GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2001 🢒 GMC C-Series Medium Duty Truck C6/C7/C8 🢒 DTC 🢒 DTC P0335

Circuit Description

The crankshaft position (CKP) sensor signal indicates the crankshaft speed and position. The CKP sensor is connected directly to the powertrain control module (PCM), and consists of the following circuits:

    • The 12-volt reference circuit
    • The low reference circuit
    • The CKP sensor signal circuit

Conditions for Running the DTC
    • DTCs P0101, P0102, P0103, P0341, P0342, or P0343 are not set.
    • The camshaft position (CMP) sensor is transitioning.
    • The mass air flow (MAF) is more than 3 g/s in the crank mode.
    • The MAF is more than 5 g/s in the running mode.

Conditions for Setting the DTC

The PCM determines no signal from the CKP sensor for more than 3 seconds.

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
    •  The following conditions may cause this DTC to set:
       - Poor connections/terminal tension at the sensor--Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
       - Crankshaft reluctor wheel damage or improper installation
       - Excessive air gap between the CKP sensor and the reluctor wheel
       - The engine running out of fuel
       - Foreign material passing between the sensor and the reluctor wheel
    • Excess crankshaft end play causes the CKP sensor reluctor wheel to move out of alignment with the CKP sensor. This could result in any one of the following:
       - A no start
       - A start and stall
       - Erratic performance
    • For an intermittent, refer to Intermittent Conditions .

Test Description

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

  1. This step determines if the fault is present.

    2.

  2. This step simulates a CKP sensor signal to the PCM. If the PCM receives the signal, the fuel pump will operate for about two seconds.

    3.

  3. The CKP System Variation Learn Procedure must be performed anytime the relationship between the CKP sensor and the CKP reluctor wheel is changed.

  4. The CKP System Variation Learn Procedure must be performed anytime the relationship between the CKP sensor and the CKP reluctor wheel is changed.

Step

Action

Values

Yes

No

Schematic Reference: Engine Controls Schematics

1

Did you perform the Diagnostic System Check-Engine Controls?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

Does the engine start and continue to run?

--

Go to Step 3

Go to Step 4

3

  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 as the Freeze Frame/Failure Records data that you observed.

Does the DTC fail this ignition?

--

Go to Step 4

Go to Diagnostic Aids

4

Caution: Before proceeding, remove the fuses for the ignition coil and fuel injector feed circuits in order to prevent personal injury from engine rotation, sparks, and excessive engine fueling.

    Important: An internally shorted CAM sensor can cause DTC P0335 to set. Test this circuit for a short before proceeding with this diagnostic table. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

  1. Turn ON the ignition, leaving the engine OFF.
  2. Disconnect the crankshaft position (CKP) sensor harness connector. Refer to Crankshaft Position Sensor Replacement .
  3. Measure the voltage from the CKP sensor 12-volt reference circuit and a good ground using the DMM .

Does the DMM display the specified value?

B+

Go to Step 5

Go to Step 7

5

Measure the voltage between the CKP sensor 12-volt reference circuit and the CKP sensor low reference circuit using the DMM.

Does the DMM display the specified value?

B+

Go to Step 6

Go to Step 8

6

Momentarily connect the test lamp between the CKP sensor signal circuit and the CKP sensor 12-volt reference circuit.

Does the fuel pump operate when ignition voltage was applied to the CKP sensor signal circuit?

--

Go to Step 10

Go to Step 9

7
  1. Test for an open in the CKP sensor 12-volt reference circuit. Refer to Circuit Testing in Wiring Systems.
  2. If you find an open or a short to ground, repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 14

8
  1. Test for an open or a poor connection in the CKP sensor low reference circuit. Refer to Testing for Continuity or Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
  2. If you find an open or poor connection, repair the condition as necessary. Refer to Wiring Repairs or Repairing Connector Terminals in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 14

9
  1. Test the CKP sensor signal circuit for the following:
    2. • An open
    • A short to ground
    • A short to voltage
  2. Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 10

10
  1. Inspect for poor connections at the CKP sensor. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
  2. If you find a poor connection repair the condition as necessary. Refer to Repairing Connector Terminals in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 11

11

Important: The CKP System Variation Learn Procedure must be performed anytime the relationship between the CKP sensor and the CKP reluctor wheel is changed. Refer to Crankshaft Position System Variation Learn .

  1. Remove the CKP sensor. Refer to Crankshaft Position Sensor Replacement .
  2. Visually inspect the CKP sensor for the following conditions:
    3. • Physical damage
    • Loose or improper installation
    • Wiring routed too closely to secondary ignition components
  3. Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 12

12
  1. Inspect the CKP reluctor wheel for damage or looseness.
  2. If you find the CKP reluctor wheel damaged, refer to Diagnostic Aids in this DTC and Crankshaft and Bearing Installation in Engine Mechanical.
  3. Perform the CKP System Variation Learn Procedure. Refer to Crankshaft Position System Variation Learn .

Did you find and correct the condition?

--

Go to Step 16

Go to Step 13

13

  1. Replace the CKP sensor. Refer to Crankshaft Position Sensor Replacement .
  2. Perform the CKP System Variation Learn Procedure. Refer to Crankshaft Position System Variation Learn .

Did you complete the repair?

--

Go to Step 16

--

14
  1. Inspect for poor connections at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
  2. If you find a poor connection, repair the condition as necessary. Refer to Connector Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 16

Go to Step 15

15

Replace the PCM. Refer to Powertrain Control Module Replacement .

Did you complete the replacement?

--

Go to Step 16

--

16
  1. Operate the scan tool in order 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 17

Go to Step 2

17

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

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

--

Go to Diagnostic Trouble Code (DTC) List

System OK