GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2009 🢒 HHR 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC P0601-P0606, P062B, P064D, P167A, P167D, P2105, 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 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 P062B: Control Module Fuel Injector Control Performance

DTC P064D: Control Module HO2S 1 System Performance

DTC P167D:  Control Module Ignition Coil Internal Circuit

DTC P2105: Throttle Actuator Control (TAC) System - Forced Engine Shut-down

DTC P2610: Control Module Ignition OFF Timer Performance

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.

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

Conditions for Running the DTCs

P0601

    • The ignition switch is in Run or Crank.
    • The check sum calculation at power-down in the last drive cycle had completely finished.
    • DTC P0601 runs once per ignition cycle when the above condition is met.

P0602

    • The ignition switch is in Run or Crank.
    • DTC P0602 runs once per ignition cycle.

P0603

    • The ignition switch is in Run or Crank.
    • DTC P0603 runs once per ignition cycle.

P0604

    • The ignition switch is in Run or Crank.
    • The read/write test at power-down in the last drive cycle had completely finished.
    • DTC P0604 runs once per ignition cycle when the above condition is met.

P0606

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

P062B

    • The engine is running or cranking.
    • The system voltage is between 8-18.1 V.
    • DTC P062B runs continuously when the above condition is met.

P064D

    • The engine is running or cranking.
    • The system voltage is between 10.7-18.1 V.
    • DTC P064D runs continuously when the above condition is met.

P167D

    • The engine is running or cranking.
    • The engine speed is less than 6,000 RPM.
    • The system voltage is between 9-18.1 V.
    • DTC P167D runs continuously when the above condition is met.

P2105

    • The ignition switch is in Run or Crank.
    • The ECM power-down in the last drive cycle had completely finished.
    • DTC P2105 runs continuously when the above condition is met.

P2610

    • The ECM is powered down.
    • DTC P2610 runs once per ignition cycle.
        OR
    • The ECM is powered up with the ignition switch in the Run or Crank position.
    • The engine OFF timer value is less than or greater than an internal reference counter during an 8-second interval.
    • DTC P2610 runs continuously when the above conditions are met.

Conditions for Setting the DTCs

The ECM detects an internal failure or incomplete programming for more than 10 seconds.

Actions Taken When the DTC Sets
    • DTCs P0601, P0602, P0603, P0604, P0606, P2105 are Type A DTCs.
    • DTCs P062B, P064D, P167D, P2610 are Type B DTCs.

Conditions for Clearing the MIL/DTC
    • DTCs P0601, P0602, P0603, P0604, P0606, P2105 are Type A DTCs.
    • DTCs P062B, P064D, P167D, P2610 are Type B DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing
  1. Observe the DTCs with the scan tool.
    2. ⇒If DTC P0602 is set, attempt to program the ECM before replacing the ECM. Refer to Control Module References.
    ⇒If DTC P0602 resets, replace the ECM.
  2. Test the voltage and ground inputs to the ECM for the following:
    3. • A short
    • An open
    • High resistance
    ⇒If all circuits test normal, replace the ECM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, programming and setup