GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2006 🢒 Envoy - 2WD 🢒 DTC 🢒 DTC P0601, P0602, P0603, P0604, P0605, P0606, P0607, P060E, P1600, P1621, P1627, P1681, P1683, or P2610

Description

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

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC P0601 Control Module Read Only Memory (ROM)
    • DTC P0602 Control Module Not Programmed
    • DTC P0603 Control Module Long Term Memory Reset
    • DTC P0604 Control Module Random Access Memory (RAM)
    • DTC P0606 Control Module Internal Performance
    • DTC P0607 Control Module Performance
    • DTC P060E Control Module Throttle Position (TP) System Performance
    • DTC P1621 Control Module Long Term Memory Performance
    • DTC P1683 Control Module Ignition OFF Timer Performance
    • DTC P2610 Control Module Ignition OFF Timer Performance

Conditions for Running the DTC

P0601

    • The ignition switch is in the Run or the Crank position.
    • DTC P0601 runs continuously when the above condition is met.

P0602

    • The ignition switch is in the ON position.
    • DTC P0602 runs continuously when the above condition is met.

P0603

    • The ignition switch is in the ON position.
    • DTC P0603 runs continuously when the above condition is met.

P0604

    • The ignition switch is in the Run or the Crank position.
    • DTC P0604 runs continuously when the above condition is met.

P0606

    • The ignition switch is in the Unlock, Accessory, Run, or Crank position.
    • The system voltage is more than 5.23 volts.
    • DTC P0606 runs continuously when the above conditions are met.

P0607

    • The ignition switch is in the ON position.
    • DTC P0607 runs continuously when the above condition is met.

P060E

    • DTCs P0601, P0602, P0603, P0604, P0606, P0607, P1621, P2610 are not set.
    • The system voltage is more than 5.23 volts.
    • The ignition switch is in the Unlock, Accessory, or Run position.
    • The above conditions are met for more than one second.
    • DTC P060E runs continuously when the above conditions are met.

P1621

    • The ignition switch is in the ON position.
    • DTC P1621 runs continuously when the above conditions are met.

P2610

    • The ignition switch is in the ON position.
    • The intake air temperature (IAT) is between -7 and +75°C (+20 and +167°F).
    • The above conditions are met for more than 14 seconds.
    • The ECM is powered down.
    • DTC P2610 runs continuously when the above conditions are met.

Conditions for Setting the DTC

The ECM detects an internal failure or incomplete programming for more than 14 seconds.

Action Taken When the DTC Sets

P0601, P0602, P0603, P0604, P0606, P060E and P1621

    • The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
    • The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

P2610

    • The control module illuminates the MIL on the second consecutive ignition cycle that the diagnostic runs and fails.
    • The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

P0607

    • The control module stores the DTC information into memory when the diagnostic runs and fails.
    • The MIL will not illuminate.
    • The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
    • The driver information center (DIC), if equipped, may display a message.

Conditions for Clearing the MIL/DTCs

P0601, P0602, P0603, P0604, P0606, P060E, P1621, and P2610

    • The control module turns OFF the MIL after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
    • A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
    • Clear the MIL and the DTC with a scan tool.

P0607

    • A current DTC Last Test Failed clears when the diagnostic runs and passes.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
    • Clear the DTC with a scan tool.

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 - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Is DTC P0602 set?

Go to Step 3

Go to Step 5

3

Program the engine control module (ECM). Refer to Service Programming System (SPS) .

Does DTC P0602 reset?

Go to Step 4

Go to Step 7

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

Does DTC P0602 reset?

Go to Step 5

Go to Step 7

5

Test all voltage and ground inputs to the ECM for an open circuit or high resistance. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 7

Go to Step 6

6

Replace the ECM. Refer to Control Module References for replacement, setup, and programming.

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.

Did the DTC fail this ignition?

Go to Step 2

Go to Step 8

8

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

Go to Diagnostic Trouble Code (DTC) List - Vehicle

System OK