GM Service Manual Online
For 1990-2009 cars only

Description

This diagnostic applies to internal microprocessor integrity conditions within the engine control module (ECM). This diagnostic also addresses if the ECM is not programmed.

Test Description

The number below refers to the step number on the diagnostic table.

  1. A DTC P0602 indicates the ECM is not programmed.

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check-Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

Is DTC P0602 set?

Go to Step 3

Go to Step 5

3

Program the ECM. Refer to ECM Programming .

Does DTC P0602 reset?

Go to Step 4

Go to Step 6

4

  1. Ensure that all tool connections are secure.
  2. Ensure the programming equipment is operating correctly.
  3. Ensure the correct software/calibration package is used.
  4. Attempt to program the ECM. Refer to ECM Programming.

Does DTC P0602 reset?

Go to Step 5

Go to Step 6

5

Replace the ECM. Refer to Engine Control Module Replacement .

Did you complete the replacement?

Go to Step 6

--

6

  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.

Did the DTC fail this ignition?

Go to Step 2

Go to Step 7

7

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

Go to Diagnostic Trouble Code (DTC) List

System OK