Instrument Panel Displays

CIRCUIT OPERATION

BRAKE Indicator (IPC)
The BRAKE Indicator is used to warn the driver of conditions in the brake system that could cause reduced braking ability or the parking brake is not fully released.

The BRAKE Indicator is powered by ignition 3 through CKT 250 at terminal C14 of the IPC. The BRAKE Indicator is controlled by the Park Brake Switch, EBTCM and the controller in the IPC. The following conditions will cause the BRAKE Indicator to turn on:
^ The IPC controller momentarily turns on the Indicator at key-on for a bulb check.
^ The parking brake is not fully released. The Park Brake Switch grounds the Indicator through CKT 852.
^ Low brake fluid. The Low Brake Fluid Switch grounds BCM terminal 1D2 when there is low brake fluid. The BCM then commands the IPC to turn on the BRAKE Indicator through the UART Data Line.
^ Antilock Brake Pressure Valve and EBTCM errors. The EBTCM grounds the Indicator through CKT 852.

CHECK INFO CENTER Indicator
The CHECK INFO CENTER Indicator is powered by switched battery within the IPC. The Indicator is controlled by the IPC and the BCM. The IPC controller momentarily grounds the Indicator at key-on for a bulb check. The BCM commands the Indicator on through the UART Data Line to alert the driver that a message is being displayed on the DIG that requires attention.

CRUISE Indicator (Analog Cluster)
The CRUISE Indicator is controlled by the IPC controller and the PCM. The IPC controller momentarily grounds the Indicator at key-on for a bulb check. The Indicator is commanded on through the UART Data Line whenever the PCM indicates Cruise Control is engaged.

FASTEN BELTS Indicator
The Chime Module controls the Fasten Belts Indicator by applying voltage to the Indicator at key-on for 4 to 8 seconds through CKT 237 at IPC terminal C7. The Indicator is grounded through CKT 804 at IPC terminal C9.

HAZARD Indicator (Analog Cluster)
The BCM commands the Hazard Indicator on and off through the UART Data Line. During Hazard Light operation the BCM monitors the rate at which the lights are being turned on and off at terminal 3D3 (the turn signal rate feedback input). The BCM then commands the Hazard Indicator on and off at the same rate through the UART Data Line.

HI BEAM Indicator
The BCM commands the IPC to turn on the Hi Beam Indicator through the UART Data Line whenever the Hi Beams are on.

INFL REST Indicator
The INFL REST Indicator is powered by ignition 1 through CKT 139 at IPC terminal C12. The DERM controls the Indicator by grounding CKT 358.

OIL PRESS Indicator
The OIL PRESS Indicator is powered by ignition 3 through CKT 250 at terminal C14 of the IPC. The OIL PRESS Indicator is controlled by the IPC and the BCM. The IPC controller grounds the Indicator at key-on and keeps the Indicator grounded until the engine is running and engine oil pressure monitored by the BCM is OK. The BCM commands the Indicator on through the UART Data Line when no voltage is applied to BCM terminal 3D4 (the oil pressure sensor input) while the engine is running.

SERVICE ENGINE SOON Indicator
The SERVICE ENGINE SOON Indicator is powered by ignition 3 through CKT 250 at terminal C14 of the IPC. The Indicator is controlled by the PCM through CKT 419. The PCM flashes the Indicator very quickly at key-on for a bulb check. The PCM also grounds the Indicator when PCM trouble codes are set.

STOP ENGINE TEMP Indicator
The STOP ENGINE TEMP Indicator is powered by ignition 3 through CKT 250 at terminal C14 of the IPC. The Indicator is controlled by the IPC and the PCM. The IPC controller momentarily grounds the Indicator at key-on for a bulb check. The PCM monitors coolant temperature through the Engine Coolant Temperature Sensor. When the coolant temperature exceeds 131° C (270° F) the PCM grounds CKT 37 at terminal 3E3 (the stop engine temp output).

TEMP Indicator
The TEMP Indicator is powered by Ignition 3 through CKT 250 at terminal C14 of the IPC. The Indicator is controlled by the IPC and the PCM. The IPC controller momentarily grounds the Indicator at key-on for a bulb check. The PCM monitors coolant temperature through the Engine Coolant Temperature Sensor. When the engine is running and coolant temperature exceeds 125° C (257° F) the Indicator is commanded on through the UART Data Line. The Indicator is commanded off when coolant temperature falls below 120° C (248° F).

THEFT SYSTEM ARMED Indicator
The THEFT SYSTEM ARMED Indicator is powered by battery within the IPC. The Indicator is controlled by the Pass-Key Decoder Module and the Theft Deterrent Module by grounding CKT 264.

TRAC CNTRL Indicator
The TRAC CNTRL Indicator is powered by Ignition 3 through CKT 250 at terminal C14 of the IPC. The Indicator is controlled by the IPC and the EBTCM. The IPC controller momentarily grounds the Indicator at key-on for a bulb test, The Indicator is also commanded on through the UART Data Line whenever the EBTCM is controlling the front wheels during traction control mode.

Turn Indicator
The BCM commands the Turn Indicator on and off through the UART Data Line. During Turn Light operation the BCM monitors the rate at which the lights are being turned on and off at terminal 3D3 (the turn signal rate feedback input). The BCM then commands the Turn Indicator on and off at the same rate through the UART Data Line.

VOLTS Indicator (Digital Cluster)
The VOLTS Indicator is powered by ignition 3 through CKT 250 at terminal C14 of the IPC. The Indicator is controlled by the IPC and the BCM. The IPC controller momentarily grounds the Indicator at key-on for a bulb test. The BCM monitors the L and F terminals of the Generator to detect charging system faults. The BCM commands the Indicator on through the UART Data Line when a charging fault is detected.

Fuel Gage
The Fuel Gage uses a three terminal Fuel Level Sensor. One terminal is tied to ground, one terminal is tied to ignition voltage, and the third terminal is the sensing line which is tied to the BCM at terminal 2B7 (the fuel level sensor input). If the fuel tank is full, the full tank float moves the sensing line (CKT 30) close to battery voltage. As fuel is consumed the full tank float moves the sensing line voltage towards 0 volts. The BCM compares the fuel level sensor input voltage with the ignition 1 input at BCM terminal 3D1 so that changes in system voltage do not affect the accuracy of the Fuel Gage. The BCM then changes this analog signal to a digital signal and sends it through the UART Data Line to the IPC.

Oil Pressure Gage
The BCM monitors oil pressure at terminal 2B9 through the Oil Pressure Sensor. This analog voltage is converted to a digital signal and sent to the IPC through the UART Data Line.

Speedometer, Odometer and Trip Odometer
The Vehicle Speed Sensor sends electrical pulses to the PCM at the rate of 24,305 pulses per mile. The PCM buffers this signal and sends it to the IPC at a rate of 4,000 pulses per mile through CKT 818. The IPC drives the speedometer based on this signal. The analog cluster has a stepper motor that drives the season and trip odometer in response to the speed signal from the PCM. The digital cluster receives season and trip odometer information through the UART Data Line from the BCM.

Tachometer
The Ignition Control Module outputs engine RPM to the IPC through CKT 121. The IPC processes this signal and displays the engine RPM on the Tachometer.

Temperature Gage
The PCM monitors engine coolant temperature through the Engine Coolant Temperature Sensor at terminal 1B5. The PCM converts this analog signal to a digital signal. The IPC receives temperature information through the UART Data Line.

Volts Gage (Analog Cluster)
The BCM monitors system voltage through CKT 139 at terminal 3D1 (the ignition 1 input). The BCM converts this analog voltage to a digital signal and sends it through the UART Data Line to the IPC.

Driver Information Center
The Driver Information Center (DIC) is a 20 character dot-matrix liquid crystal display with control buttons. All of the DIC control buttons request information through the UART Data Line when pressed except for the Time/Temp Switch. The Time/Temp Switch request is sent to the BCM through CKT 891 when the switch is depressed. Pressing the Time/Temp Switch grounds terminal 2A5 of the BCM (the time/temp switch input) through CKT 891. The BCM sends the requested information to the DIC through the UART Data Line for display. Also vehicle status messages are sent to the DIC from the BCM for display through the UART Data Line. The vehicle status messages remain on display until they are acknowledged by the driver or the condition is corrected. DIC vehicle status messages are acknowledged by pressing any DIC button.