GM Service Manual Online
For 1990-2009 cars only

The Instrument Panel Cluster (IPC) serves as the primary display unit for systems that require display functions. The IPC is capable of displaying system information and driver warning/status messages by using three different technologies:

    • Vacuum Fluorescent (VF) lighting
    • Ultraviolet lighting
    • Air core gauges

Located on the IPC is a 20-character vacuum florescent display referred to as the Driver Information Center (DIC). The DIC is used to display driver selectable information and warning/status messages. The DIC switches are located on the IPC and can be used to access any of the modes listed. For example, oil pressure can be displayed by pressing the GAGE button, and personalized option can be displayed by pressing the OPTIONS button. The following information can be assessed through the IPC display by selecting the following DIC switches:

    • FUEL
       - Average
       - Instantaneous
       - Range
    • GAGE
       - Oil pressure
       - Oil temperature
       - Coolant temperature
       - Transmission temperature (Auto trans only)
       - Battery voltage
       - Front tire pressure
       - Rear tire pressure
    • TRIP
       - Odometer
       - Trip A
       - Trip B
       - Elapse time
       - Average speed
       - Oil life remaining
    • OPTIONS
       - Twilight
       - Universal Theft Deterrent (UTD) functions
       - Lock functions (passive and auto)
       - Approach lighting
       - Seat easy entry
       - Languages
       - Blank display (fob and tire training mode)
    • E/M
       - English
       - Metric
    • RESET
       - Used to Acknowledge IPC Messages
       - Reset Trip Odometer Functions
       - Start/Stop Elapsed Time
       - Reset Average Speed
       - Reset Oil Life Monitor System
       - Reset Fuel Economy Functions
       - Customize Vehicle Electrical Functions
       - Remote Function Actuation (RFA) programming
       - Change personalized options

The IPC is also responsible for indicator illumination and chime functions. Some indicators are directly controlled by the IPC and others are controlled by a dedicated circuit to the IPC. The IPC controlled indicators are illuminated when a message is received on the serial data line to perform this function. Indicators that are illuminated by a dedicated wire to the IPC are controlled directly by other systems which provide all control functions. The IPC controls all chime functions and is able to determine what indicator is associated with a chime. The chime is integrated within the IPC and is not serviced separately.

Instrument Panel Cluster


Object Number: 173135  Size: MF

IPC System Functions

The Instrument Panel Cluster (IPC) is capable of preforming the following functions:

    • Gauge display
       - Speedometer
       - Fuel gauge
       - Tachometer
       - Coolant temperature
       - Oil pressure
       - Voltage
    • Indicator control
    • Ambient light sensor processing
    • Head Up Display (HUD)
    • Chime functions
    • Dimming control level
    • Oil temperature processing
    • Switch illumination
    • Warning/Status message display
    • Driver Information Center (DIC) functions

Wake-Up/Asleep States

Wake-Ups are signals that will turn the IPC ON and cause it to begin active control and/or monitoring. The IPC is asleep when it has stopped control or monitoring and has become idle again. The IPC has the ability to detect wake-up inputs when in the sleep state. Wake-ups input monitoring is needed to allow the IPC determine when to wake-up and begin active monitoring and control of vehicle functions. The IPC will enter a wake-up state under any of the following conditions:

    • Any activity on the serial data line
    • Headlamp switch ON.
    • Courtesy lamps ON.
    • Power mode message received from the Body Control Module (BCM)
    • Battery was disconnected then reconnected
    • Ignition is turned ON

The IPC has a low power or sleep state. This state is intended to reduce parasitic load during a period when no control functions are needed. The IPC will enter a sleep state when all the following conditions are met:

    • No Activity on the serial data line for approximately 10 seconds.
    • Ignition switch is in the OFF position
    • Headlamps are OFF
    • Courtesy lamps OFF
    • Power mode message was not received from the BCM
    • SECURITY indicator is OFF

If all these conditions are met the IPC will enter a low power or sleep condition. However, the IPC will still be able to monitor wake-up inputs and as well as any activity on the serial data line to determine when to enter a wake-up state.