For 1990-2009 cars

### Circuit Description

This DTC indicates that the PCMs internal EEPROM has not been flashed with any vehicle software. If a service PCM is installed and not flashed, the engine will not run. The purpose of this DTC is to indicate that the engine cranks but will not run situation is due to an un-flashed PCM.

### Conditions for Setting the DTC

No software data is present in the PCM.

### Action Taken When the DTC Sets

• | DTC P0602 will be stored in the PCM memory when the diagnostic runs and fails.

• | The Malfunction Indicator Lamp (MIL) will not illuminate.

• | Fuel pump is disabled.

• | Injector pulsewidth is set to 0.

• | The PCM may record operating conditions at the time the diagnostic fails. This information will be stored in Failure Records.

### Conditions for Clearing the MIL/DTC

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

• | A last test failed (Current DTC) will clear when the diagnostic runs and does not fail.

• | PCM battery voltage is interrupted.

• | Using a scan tool.

### Test Description

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

1. If the flashing routine fails, verify that the equipment used is functioning properly and that all cable connections are clean and tight. Also make sure that the software you are attempting to download is correct for the PCM being flashed. If everything checks out OK, and a second attempt fails, the PCM is faulty.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to Step 2 | Go to Powertrain On Board Diagnostic (OBD) System Check
2 | Flash the PCM with the correct software. Refer to Powertrain Control Module Replacement/Programming . Does DTC P0602 reset. | -- | Go to Step 3 | Go to Step 5
3 |

1. Verify that the equipment being used is functioning properly and that all cable connections are clean and tight.
2. Attempt to flash the PCM again.

Does DTC P0602 reset.

--

Go to Step 4

Go to Step 5

4 | Replace the PCM. Is the action complete? | -- | Go to Step 5 | --
5 |

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 within the conditions for setting this DTC as specified in the supporting text, if applicable.

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

--

Go to Step 6

Go to Step 2

6 | 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