For 1990-2009 cars

### Circuit Description

The ECM performs internal tests on the microprocessor and some specific data coming into the processor.

### Conditions for Running the DTC

The engine speed must be more than 1,120 RPM.

### Conditions for Setting the DTC

The ECM determines that an internal data test did not pass.

### Action Taken When the DTC Sets

The ECM illuminates the malfunction indicator lamp (MIL) and records the operating conditions in the Freeze Frame on the first drive trip that the diagnostic runs and fails.

### Conditions for Clearing the MIL/DTC

• | The ECM turns OFF the MIL after 3 consecutive drive trips that the diagnostic runs and passes.

• | A History DTC clears after forty consecutive warm-up cycles in which no failures are reported by this or any other emission related diagnostic.

• | The scan tool clears the MIL/DTC.

### Test Description

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

1. Diagnose any other stored DTCs prior to diagnosing the P0606. DTCs for the throttle position sensor and other sensors may cause the ECM to set a P0606.

#### DTC P0606 ECM Internal Performance

Step | Action | Values | 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 | With a scan tool, observe the DTC information. Are any other DTCs set? | -- | Go to the applicable DTC table | Go to Step 3
3 | Important:

• | Perform the Idle Learn Procedure when replacing the ECM or throttle body.

• | This vehicle is equipped with a theft deterrent system that interfaces with the ECM. Program the new ECM with the frequency code of the theft deterrent module that is currently on the vehicle.

Replace the ECM. Refer to Engine Control Module Replacement/Programming .

Is the action complete?

--

Go to Step 4

--

4 |

1. Using the scan tool, clear the DTCs.
2. Start the engine.
3. Allow the engine to idle until the engine reaches the normal operating temperature.
4. Select DTC and the Specific DTC function.
5. Enter the DTC number that was set.
6. Operate the vehicle within the Conditions for Running this DTC, until the scan tool indicates that the diagnostic Ran.

Does the scan tool indicate that the diagnostic Passed?

--

Go to Step 5

Go to Step 2

5 | Does the scan tool display any additional undiagnosed DTCs? | -- | Go to the applicable DTC table | System OK