Position (CMP) Sensor Circuit

Object Number: 603352 Size: SF
Engine Controls Component Views
Ignition Control Module- Front Bank
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The PCM uses the camshaft position (CMP) sensor signal to determine the position of the valve train in relation to the engine cylinders. The PCM uses the CMP signal to sequence the ignition system, and the fuel injectors.

The PCM supplies power and ground to the CMP sensor. The CMP sensor returns a signal pulse in response to the reluctor track, located on the camshaft sprocket. If during operation, the PCM detects a loss of CMP sensor signal, DTC P0340 will set.

Conditions for Running the DTC

No CKP sensor DTCs set with engine running more than 400 RPM.

Conditions for Setting the DTC

The PCM detects a loss of CMP sensor signal.

Action Taken When the DTC Sets
    • The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test runs and fails.
    • The PCM stores the conditions present when the DTC set as Freeze Frame/Failure Records data.

Conditions for Clearing the MIL/DTC
    • The PCM will turn the MIL OFF after the third consecutive trip in which the diagnostic runs and passes.
    • The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
    • The DTC can be cleared by using the scan tool Clear DTC Information function.

Diagnostic Aids

If the condition is intermittent, refer to Intermittent Conditions .

Ignition system DTCs set with the ignition switch in the START position if the starter relay or the starter is inoperative. When the PCM enables starter operation, the PCM also initiates the diagnostic test routines for DTCs P0335, P0340, and P0385. If a condition exists which prevents the engine from cranking, the PCM will not receive signal input from the CKP and CMP sensors, and the DTCs will set.

If DTC P0615 is set, diagnose DTC P0615 first. If DTC P0335, P0340, and/or P0385 are set and no trouble is found, check for the following:

    • Is there a no-crank condition or an intermittent no-crank condition?
    • Was an attempt made to crank the engine with the shift lever not in P/N?

Step

Action

Values

Yes

No

1

Did you perform the Powertrain On Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

Important: If DTCs P0334, P0340, and P0385 are set, refer to DTC P0335 CKP Sensor A Circuit Performance

  1. Start the engine.
  2. Observe the CMP sensor data display on the scan tool Misfire Data List.

Does the CMP sensor data display indicate an RPM?

--

Go to Step 3

Go to Step 4

3
  1. Review and record the scan tool Fail Records Data.
  2. Operate the vehicle within the fail records conditions.
  3. With the scan tool, monitor the Specific DTC Information for DTC P0340 until the test runs.

Does the scan tool indicate that DTC P0340 failed last test?

--

Go to Step 4

Go to Diagnostic Aids

4

  1. Turn OFF the ignition.
  2. Leave the scan tool installed.
  3. Disconnect the CMP sensor harness connector.
  4. Turn ON the ignition, with the engine OFF.
  5. Connect test lamp between the CMP sensor feed and ground circuits.

Is the test lamp ON?

--

Go to Step 6

Go to Step 5

5

  1. Test for the following circuit conditions:
    2. • An open CMP sensor feed circuit
    • An open CMP sensor ground circuit
    • Poor connections at the PCM
  2. If a condition is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 11

Go to Step 10

6
  1. Turn ON the ignition, with the engine OFF.
  2. Connect test lamp to battery positive voltage.
  3. Observe the CMP sensor data display on the scan tool while repeatedly touching the test lamp to the CMP signal circuit, in the harness connector.

Does the scan tool indicate an RPM?

--

Go to Step 8

Go to Step 7

7
  1. Test the CMP sensor signal circuit for the following conditions:
    2. • An open
    • Short to voltage
    • Short to CMP sensor feed circuit
    • Short to ground
    • Short to CMP sensor ground circuit
    • Poor connections at the PCM
  2. If a condition is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 11

Go to Step 10

8

  1. Inspect for poor connections at the CMP sensor.
  2. If the condition is found, repair as necessary. Refer to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 11

Go to Step 9

9

Replace the CMP sensor. Refer to Camshaft Position Sensor Replacement .

Is the action complete?

--

Go to Step 11

--

10

Important: The replacement PCM must be programmed.

Replace the PCM. Refer to Powertrain Control Module Replacement/Programming .

Is the action complete?

--

Go to Step 11

--

11

  1. Review and record the scan tool Fail Records data.
  2. Clear the DTCs
  3. Operate the vehicle within the Conditions For Running the DTC as listed above.
  4. With the scan tool, monitor the Specific DTC Information for DTC P0340 until the test runs.

Does the scan tool indicate that DTC P0340 passed?

0V

System OK

Go to Step 2