For 1990-2009 cars

### Circuit Description

The PCM used in this vehicle utilizes an Electrically Erasable Programmable Read-Only Memory (EEPROM). The EEPROM contains program information and the calibrations required for powertrain diagnostics operation.

Unlike the PROM used in past applications, the EEPROM is not replaceable. When the PCM is replaced or a calibration update is required, the PCM must be programmed using approved Techline equipment.

### Conditions for Setting the DTC

The PCM does not contain the correct program required to operate the vehicle.

### Action Taken When the DTC Sets

• | The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.

• | The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.

### Conditions for Clearing the MIL/DTC

• | The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed.

• | The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.

• | The DTC can be cleared by using the scan tool.

### Test Description

Numbers below refer to the step numbers on the Diagnostic Table.

1. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.

#### DTC P0602 - PCM Not Programmed

Step | Action | Values | 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 |

1. Program the PCM with correct software. Refer to Powertrain Control Module Replacement/Programming
2. Retest for DTC P0602.

Did DTC P0602 set?

--

Go to Step 3

System OK

3 | Important:: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is action complete? | -- | Go to Powertrain On Board Diagnostic (OBD) System Check | --