DTC P0602 Control Module Not Programmed. GMC Truck GMC K Sierra

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 1999 🢒 GMC K Sierra - 4WD 🢒 Engine 🢒 Engine Controls - 4.8L, 5.3L, and 6.0L 🢒 DTC P0602 Control Module Not Programmed

Circuit Description

This DTC indicates that the PCM internal EEPROM is not flashed with any vehicle software. If you install a service PCM and do not flash the EEPROM, the engine will not run. This DTC indicates that an un-flashed PCM causes the engine cranks but will not run situation.

Conditions for Running the DTC

The ignition switch is in the RUN position.

Conditions for Setting the DTC

No software data is present in the PCM.

Action Taken When the DTC Sets

•	The PCM illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.

•	The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Freeze Frame and/or Failure Records.

Conditions for Clearing the MIL/DTC

•	The PCM turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.

•	A last test failed, or current DTC, clears when the diagnostic runs and does not fail.

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

•	Use a scan tool in order to clear the MIL and the DTC.

Diagnostic Aids

Important: Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing/replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent water intrusion into the PCM.

For an intermittent, refer to Symptoms .

Test Description

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

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 download is correct for the PCM being flashed. If everything is OK, and a second attempt fails, the PCM is faulty.

Step	Action	Value(s)	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	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	Verify that the equipment being used is functioning properly and that all the cable connections are clean and tight. Attempt to flash the PCM again. Does DTC P0602 reset?	--	Go to Step 4	Go to Step 5
4	Important:: Program the replacement PCM. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Is the action complete?	--	Go to Step 5	--
5	Select the Diagnostic Trouble Code (DTC) option and the Clear DTC Information option using the scan tool. Idle the engine at the normal operating temperature. Select the Diagnostic Trouble Code (DTC) option and the Specific DTC option, then enter the DTC number using the scan tool. Operate the vehicle within the Conditions for Running the 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	Select the Capture Info option and the Review Info option using the scan tool. Does the scan tool display any DTCs that you have not diagnosed?	--	Go to the applicable DTC table	System OK