GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1997 🢒 GMC C Pickup - 2WD 🢒 DTC 🢒 DTC P1345 Crankshaft Position (CKP)-Camshaft Position (CMP) Correlation

Object Number: 33715 Size: MF
Engine Controls Components
Engine Controls Schematics
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

Circuit Description

This DTC determines if the distributor is installed incorrectly, or if there is a mechanical malfunction in the engine. The DTC P1345 is a type A DTC.

Conditions for Setting the DTC

When the engine is running, the cam sensor reference pulse is not detected at the correct relative position to the crankshaft position sensor pulse.

Action Taken When The DTC Sets
    • The VCM turns the MIL ON when this DTC is reported and one failure has occurred.
    • The VCM records the operating conditions at the time the Diagnostic Fails. Freeze Frame and Failure Records store this information.

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

Check the following items:

    • A loose or missing distributor hold down bolt
    • A loose CMP sensor causing a variance in the sensor signal
    • Incorrectly installed distributor - 1 tooth off in either advance or retard positions
    • A loose distributor rotor on the distributor shaft
    • Excessive free play in the timing chain and gear assembly

Test Description

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

  1. This test will determine if this DTC is intermittent.

    2.

  2. When the engine speed is raised to 2000 RPM the camshaft retard offset should not vary more than 2°.

    3.

  3. If excessive pressure is used when performing this test unintentional damage to the distributor shaft could result.

    4.

  4. If the distributor is one tooth off in either the advanced or retard positions the vehicle may run but 0° camshaft retard offset will not be obtained.

    5.

  5. If 0° cannot be obtained during this procedure refer to Diagnostic Aids.

Step

Action

Value(s)

Yes

No

1

Important: Before clearing the DTCs, use the scan tool in order to record the Freeze Frame and the Failure Records for reference. This data will be lost when the Clear DTC Information function is used.

Was the Powertrain On-Board Diagnostic (OBD) System Check performed?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2
  1. Install the scan tool.
  2. Start the engine.
  3. Use the scan tool in order to monitor the engine speed.

Does the engine speed fluctuate (up to twice the desired RPM)?

--

Go to Step 3

Go to Step 4

3

Replace the Crankshaft Position Sensor. Refer to Crankshaft Position Sensor Replacement Removal Procedure.

Is the action complete?

--

Go to Step 10

--

4

Perform the Camshaft Retard Offset test procedure as follows:

  1. Install the scan tool.
  2. Start the engine.

    3. Important: The camshaft retard reading will not be accurate below 1000 RPM.

  3. Raise the engine speed to the first specified value.
  4. Monitor the camshaft retard with the scan tool.

Is the camshaft retard reading within the second specified value?

1000 RPM

0° ± 2°

Go to Step 5

Go to Step 6

5

  1. Note the camshaft retard reading from the previous step.
  2. Raise the engine speed to the first specified level.

Does the camshaft retard reading change more than the second specified value?

2000 RPM

2°

Go to Step 6

Go to Diagnostic Aids

6

With the engine at operating temperature perform the following procedure:

  1. Remove the distributor cap.
  2. Grasp the distributor rotor and gently attempt to rotate the rotor.

Does the rotor turn on the distributor shaft?

--

Go to Step 9

Go to Step 7

7

Check for proper installation of the distributor. Repair as necessary. Refer to Distributor Installation Procedure in Engine Mechanical.

Did you find a problem?

--

Go to Step 10

Go to Step 8

8

Perform the Camshaft Retard Offset adjustment procedure as follows:

  1. With the engine OFF slightly loosen the distributor hold down bolt.
  2. Start the engine and raise the engine speed to 1000 RPM.
  3. Using the scan tool monitor the camshaft retard offset.
  4. Rotate the distributor as follows:
    5. • To compensate for a negative reading rotate the distributor in the counterclockwise direction.
    • To compensate for a positive reading rotate the distributor in the clockwise direction.
  5. Repeat step 4 until 0° offset is obtained.
  6. When 0° has been obtained turn OFF the ignition and tighten the distributor hold down bolt.

Did you obtain 0° camshaft retard?

--

Go to Step 10

Go to Diagnostic Aids

9

Replace the distributor. Refer to Distributor Removal Procedure in Engine Mechanical.

Is the action complete?

--

Go to Step 10

--

10
  1. Use the scan tool in order to select the DTC and the Clear DTC Information functions.
  2. Start the Engine.
  3. Allow the engine to Idle until the normal operating temperature is reached.
  4. Select the DTC and the Specific DTC functions.
  5. Enter the DTC number which was set.
  6. Operate the vehicle within the conditions for setting this DTC as specified in the supporting text.

Does the scan tool indicate that this diagnostic ran and passed?

--

Go to Step 11

Go to Step 2

11

Use the scan tool in order to display the Capture Info and the Review Capture Info functions.

Are there any DTCs displayed that have not been diagnosed?

--

Go to The Applicable DTC Table

System OK