GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2007 🢒 Savana 🢒 Engine 🢒 Engine Controls and Fuel - 6.6L (LBZ and LLY) 🢒 DTC P0601, P0602, P0603, P0604, P0605, P0606, P0607, P060B, P061C, P062C, P062F, or P2610

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC P0602: Control Module Not Programmed

DTC P0606: Control Module Internal Performance

DTC P060B: Control Module Analog to Digital Performance

DTC P061C: Control Module Engine Speed Performance

DTC P062C: Control Module Vehicle Speed Performance

DTC P062F: Control Module Long Term Memory Performance

DTC P2610: Control Module Ignition Off Timer Performance

Circuit/System Description

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

The ECM monitors its ability to read and write to the memory. It also monitors a timing function.

Conditions for Running the DTC

P0602

The following conditions must be met:

    • The ignition switch is ON.
    • The controller is identified as a service replacement ECM.

P0606

The following conditions must be met:

    • The ignition switch is in Run or Crank.
    • The power take-off (PTO) is inactive.
    • The cruise control is inactive.

P060B

    • The engine speed is more than 650 RPM.
    • The ECM is powered up.

P061C

    • The ignition is ON.
    • The engine speed is less than 1,300 RPM.

P062C

The ignition is ON.

P062F

The ignition is ON.

P2610

The ECM is powered up.

Conditions for Setting the DTC

P0602

    • The ECM has not been programmed at Key On and Engine Off for 0.1 second.
    • This diagnostic runs continuously.

P0606

    • The ECM detects a microprocessor undervoltage or overvoltage condition.
        OR
    • The ECM detects an internal bus communication error.
        OR
    • The ECM detects an internal clock error.
        OR
    • The ECM detects an internal injector control error.
    • All tests run in less than 1 second.
    • This DTC runs continuously.

P060B

    • The ECM detects an incorrect internal analog/digital (A/D) signal for less than 1 second.
    • This DTC runs continuously.

P061C

    • The ECM detects that there is a difference between the CKP engine speed and the calculated engine speed of more than 320 RPM for less than 1 second.
    • This diagnostic runs continuously.

P062C

    • The ECM detects a fault in the ship that calculates redundant vehicle speed for more than 1 second.
    • This DTC runs continuously.

P062F

    • The ECM did not complete the last electronic erasable programmable read only memory (EEPROM) write event during the last ECM power down.
    • This diagnostic runs once per ignition cycle at power up.

P2610

    • The ignition off-timer is less than 0 second.
        OR
    • The ignition off-timer is less than 5 seconds for more than 10 seconds.
        OR
    • The ignition off-timer is unchanged for 60 seconds.
        OR
    • The ignition off-timer is not incrementing in 1 second intervals.

Action Taken When the DTC Sets
    • DTCs P0602, P0606, P060B, P061C, P062C and P062F are Type A DTCs.
    • DTC P2610 is a Type B DTC.
    • If the diagnostic reports a failure, the control module uses a cold start model based on the engine coolant temperature and intake air temperature at engine start-up. Using the cold start model ensures that the control module is able to determine how much time has elapsed between ignition cycles.

Conditions for Clearing the MIL/DTC
    • DTCs P0602, P0606, P060B, P061C, P062C and P062F are Type A DTCs.
    • DTC P2610 is a Type B DTC.

Circuit/System Testing
  1. Observe the DTCs with the scan tool.
    2. ⇒If DTC P0602 or P062F is set, attempt to program the ECM before replacing the ECM. Refer to Service Programming System (SPS) .
    ⇒If DTC P0606 was set while performing SPS Programming, clear the DTCs and exit the diagnostic.
    ⇒If DTC P0606 was set with DTC P0851 or P0852, diagnose DTC P0851 or P0852 first. Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
  2. Test the voltage and ground circuits to the control module for the following:
    3. • A short
    • An open
    • High resistance

    Important: DTC P2610 can be set with a loss of battery voltage to the ECM with the ignition ON. The ignition must be in the OFF position before disconnecting the ECM.

  3. If DTC P2610 is set, turn the ignition OFF and then completely disconnect the ECM harness connectors from the ECM for at least 1 minute before clearing the DTC. Reinstall all of the ECM connectors and then attempt to clear codes with the scan tool.
    4. ⇒If DTC P2610 resets after code clear, replace the ECM.
  4. Replace the ECM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, setup, and programming.