GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1999 🢒 Catera 🢒 DTC 🢒 DTC P0602 Control Module Not Programmed

Circuit Description

This DTC indicates that the ECMs internal EEPROM has not been programmed with any vehicle software, or an error occurred during the programming.

Conditions for Running the DTC

Engine cranking

Conditions for Setting the DTC

The EEPROM has not been flashed with any vehicle software, or an error occurred during the programming.

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 three 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 diagnostic or any other emission related diagnostic.
    • The ECM battery voltage is interrupted.
    • The scan tool clears the MIL/DTC.

Test Description

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

  1. The engine may not start with this DTC set. If the fault is still present, the DTC will set during the cranking cycle.

DTC P0602 - ECM Not Programmed

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

  1. Using the scan tool, clear the DTCs.
  2. Attempt to start the engine.

Does DTC P0602 reset?

--

Go to Step 3

Go to Step 7

3
  1. Reprogram the ECM with the correct theft deterrent frequency code. Refer to EEPROM Programming .
  2. Using the scan tool, clear the DTCs.
  3. Attempt to start the engine.

Does DTC P0602 reset?

--

Go to Step 4

Go to Step 7

4
  1. Verify that the equipment being used is functioning properly and that all of the cable connections are clean and tight.
  2. Attempt to reprogram the ECM again with the correct theft deterrent frequency code.
  3. Using the scan tool, clear the DTCs.
  4. Attempt to start the engine.

Does DTC P0602 reset?

--

Go to Step 5

Go to Step 7

5

Important:: 

   • Perform the Idle Learn Procedure when replacing the ECM.
   • This vehicle is equipped with a Theft Deterrent System that interfaces with the Engine Control Module (ECM). The ECM must also be programmed 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 6

--

6
  1. Using the scan tool, clear the DTCs.
  2. Attempt to start the engine.

Does DTC P0602 reset?

--

Go to Step 2

Go to Step 7

7

Does the scan tool display any additional, undiagnosed DTCs?

--

Go to the applicable DTC table

System OK