GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The powertrain control module (PCM) uses the crankshaft position (CKP) sensor to detect crankshaft speed and position. The CKP sensor connects to the PCM through the following circuits:

    • The 12-volt reference circuit
    • The low reference circuit
    • The CKP sensor 1 signal circuit

If the PCM detects no signal from the CKP sensor for more than 3 seconds, DTC P0335 sets.

Conditions for Running the DTC

    • DTCs P0101, P0102, P0103, P0341 are not set.
    • The camshaft position (CMP) sensor is incrementing.
    • The mass air flow (MAF) is more than 3 g/s while the engine is cranking.
    • The MAF is more than 5 g/s while the engine is running.

Conditions for Setting the DTC

The PCM detects 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.

Step

Action

Values

Yes

No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module 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

Attempt to start the engine.

Does the engine start and run?

--

Go to Step 3

Go to Step 4

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

Important: An internally shorted camshaft position (CMP) sensor can cause DTC P0335 to set. Test this circuit for a short to ground before proceeding with this diagnostic table. Refer to Diagnostic Trouble Code (DTC) List .

  1. Disconnect the crankshaft position (CKP) sensor harness connector.
  2. Turn ON the ignition, with the engine OFF.
  3. Measure the voltage from the CKP sensor 12-volt reference circuit and a good ground with the DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

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 with the DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Does the DMM display the specified value?

B+

Go to Step 6

Go to Step 8

6

  1. Turn OFF the ignition.
  2. Jumper the low reference circuit and the 12-volt reference circuit from the CKP sensor to the CKP sensor harness connector with the J 35616 Terminal Test Kit. Refer to Circuit Testing in Wiring Systems.
  3. Measure the AC duty cycle from the signal circuit of the CKP sensor to a good ground. Refer to Circuit Testing in Wiring Systems.
  4. Crank the engine.

Is the duty cycle within the specified range?

40-60%

Go to Step 9

Go to Step 10

7

Test for an open or a short to ground in the CKP sensor 12-volt reference circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 13

8

Test for an open in the CKP sensor low reference circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 13

9

  1. Test the CKP sensor signal circuit and the CKP connectors for the following conditions:
  2. • An open
    • A short to ground or low reference
    • A short to voltage or 12-volt reference
  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 13

10

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

Did you find and correct the condition?

--

Go to Step 16

Go to Step 11

11

  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
    • Crankshaft reluctor wheel damage or improper installation
    • Excessive air gap between the CKP sensor and the reluctor wheel
    • Foreign material passing between the sensor and the reluctor wheel

Did you find and correct the condition?

--

Go to Step 16

Go to Step 12

12

Visually inspect the CKP reluctor wheel for the following conditions:

    • Physical damage
    • Improper installation
    • Excessive endplay or looseness

Refer to Crankshaft Position Sensor Reluctor Ring Replacement in Engine Mechanical.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 14

13

Test for an intermittent and for a poor connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 15

14

Replace the CKP sensor. Refer to Crankshaft Position Sensor Replacement .

Did you complete the replacement?

--

Go to Step 16

--

15

Replace the PCM. Refer to Powertrain Control Module Replacement .

Did you complete the replacement?

--

Go to Step 16

--

16

  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 17

17

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