GM Service Manual Online
For 1990-2009 cars only

Object Number: 56424  Size: LF
Engine Controls Components
DIESEL PCM, CKP, FUEL TEMP, ITS
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The crankshaft position sensor is a Hall-effect type sensor that monitors crankshaft position and speed. There are four teeth 90 degrees apart on the front of the crankshaft sprocket that induce a pulse in the sensor which is transmitted to the PCM. There is a physical one to one correspondence between the pump cam and crankshaft. This is a type A DTC.

Conditions for Setting the DTC

    â€¢ 8 consecutive crank pulses missing.
    â€¢ An average of 8 consecutive crank pulses missing.

Action Taken When the DTC Sets

Backup fuel.

Conditions for Clearing the MIL/DTC

    â€¢ The PCM will turn the MIL off after three consecutive trips without a fault condition.
    â€¢ A History DTC will clear when forty consecutive warm-up cycles that the diagnostic does not fail (coolant temperature has risen 5°C (40°F) from start up coolant temperature and engine coolant temperature exceeds 71°C (160°F) that same ignition cycle.
    â€¢ Use of a Scan Tool

Diagnostic Aids

When PCM is in backup fuel, long crank times, fast idle and poor performance conditions will exist. Check for good connection at crankshaft position sensor and at PCM. Many intermittent problems are caused by poor electrical connections or wiring. When attempting to diagnose an intermittent problem, always begin by trying to reproduce the conditions under which the failure occurs. This usually involves raising the engine to a higher temperature or operating it near RPM that the problem occurs. Since heat and vibration are often the cause of intermittent, this may bring out the failure.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

  1. This step will determine if DTC P0335 is the result of a hard failure or an intermittent condition.

  2. This step checks the 5 volt reference circuit (the 5 volt reference may vary slightly).

  3. This step checks the ground circuit.

Step

Action

Value(s)

Yes

No

1

Important: Before clearing DTCs use the scan tool Capture Info to record freeze frame and failure records for reference, as data will be lost when Clear Info 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. Start and idle engine.
  2. Observe the Crank Ref. Missed display on scan tool.

Does scan tool display specified value?

8

Go to Step 4

Go to Step 3

3

DTC is intermittent. If no additional DTCs are stored, refer to the Applicable DTC Table(s) first.

Are any additional DTCs stored?

--

Go to the Applicable DTC Table

Go to Diagnostic Aids

4

  1. Ignition OFF.
  2. Disconnect the CKP sensor electrical connector.
  3. Ignition ON engine OFF.
  4. With a DVM J 39200 , measure voltage between the CKP 5 volt reference circuit and chassis ground.

Is the voltage within the specified range?

4.8-5.2V

Go to Step 5

Go to Step 7

5

Probe the sensor ground circuit with a test light connected to B+.

Is test light ON?

--

Go to Step 6

Go to Step 8

6

  1. Reconnect CKP sensor.
  2. Back probe CKP signal circuit at the PCM with a DVM J 39200 connected to ground.
  3. Crank engine.

Is the voltage greater than or equal to the specified value?

4 V

Go to Step 11

Go to Step 10

7

  1. Ignition OFF.
  2. Disconnect the PCM, and check the CKP 5 volt reference circuit for an open, short to ground, or short to the sensor ground circuit.
  3. If the CKP 5 volt reference circuit is open or shorted to ground, repair it as necessary.

Was a repair performed?

--

Go to Step 14

Go to Step 9

8

  1. Check for an open or a poor sensor ground terminal connection at the PCM.
  2. If a problem is found, repair as necessary.

Was a repair performed?

--

Go to Step 14

Go to Step 13

9

Check the CKP 5 volt reference circuit for a poor connection at the PCM and replace terminal if necessary.

Did the terminal require replacement?

--

Go to Step 14

Go to Step 13

10

  1. Ignition OFF.
  2. Disconnect the PCM, and check the CKP signal circuit for an open, short to ground, or short to the sensor ground circuit.
  3. Check the terminal connections at the CKP sensor for damage or a poor connection.
  4. If a problem is found, repair the problem as necessary.

Was a repair performed?

--

Go to Step 14

Go to Step 11

11

Check the CKP signal circuit for a poor connection at the PCM and replace terminal if necessary.

Did the terminal require replacement?

--

Go to Step 14

Go to Step 12

12

Replace the Crankshaft position sensor. Refer to Crankshaft Position Sensor Replacement . After replacing the sensor, the PCM must be programmed with a new TDC Offset. Refer to Fuel Injection Pump Top Dead Center Offset Adjustment .

Is the action complete?

--

Go to Step 14

--

13

Replace the PCM.

Important: The new PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming .

Is the action complete?

--

Go to Step 14

--

14

  1. Using the scan tool, select DTC, Clear Info.
  2. Start the engine and idle at normal operating temperature.
  3. Select DTC, Specific, then enter the DTC number which was set.
  4. Operate the vehicle until the Scan Tool indicates that the diagnostic Ran.

Does the Scan Tool indicate that this diagnostic Passed?

--

Go to Step 15

Go to Step 2

15

Using the scan tool, select Capture Info, Review Info.

Are any DTCs displayed that have not been diagnosed?

--

Go to the Applicable DTC Table

System OK