GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2002 🢒 GMC C Sierra - 2WD 🢒 DTC 🢒 DTC P1345

Circuit Description

The engine control module (ECM) monitors the crankshaft position (CKP) and the camshaft position (CMP) signals to determine if they are synchronized. If both signals are not observed by the ECM within a narrow time window, the ECM will determine that an error has occurred and DTC P1345 will set.

Conditions for Running the DTC

The engine is cranking or running.

Conditions for Setting the DTC

When the engine is cranking or running, the cam sensor pulses received by the ECM do not equal 3 or 0 per 2 crankshaft revolutions.

Action Taken When the DTC Sets
    • The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
    • The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC
    • The control module turns OFF the malfunction indicator lamp (MIL) after 3 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.

Diagnostic Aids

Inspect for the following items:

    • A loose CMP sensor causing a variance in the sensor signal
    • Excessive free play or damage of the timing gears
    • The Camshaft Reference Signal Missed parameter will only increment for an intermittent. A constant failure of the CMP sensor will not cause the parameter to increment, but will set DTC P0340.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. A condition that sets one of these DTCs may also result in a DTC P1345. Diagnose these codes before continuing with this diagnostic.

    2.

  2. A loose CMP sensor may result in a DTC P1345. Attempt to tighten the sensor to proper torque specifications. If unable to prevent CMP sensor movement, inspect the cover for damage before replacing the sensor.

    3.

  3. A cracked CMP sensor or internal breakage could result in DTC P1345. This will not be apparent unless the sensor is removed from the front engine cover.

    4.

  4. If the CMP sensor appears to be damaged by contact with the camshaft gear, you may need to remove the front engine cover and inspect for excessive camshaft end-play.

Step

Action

Yes

No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Control Module Connector End Views or 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. Observe the Freeze Frame/Failure Records data 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 as specified in the supporting text or as close to the Freeze Frame/Failure Records data that you observed.

Does the DTC fail this ignition?

Go to Step 3

Go to Intermittent Conditions

3

Do any of the following DTCs set?

    • DTC P0335
    • DTC P0336
    • DTC P0340
    • DTC P0341

If one or more of these DTCs set, go to the appropriate table and diagnose that DTC first.

Go to Diagnostic Trouble Code (DTC) List

Go to Step 4

4

Inspect for a loose CMP sensor. If the sensor cannot be tightened, the sensor must be replaced.

Does the CMP sensor move without being able to be tightened?

Go to Step 7

Go to Step 5

5

  1. Remove the CMP sensor. Refer to Camshaft Position Sensor Replacement .
  2. Inspect for a broken CMP sensor casing or a rattle inside when shaken.

Does the CMP sensor show any signs of physical damage?

Go to Step 7

Go to Step 6

6

  1. Remove the front engine cover. Refer to Engine Front Cover Replacement in Engine Mechanical - 6.6L.
  2. Check for excessive camshaft end-play. Refer to Camshaft Replacement in Engine Mechanical - 6.6L.
  3. Inspect for front engine cover damage.
  4. Inspect for timing gear misalignment or damage. Refer to Camshaft Replacement in Engine Mechanical - 6.6L.

Did you find and correct the condition?

Go to Step 8

Go to Symptoms - Engine Mechanical in Engine Mechanical - 6.6L

7

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

Did you complete the replacement?

Go to Step 8

--

8
  1. Use a scan tool to clear the DTCs.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC run and pass?

Go to Step 9

Go to Step 2

9

With a scan tool, observe the stored information, Capture Info.

Does the scan tool display any DTCs that you have not diagnosed?

Go to Diagnostic Trouble Code (DTC) List

System OK