GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The crankshaft position (CKP) sensor contains 2 hall-effect switches in one housing. This sensor configuration produces 2 separate CKP sensor pulses. These pulses occur when 2 interrupter rings, mounted to the crankshaft balancer, the outer one containing 18 evenly spaced windows and blades, the inner one containing 3 unevenly spaced windows and blades, pass by the sensors. The 18X sensor produces 18 pulses per engine revolution. The 3X sync sensor produces 3 pulses per engine revolution, each pulse representing a pair of companion cylinders. Both sensors are connected directly to the ignition control module (ICM). The sensor wiring includes the following circuits:

    • The CKP sensor 1 signal circuit
    • The CKP sensor 2 signal circuit
    • A shared 12-volt reference circuit
    • A shared low reference circuit

The ICM uses the sensors to determine the engine position and speed. A signal converter within the ICM, using the CKP sensor 1 18X pulse, produces a digital 18X output signal to the powertrain control module (PCM) on the medium resolution engine speed signal circuit. The PCM monitors the medium resolution engine speed signal circuit for errors. If the PCM does not receive a signal from the ICM, DTC P0335 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0335 Crankshaft Position (CKP) Sensor A Circuit

Conditions for Running the DTC

    • The engine run time is more than 3 seconds.
    • This diagnostic runs continuously when the above condition is met.

Conditions for Setting the DTC

    • The PCM detects the following for every 2 engine revolutions:
       - 6 low resolution engine speed signals
       - 1 camshaft position (CMP) sensor signal
       - 0 medium resolution engine speed signals
    • The above conditions are met for more than 8 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 - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Attempt to start the engine.

Does the engine start and run?

--

Go to Step 3

Go to Step 8

3

Observe the CKP Sensor B parameter with the scan tool.

Does the CKP Sensor B parameter change with engine speed?

--

Go to Step 4

Go to Step 5

4

  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.

Does the DTC fail this ignition?

--

Go to Step 5

Go to Testing for Intermittent Conditions and Poor Connections

5

  1. Turn OFF the ignition.
  2. Disconnect the ignition control module (ICM).
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp to a good ground.
  5. Probe the medium resolution engine speed signal circuit at the ICM connector with the test lamp. Refer to Probing Electrical Connectors .

Does the test lamp illuminate?

--

Go to Step 10

Go to Step 6

6

  1. Connect the test lamp to battery voltage.
  2. Probe the medium resolution engine speed signal circuit at the ICM connector with the test lamp.

Does the test lamp illuminate?

--

Go to Step 9

Go to Step 7

7

  1. Observe the CKP Sensor B parameter with the scan tool.
  2. Probe the medium resolution engine speed signal circuit repeatedly at the ICM connector with the test lamp.

Does the CKP Sensor B change?

--

Go to Step 13

Go to Step 11

8

  1. Disconnect the crankshaft position (CKP) sensor.
  2. Turn ON the ignition, with the engine OFF.
  3. Measure the voltage from the CKP sensor 1 signal circuit to a good ground with a DMM.

Is the voltage within the specified range?

4-8 V

Go to Step 14

Go to Step 12

9

Test the medium resolution engine speed signal circuit between the ICM and the powertrain control module (PCM) for a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 20

Go to Step 19

10

Test the medium resolution engine speed signal circuit between the ICM and the PCM for a short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 20

Go to Step 19

11

Test the medium resolution engine speed signal circuit between the ICM and the PCM for an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 20

Go to Step 16

12

Test the CKP sensor 1 signal circuit for an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 20

Go to Step 15

13

Inspect for the following conditions:

    • Incorrect harness routing near secondary ignition components
    • The ignition coil arcing to the wiring harness or to the ICM
    • The ignition coils for cracks, carbon tracking, or other signs of damage--Refer to Ignition Coil Replacement .
    • Spark plug wires arcing--Refer to Spark Plug Wire Replacement .

Did you find and correct the condition?

--

Go to Step 20

Go to Step 15

14

Test for an intermittent or for poor connections at the CKP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 20

Go to Step 17

15

Test for an intermittent or for poor connections at the ICM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 20

Go to Step 18

16

Test for poor connections at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 20

Go to Step 19

17

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

Did you complete the replacement?

--

Go to Step 20

--

18

Replace the ICM. Refer to Ignition Control Module Replacement .

Did you complete the replacement?

--

Go to Step 20

--

19

Replace the PCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 20

--

20

  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 21

21

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle

System OK