Instrument Panel Cluster

INSTRUMENT PANEL CLUSTER (IPC)

NOTICE: The IPC is an Electrostatic Discharge (ESD) Sensitive Component. Follow handling and measuring precautions.

The IPC used in this vehicle consists of either a digital cluster or an analog (hybrid) cluster. Both versions of the cluster contain controls which permit the driver to monitor operation and/or control vehicle systems while maintaining excellent drivability. A list of IPC functions follows (not all of these functions are available outside the diagnostic mode):
^ Alternator Control
^ Brake Fluid Level Switch
^ Coolant Level Switch
^ Driver Information Center Display
* Diagnostic Trouble Codes
* Warning/Status Messages
^ Electronic PRNDL
^ English/Metric Display
^ Exterior Lighting
^ Fuel Data Center (Digital IPC only)
^ Fuel Door release
^ Heated Windshield
^ HVAC Controls (Digital IPC only)
^ Ignition
^ Indicators
^ Interior Lighting
^ PASS-Key II
^ Steering Wheel Controls
^ Trunk release
^ Turn Signals
^ Wipers
^ Key in Ignition Switch

The IPC has the capability to diagnose malfunctions in the sensors, input switches, components and systems it controls or communicates with. When the IPC, or another microprocessor-controlled module, detects a malfunction, it may turn on an IPC indicator or request/display a message to the Driver Information Center to alert the driver that a malfunction has occurred. Some indicator lamps and IPC messages have dual controls.

In addition to the IPC, this vehicle contains other modules with microprocessors to control various vehicle functions based on sensors, switch inputs and Class 2 serial data communication with the other module microprocessors. A list of other vehicle microprocessor subsystems and where details of basic operation, diagnosis and service are located follows:
Powertrain Control
Heating, Ventilation and Air Conditioning
Body Control
Radio
Cellular Telephone
Suspension
Electronic Brake and Traction Control
Remote Keyless Entry
Memory Seats

IPC Functions
The IPC contains two microprocessors as part of the Instrument Panel Assembly. The IPC can recognize operational malfunctions, alert the driver through indicators or Driver Information Center messages and store DTCs which identify malfunction areas for the technician. Refer to ON-BOARD DIAGNOSTIC OPERATION for more information on using the diagnostic function of the IPC. In order to perform all of these functions, the IPC microprocessor has its own inputs, outputs and program software.

IPC EPROM
The IPC contains a Flash EPROM (Electrically Programmable Read Only Memory) that contains the program information used by the IPC to control and display vehicle parameters. It is crucial that all information requested by the authorized service center, if obtaining a replacement IPC, be correct so they can supply the correct version of software for the vehicle you are working on. The EPROM will retain its data if battery power is lost. The Flash EPROM can NOT be serviced separately.

IPC EEPROM
The IPC contains a data storage unit which can save critical data even when battery power is removed. This unit, the Electrically Erasable Programmable Read Only Memory (EEPROM) is used by the IPC to store odometer readings, Options settings, manufacturing information and the Vehicle Identification Number (VIN). The EEPROM is soldered into the IPC and can not be serviced separately. The EEPROM will retain its data if battery power is lost.

IPC Programming flowing Replacement
Since data contained in the EEPROM is specific to the vehicle that the IPC is in, the EEPROM must be reprogrammed by the authorized service center if the IPC is replaced. It is crucial that all information requested by the authorized service center be correct so they can program the correct data for the vehicle you are working on. When the IPC is received from the authorized service center, it will contain the same IPC override information as the removed IPC as well as the correct VIN.

The replacement IPC will is configured to learn the PASS-key II resistor pellet value of the vehicle. The Theft Module Re-learn must be performed before the vehicle will start:

Theft Module Re-learn procedure with a GM Service Programming System SPS T50 or T60.
1. Using an T50 or T60 enter Service Programming System (SPS).
2. Select Theft Module Re4eam.
3. Follow the instructions displayed on the T50 or T60.
4. Verify the repair.

Theft Module Re-learn procedure without a T50 or T60.
1. Cycle the Ignition Switch to the "RUN" position.
2. Wait a minimum of 10 minutes, cycle the Ignition Switch to the "OFF" position.
3. Cycle the Ignition Switch to the "RUN" position.
4. Wait a minimum of 10 minutes, cycle the Ignition Switch to the "OFF" position.
5. Cycle the Ignition Switch to the "RUN" position.
6. Wait a minimum of 10 minutes, cycle the Ignition Switch to the "OFF" position.
7. Verify the repair.

Analog and Digital IPCs
The gage portion of the IPC is available in analog or digital versions. Both types of IPCs are discussed in the following paragraphs, followed by parameters specific to the analog or digital IPC.

NOTICE: Analog and Digital IPCs are not interchangeable. Replace an IPC only with one of similar type.

All gages may be toggled between English and Metric units by pressing the "ENG/MET" button on Digital or by pressing "INFO" button until Eng/Met Reset is displayed, then pressing "INFO RESET" on the Analog IPC.

ODOMETERS
Season and trip odometer displays are provided. All calculations for these displays are made in the IPC based on the vehicle speed input received from the PCM.

Season Odometer
The season odometer displays the total accumulated miles/km of the vehicle. This value is permanently stored in the EEPROM of the IPC. If an odometer malfunction occurs or if the IPC must be replaced, an authorized Delco service center must be contacted to program proper vehicle specifics (including mileage) for the IPC.

NOTE: When replacing a speedometer/odometer assembly, federal law requires the odometer reading of the replacement unit to be set to register the same mileage as the prior odometer. If the same mileage cannot be set, the law requires that the replacement odometer be set to zero and a label be installed on the driver's door frame to show the previous odometer reading and the date of replacement.

Trip Odometer
The trip odometer displays accumulated mileage/km to tenths of a mile/km since last reset. The Trip odometer may be reset by holding the "Trip Set" button for more than one (1) second. If the "Trip Set" button is not used, the "roll-over" or automatic set point of the trip odometer is dependent on the country for which the vehicle was built.

United States vehicles will "roll-over" at 999.9 miles. If operating in metric mode (i.e. kilometers are being displayed) the trip odometer will "roll-over" at 1609.1 km (999.9 miles).

Canadian and export vehicles will "roll-over" at 1999.9 kilometers. If operating in English mode (i.e. miles are being displayed) the trip odometer will "roll-over" at 1242.6 miles (1999.9 km).

DE-ICE (Optional)
Turns on the Heated Windshield heating element.

DE FOG
Turns on the Defog climate control mode (disable recirc mode, normal and cold purge modes, A/C purge mode and enable checking the A/C compressor criteria if previously in ECON mode.

REAR DEFOG
Rear Defog activates the heat grid in the rear window. The driver activates the feature via the button on the IPC. The IPC makes a Class 2 Serial Data request to the PZM to turn on the Rear Defog. The PZM turns "ON" the Rear Defog Relay and reports the status to the IPC. Rear Defog is not available when On-Board Diagnostics are enabled, since the Heater and A/C Programmer and the PZM are not communicating.

DIMMING
The IPC displays are dimmable with parklamps or headlamps on, via the headlamp switch. Only the indicators, turn signals, and hi beam annunciators are non-dimmable. The IPC monitors the Dimming Potentiometer, Parklamp, Headlamp and Twilight Sentinel inputs to determine if dimming should be active and, if active, at what level.

The IPC generates three different pulse-width modulated (PWM) outputs which correlate to the requested dimming level from the dimming potentiometer. The IPC also determines the appropriate vacuum fluorescent (VF) dimming level and sends this information to the IRC, CCP and Cellular Telephone (if applicable) via the Class 2 serial data bus.

The IPC also supplies a 16-volt power feed to the IRC for VF intensity stabilization. This is typically only available when the ignition switch is in "UNLOCK" or "RUN," but may be "ON" when the Driver Information Center is active. See the description for Dimming Inoperative/Improper".

DISPLAY ON/OFF (DIGITAL IPC ONLY)
The "DISPLAY ON/OFF" feature allows the driver to turn off a portion of the IPC displays. Pressing "DISPLAY ON/OFF" will turn "OFF". all IPC Vacuum Fluorescent displays except for speedometer, gear position and indicators. Pressing "DISPLAY ON/OFF" a second time will turn all displays back "ON."

Certain buttons on the IPC (i.e. "INFORMATION," "RESET," "TIMER", Electronic Climate Control or Fuel Data Center buttons will cause only certain areas of the IPC to be turned "ON." These displays may or may not automatically turn "OFF" after a short period. Depressing the "TRIP SET" button will cause the IPC to illuminate all displays. Additionally, if a condition which would produce a driver warning message occurs or if fuel level falls below 4 gallons, all displays will turn "ON" and a message will be displayed.

Driver information may be recalled during display "OFF" operation by pressing the information button. This will cause only the Driver Information Center portion of the blanked displays to turn "ON" and remain "ON."

FUEL LEVEL
Fuel Level is read from the fuel level sender by the PZM and sent to the IPC via Class 2 serial data bus. The IPC then displays the fuel level. The fuel gage displays the current fuel level in whole gallons/liters. When the IPC reads above 18.5 gallons the display will read "F." Readings between 18.5 and 2.5 gallons will be displayed as whole gallon numbers. When the level reaches 2.5 gallons the display will read "E." When the level reaches 4.5 liters (1.2 gallons) the "E" will flash and a "FUEL LEVEL VERY LOW" message will appear on the Driver Information Center.

Analog IPC Only Functions
The analog gage package provides swing needle readouts for vehicle speed, coolant temperature, fuel level, and engine RPM. There are no HVAC controls on the analog IPC. A Climate Control Panel (CCP) is furnished with models containing the analog IPC.

VEHICLE SPEED
Vehicle speed is obtained over a discrete input from the Powertrain Control Module (PCM). This vehicle speed pulse train is expressed as 4000 pulses per mile.

COOLANT TEMPERATURE
Coolant temperature is broadcast from the PCM via Class 2 serial data to the IPC. The IPC compares the temperature data with a sixteen-point calibration table to determine needle deflection. A smoothing filter is used to secure a continuous response.

FUEL LEVEL
Fuel Level is read from the fuel level sender by the PZM and sent to the IPC via the Class 2 serial data bus. The IPC then displays the fuel level. The fuel level is monitored and when the level reaches 1.2 gallons a "FUEL LEVEL VERY LOW" message will appear on the Driver Information Center. The "FUEL LEVEL VERY LOW" message may be suppressed by setting the appropriate bit in tile Option Byte.

ENGINE RPM
The Engine RPM (tachometer) gage is driven by a discrete input from the PCM.

Digital IPC Only Functions
The digital gage package provides numeric readouts for vehicle speed, range, fuel economy (MPG), odometers, outside temperature, HVAC temperature setting and mode, and fuel level. Engine RPM is available through the Driver Information Center display, described below.

OUTSIDE AIR TEMPERATURE (Digital IPC only)
Outside air temperature is sensed by a thermistor behind the grill. The thermistor resistance is sensed by the Heater and A/C Programmer (ACM) and the data is transmitted to the IPC via Class 2 serial data bus. The data is converted to the appropriate units (English F°/Metric C°) and displayed.

OFF
Turns off all climate control functions except Rear Defog and De-ice, if equipped. Outside temperature and set temperature are still displayed.

SET TEMPERATURE
Set temperature is the temperature desired by the driver. It is controlled via the Warmer (red) and Cooler (blue) buttons on the Climate Control Center of the IPC. The IPC monitors these inputs and sends the Heater and A/C Programmer the actual desired set temperature.

RECIRC
Controls the recirculation door to either allow fresh air circulation through the vehicle when open, or use the fan to recirculate interior air with the door closed.

AUTO/ECON
Auto mode automatically selects the appropriate solenoids, blower speed and A/C clutch to control the climate. ECON mode disables the A/C clutch and forced recirculation (if enabled). The engine cooling fans will not respond to a A/C Highside Temperature condition in the economy mode.

BLOWER SPEED
Blower speed controls the amount of air flow through the climate control ducts. The driver selects blower speed using the Fan Up/Fan Down rocker switch. The IPC monitors these inputs and sends the Heater and A/C Programmer the actual selected blower speed. Fan speed cycles through the following speeds in a circular fashion:
^ Low
^ Auto Low
^ Auto
^ Auto High
^ High

DEFROST
Selects the defrost climate control mode (disable recirc, enable A/C, Up Air and snow ingestion mode).

VEHICLE SPEED
Vehicle speed is obtained through a discrete input from the PCM. The IPC displays vehicle speed in kilometers (miles) per hour for the entire range of capable speed. flashing vehicle speed display at high speeds indicate vehicle configuration for non-North American application (see diagnosis in this section).

FUEL DATA CENTER
The Fuel Data Center, available only on the digital IPC, provides a digital readout of range, instant fuel economy, and average fuel economy. Calculations are made by the IPC using odometer information and fuel information sent via Class 2 serial data from the PCM.

Vehicle Range
Vehicle Range is displayed as an estimate of expected remaining driving distance with current fuel level. Driving range is based on the fuel in the tank and fuel economy over the last 40 km (25 miles). Because of the required predictions, displayed Range and actual Range may vary. When calculated Range falls below 65 km (40 miles), the range display will read "LO".

Vehicle Range is calculated by the IPC as described below.
Estimated Drivable Range = Distance Traveled/Fuel Used x Scale Factor x Filtered Fuel in Tank

This calculation is based on the last 40 km (25 miles) driven and is an estimate of the drivable range. This calculation cannot be reset by the driver. The data used to calculate range is lost if a battery disconnect has occurred. This portion of the IPC will be dashed if there is a loss of PCM or PZM communications.

Average Fuel Economy (MPG)
Average fuel economy is the '1100km (MPG) obtained since the last reset. Average fuel economy is reset by pressing the "Reset" button when the average fuel economy is being displayed on the Driver Information Center. This portion of the IPC will be dashed if there is a loss of PCM or PZM communications. Average Fuel Economy is calculated by the IPC as described below.

The AVERAGE FUEL ECONOMY can be displayed on the Fuel Data Center by pressing the "AVG" button or it can be displayed on the Driver Information Center by pressing the "INFORMATION" button until the display reads "AVG" L/100km" (AVG MPG).

The value for Average Fuel Economy will be reset when AVERAGE FUEL ECONOMY is displayed on the Driver Information and the RESET button is pushed for greater than 1 second. Average Fuel Economy (AFE) is computed: AFE = (Trip Distance)/(Trip Fuel Used) x Scale Factor

Where "Trip" is the distance traveled or fuel used since the last reset. Fuel used data is received from the PCM and Trip Distance is received by the dedicated vehicle speed input.

Instantaneous Fuel Economy (IFE)
The "INST" and "AVG" buttons are used to toggle between average and instantaneous fuel economy displays. Instantaneous Fuel Economy (IFE) is based on the previous few seconds of driving as follows:

IFE - Distance I Fuel Used x Scale Factor

Fuel data is received from the PCM. Distance is determined from the discrete vehicle speed input to the IPC. This parameter cannot be reset by the driver. This portion of the IPC will be dashed if there is a loss of PCM or PZM communications.

CLIMATE CONTROL CENTER
The Climate Control Center section of the digital IPC provides current outside temperature, set temperature, mode, blower speed, de-ice (optional) and rear defog information. Each of these areas and their impact to the IPC is discussed below. No separate climate control panel is installed with a digital IPC.