DTC P0340 IC Module Cam Reference CKT No Frequency. Oldsmobile Shelby Series 1 1999

For 1990-2009 cars
Engine Controls Components
Ignition Control Module
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

### Circuit Description

The diagnostic test checks for CAM reference pulses not received when 4X reference pulses are being received. This indicates a CAM sensor circuit failure and DTC P0340 is set.

### Conditions for Running the DTC

• | DTC P0322 is not set.

• | Engine speed is 1600 RPM or less.

### Conditions for Setting the DTC

A CAM reference pulse was not received for 5.3 seconds.

### Action Taken When the DTC Sets

• | The PCM illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.

• | The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure Records.

### Conditions for Clearing the MIL/DTC

• | The PCM turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.

• | A last test failed, or current DTC, clears when the diagnostic runs and does not fail.

• | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.

• | Use a scan tool in order to clear the MIL and the DTC.

### Conditions for Clearing the MIL/DTC

• | The PCM will turn the MIL OFF after three consecutive drive trips that the diagnostic runs and does not fail.

• | A last test failed, or current DTC, will clear when the diagnostic runs and does not fail.

• | A History DTC will clear after forty consecutive warm-up cycles with no failures of any emission related diagnostic test.

• | Use a scan tool to clear DTCs.

• | Interrupting PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Clearing Diagnostic Trouble Codes in Powertrain Control Module Description .

### Test Description

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

1. Using Freeze Frame and Failure Records may assist in locating an intermittent condition. Operate the vehicle within the same conditions that you observed in the Freeze Frame and Failure Records.

2. This step tests the camshaft position (CMP) sensor and wiring. If the DMM displays a frequency, then the CMP sensor and wiring are OK.

3. This step tests the output of the ignition control module (ICM). If the DMM displays a frequency, then the ignition module is OK.

#### DTC P0340

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

1. Turn ON the ignition, with the engine OFF.
2. Review the Freeze Frame and/or Failure Records data for this DTC and observe the parameters.
3. Turn OFF the ignition for 15 seconds.
4. Attempt to start and idle the engine.
5. Monitor the CMP sensor high to low and low to high transitions with a scan tool.

Is the CMP transitioning?

--

Go to Diagnostic Aids

Go to Step 3

3

1. Turn OFF the ignition.
2. Disconnect ICM connector C3.
3. Connect the DMM between the CMP reference signal circuits, at the ICM connector C3.
4. Measure the frequency from the CMP signal circuits.
5. Monitor the DMM while cranking the engine.

Does the DMM display a frequency while cranking the engine?

--

Go to Step 4

Go to Step 7

4

1. Inspect for poor connections at the IICM for the CMP sensor signal circuits. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.
2. If you find a poor connection, repair the condition as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 11

Go to Step 5

5

1. Connect the ICM connector C3.
2. Disconnect the ICM connector C4.
3. Connect the DMM between the CMP signal terminal, at the ICM, and battery ground.
4. Measure the frequency from the ICM while cranking the engine.

Does the DMM display a frequency?

--

Go to Step 6

Go to Step 9

6

1. Disconnect the PCM connector C1.
2. Test the CMP signal circuit for the following:

• | An open circuit

• | A short to ground

• | A short to voltage

• | Poor connections

3. If you find a condition, repair as necessary. Refer to Wiring Repairs or Repairing Connector Terminals in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 11

Go to Step 10

7

1. Disconnect the CMP sensor electrical connector.
2. Test the CMP signal circuits for the following:

• | An open circuit

• | A short to ground

• | A short to voltage

• | Poor connections

3. If you find a condition, repair as necessary. Refer to Wiring Repairs or Repairing Connector Terminals in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 11

Go to Step 8

8 | Replace the CMP sensor. Refer to Camshaft Position Sensor Replacement . Is the action complete? | -- | Go to Step 11 | --
9 | Replace the ICM. Refer to Ignition Control Module Replacement . Is the action complete? | -- | Go to Step 11 | --
10 | Important: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is the action complete? | -- | Go to Step 11 | --

11

1. Select the Diagnostic Trouble Code (DTC) option and the Clear DTC option with 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 with the scan tool.
4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text, if applicable.

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

--

Go to Step 12

Go to Step 2

12 | Select the Capture Info option and the Review Info option with the scan tool. Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to the applicable DTC table | System OK