GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2002 🢒 GMC K Sierra - 4WD (LPG) 🢒 Engine 🢒 Engine Controls - 6.0L 🢒 DTC P0601, P0602, P0603, P0604, P0605, P0606, P0607, P1600, P1621, P1627, P1680, P1681, P1683, or P2610

Description

This diagnostic applies to internal microprocessor integrity conditions within the control module. This diagnostic also addresses if the control module is not programmed. The following DTCs are diagnosed in this DTC table:

    • DTC P0601
    • DTC P0602
    • DTC P0603
    • DTC P0605
    • DTC P0606

Test Description

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

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

DTC P0601-P0607, P1600, P1621, P1627, or P1683

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check Alternative Fuels- Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Alternative Fuels (Engine Controls)

2

Is DTC P0602 set?

Go to Step 3

Go to Step 5

3

Program the alternative fuels ECM.

Does DTC P0602 reset?

Go to Step 4

Go to Step 7

4

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

Does DTC P0602 reset?

Go to Step 5

Go to Step 7

5
  1. Test for proper power and ground supply to the alternative fuels ECM.
  2. Inspect for proper terminal contact at the alternative fuels ECM connector. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems in the C/K Pickup Service Manual.

Did you find and correct the condition?

Go to Step 7

Go to Step 6

6

Replace the alternative fuels ECM. Refer to Alternative Fuels Engine Control Module Replacement .

Did you complete the replacement?

Go to Step 7

--

7
  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.

Does the DTC run and pass?

Go to Step 8

Go to Step 2

8

With a scan tool, observe the stored information, Capture Info.

Does the scan tool display any DTCs that you have not diagnosed?

Go to Diagnostic Trouble Code (DTC) List

System OK