GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2006 🢒 Allure 🢒 Restraints 🢒 SIR 🢒 DTC P1640, P1650, or P1660

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 P1640: Control Module Output A Circuit

DTC P1650: Control Module Output B Circuit

DTC P1660: Control Module Output C Circuit

Circuit/System Description

The output driver module (ODM) is a control chip inside of the powertrain control module (PCM). The PCM contains multiple ODMs. ODMs provide grounded output control of devices. Each ODM output has an internal feedback circuit that connects to the PCM microprocessor. The PCM monitors voltage through the ignition 1 voltage circuit. Excessive voltage or current may cause damage to the PCM.

Conditions for Running the DTC
    • The ignition is ON.
    • The system voltage is between 9-11 volts.

Conditions for Setting the DTC
    • The PCM has detected a voltage greater than 26.5 volts.
    • Excessive current is detected on any circuit to the ODM.
    • The above conditions are present for 30 seconds.

Action Taken When the DTC Sets

DTC P1640, P1650, and P1660 are type B DTCs.

Conditions for Clearing the DTC

DTC P1640, P1650, and P1660 are type B DTCs.

Diagnostic Aids

A condition with the charging system may cause this DTC to set. Refer to Charging System Test .

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

    •  Powertrain Control Module Connector End Views
    •  Engine Controls 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

    •  Scan Tool Data List
    •  Scan Tool Output Controls

Circuit/System Verification

With the ignition ON, observe the Output Driver Status with a scan tool. All parameters should indicate OK or no fault present.

Circuit/System Testing
  1. Observe the scan tool for any other DTCs.
    2. ⇒If DTC P0560 is also set, refer to DTC P0560 to repair the charging system.
  2. Observe the Output Driver Status with a scan tool.
    3. ⇒If any parameter does NOT indicate OK, test for a short to voltage on the control circuit of the component that indicated a fault.
    ⇒If all circuits test OK replace the PCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for control module replacement, programming, and setup