GM Service Manual Online
For 1990-2009 cars only

Object Number: 215001  Size: SF
Engine Controls Components
CKP and CMP Sensors, KS and Tachometer
Handling ESD Sensitive Parts Notice

Circuit Description

The Crankshaft Position Sensor (CKP) is mounted in front of the engine block under the timming chain cover. The CKP sensor works in conjunction with a 24X reluctor wheel mounted on the front of the crankshaft. The CKP sensor has a B+ power supply, a ground, and a signal circuit.

As the crankshaft rotates, the reluctor wheel teeth interrupt a magnetic field produced by a magnet within the sensor. The sensor's internal circuitry detects this and produces a signal which the PCM reads. The PCM uses this signal to accurately measure crankshaft velocity which is a variable used for spark and fueling.

The PCM also monitors the CKP sensor signal circuit for malfunctions. When the PCM detects a CKP sensor that is out of normal operating range, the PCM will set this DTC .

Conditions for Running the DTC

    • Engine Speed is between 500 and 4000 RPM.
    • Ignition Voltage is between 5.0 and 17.0 volts.

Conditions for Setting the DTC

The PCM determines that the CKP sensor signal is out of range for less than 1 second.

Action Taken When the DTC Sets

    •  The PCM will illuminate the malfunction indicator lamp (MIL) on the second consecutive drive trip that the diagnostic runs and fails.
    •  The PCM will record operating conditions at the time the diagnostic fails. The first time the diagnostic fails, this information will be stored in Failure Records. If the diagnostic reports a failure on the second consecutive drive trip, the operating conditions at the time of failure will be written to Freeze Frame and the Failure record will be updated.

Conditions for Clearing the MIL/DTC

    • The PCM will turn the MIL OFF after 3 consecutive drive trips that the diagnostic runs and does not fail.
    • A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles (coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant temperature exceeds 70°C (160°F) during the same ignition cycle.
    • Use the scan tool Clear Information function.
    • Disconnect the PCM battery feed for 30 seconds.

Diagnostic Aids

Important: Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing/replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion into the PCM.

The following problems may cause this DTC to set:

    • Poor connections/terminal tension at the sensor.
    • Crankshaft reluctor wheel damage or improper installation.
    • The sensor coming in contact with the reluctor wheel.
    • The engine running out of fuel.
    • If the crankshaft rotates backwards, this DTC will set. This condition is only with vehicles equipped with a manual transmission. This condition can occur when a vehicle is on an incline and the clutch is released and an engine stall occurs.

Using Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data can aid in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also aid determining how many ignition cycles the diagnostic reported a pass and/or a fail. Operate the vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature etc.) that you observed. This will isolate when the DTC failed. For an intermittent condition, refer to Symptoms

Excess crankshaft end play will cause 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

An improperly installed crankshaft could cause excess crankshaft end play. Refer to Engine Mechanical for excess crankshaft end play diagnosis.

For an intermittent, refer to Symptoms .

Test Description

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

  1. This step verifies that the malfunction is present.

  2. This step checks for EMI (Electro Magnetic Interference) on the CKP sensor circuits.

  3. Vertical lines across the face of the sensor could indicate foreign material passing between the CKP sensor and the reluctor wheel. Non vertical lines across the face of the sensor may indicate a crack in the CKP sensor. Either of these conditions causes this DTC to set.

  4. Damage to the reluctor wheel would affect the CKP sensor output. Inspect the reluctor wheel, by rotating the crankshaft while viewing the reluctor wheel through the CKP sensor hole. If you cannot determine if the reluctor wheel is damaged, the timming cover may have to be removed. Refer to Engine Front Cover Removal in Engine Mechanical.

Step

Action

Value(s)

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

Important: If DTC P0335 is also set, diagnose DTC P0335 before proceeding with this DTC.

  1. Install a scan tool.
  2. Idle the engine for 2 minutes.

Does the scan tool indicate that DTC P0336 failed this ignition?

--

Go to Step 3

Go to Diagnostic Aids

3

  1. Visually/Physically inspect all circuits going to the Crankshaft Position sensor for the following:
  2. • Routed to close to secondary ignition wires or components
    • Routed to close to after-market add on electrical equipment
    • Routed to close to solenoids, relays and motors
  3. If you find incorrect routing, correct the harness routing.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 4

4

  1. Check the terminal contact at the CKP sensor.
  2. Repair/replace the terminal if you find a problem. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 5

5

  1. Check the terminal contact at the PCM for the CKP sensor circuits.
  2. Repair/replace the terminal if you find a problem. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 6

6

  1. Remove the CKP sensor. Refer to Crankshaft Position Sensor Replacement and Crankshaft Position Sensor Reluctor Ring Replacement .
  2. Inspect the CKP sensor for signs of damage.

Did you find and correct the condition?

--

Go to Engine Front Cover Removal in Engine Mechanical

Go to Step 7

7

Inspect the CKP reluctor wheel for damage.

Did you find and correct the condition?

--

Go to Engine Front Cover Removal in Engine Mechanical

Go to Step 8

8

Replace the CKP sensor. Refer to Crankshaft Position Sensor Replacement and Crankshaft Position Sensor Reluctor Ring Replacement .

Is the action complete?

--

Go to Step 9

--

9

  1. Select the Diagnostic Trouble Code (DTC) option and the Clear DTC option using the scan tool.
  2. Idle the engine at the normal operating temperature.
  3. Select the Diagnostic Trouble Code (DTC) option and the Specific DTC option, then enter the DTC number using the scan tool.
  4. Operate vehicle within the Conditions for Running this DTC as specified in the supporting text, if applicable.

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

--

Go to Step 10

Go to Step 2

10

Select the Capture Info option and the Review Info option using the scan tool.

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

--

Go to the applicable DTC table

System OK