For 1990-2009 cars

### Circuit Description

The circuit uses 2 different types of crankshaft position (CKP) sensors. The 7X CKP sensor is connected directly to the ignition control (IC) module, and consists of the following circuits:

• | The CKP 1 sensor signal circuit

• | The low reference circuit

The 24X CKP sensor connects directly to the powertrain control module (PCM), and consists of the following circuits:

• | The 12-volt reference circuit

• | The medium resolution engine speed signal circuit

• | The low reference circuit

### Conditions for Running the DTC

The engine is running, 3X reference pulses are being received, for a minimum of 3 seconds.

### Conditions for Setting the DTC

The ratio of 24X reference pulses to 3X reference pulses received by the PCM is incorrect.

### 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

DTC P0336 can be caused by secondary components leaking high voltage into the ignition control (IC) module. Inspect for the following conditions:

• | The incorrect harness routing near secondary ignition components

• | The ignition coil arcing to the wiring harness or to the IC module--Inspect the ignition coils for cracks, for carbon tracking, or for other signs of damage.

• | The secondary ignition wires arcing to wiring harness

• | If the DTC is intermittent, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

### Test Description

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

1. If you were sent here from DTC P0327, proceed with DTC P0336 diagnostic even if P0336 has not failed this ignition.

2. The 24X RPM on the scan tool should change each time the Medium Resolution Engine Speed Signal circuit is touched.

3. If the fuse opens in the jumper wire, there is a short to ground on the Medium Resolution Engine Speed Signal circuit.

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 |

1. Start the engine.
2. With the scan tool, observe the 24X RPM.

Does 24X RPM vary with engine speed up to approximately 1,600 RPM?

--

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.
3. Start the engine.
4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text or as close to the Freeze Frame/Failure Records data that you observed?

Does the DTC fail this ignition?

--

Go to Step 4

Go to Diagnostic Aids

4 | Important: A short to ground on the cam sensor 12-volt reference circuit can cause DTC P0336 and DTC P0327 to set. Test this circuit for a short to ground before proceeding with this diagnostic table. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

1. Turn OFF the ignition.
2. Disconnect the 24X CKP sensor connector.
3. Turn ON the ignition, with the engine OFF.
4. Connect a DMM between the 12-volt reference circuit of the 24X sensor and ground.

Does the voltage measure near the specified value?

B+

Go to Step 6

Go to Step 5

5 |

1. Turn OFF the ignition.
2. Disconnect the PCM.
3. Test the 12-volt reference circuit of the 24X CKP sensor for a short to ground or an open. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 12

6 |

1. Connect a test lamp to battery positive voltage.
2. Touch the 24X CKP sensor low reference circuit.

Does test lamp illuminate?

--

Go to Step 8

Go to Step 7

7 |

1. Turn OFF the ignition.
2. Disconnect the PCM.
3. Test the low reference circuit of the 24X CKP sensor for an open. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 12

8 |

1. Monitor 24X RPM on the scan tool.
2. Using a 5 amp fused jumper wire connected to battery positive voltage momentarily touch the Medium Resolution Engine Speed Signal circuit 5 times for a duration of 1 second each.

Does 24X RPM change EACH time the signal circuit is touched?

--

Go to Step 13

Go to Step 9

9 | Did the fuse in the jumper wire open? | -- | Go to Step 11 | Go to Step 10
10 | Test the Medium Resolution Engine Speed Signal circuit of the 24X CKP sensor for a short to voltage or an open. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 12
11 | Test the Medium Resolution Engine Speed Signal circuit of the 24X CKP sensor for a short to ground. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 12
12 | Inspect for faulty connections at the PCM. Refer to Testing for Continuity , and Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 14
13 | Inspect for faulty connections at the 24X CKP sensor. Refer to Testing for Continuity and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 15
14 | Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | -- | Go to Step 16 | --
15 | Replace 24X CKP sensor. Refer to Crankshaft Position Sensor Replacement . Did you complete the replacement? | -- | Go to Step 16 | --
16 |

1. Use the scan tool in order to clear DTCs.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Operate vehicle within 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 DTCs that you have not diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List | System OK