Principles of Operation (How Does It Work?)

The electronic instrument cluster is operational only when the ignition switch is ON. The electronic vacuum fluorescent displays are powered by a non-repairable internal power supply. The only illumination bulb used, which cannot be installed separately, is for backlighting the transmission range indicator. When the headlamps are turned on, the instrument cluster dims according to the interior lighting control switch position.

The instrument cluster contains digital speedometer/odometer, fuel gauge and engine coolant temperature gauge. The indicator lamp module is housed within the instrument cluster and contains miniature bulb warning indicators for ABS, traction control, brake and hazard. The instrument cluster also contains digital message center display information that is controlled by the message center switch module.

Each time the ignition switch is turned from OFF to ON, the three electronic displays will prove out by momentarily illuminating all of the segments and then turning all display segments off. After prove-out, the three displays will return to normal operation. Prove-out mode indicates that all display segments are operating correctly. After the initial prove-out period with the ignition switch ON, these warning indicators are off with the ignition switch ON (warnings will be on with the ignition switch ON, engine off). The following instrument cluster warning indicators will prove out:
- AIR BAG
- charging system
- CHECK ENGINE
- safety belt
- oil pressure
- fail-safe cooling
- LOW FUEL
- SPEED CONTROL
- CHECK AIR SUSPENSION
- OVERDRIVE OFF
- DOOR AJAR
- LOW WASHER FLUID
- TRUNK AJAR

There are three exceptions to prove-out: The high beam and turn signal indicators will not illuminate during prove-out. In addition, the safety belt, CHECK ENGINE, AIR BAG and oil pressure warning indicators will remain illuminated during the blank portion of prove-out and then go blank at the beginning of, or shortly after, normal instrument cluster display. The charging system warning proves out by illuminating when the ignition switch is turned to RUN, before the engine is started.

Engine Coolant Temperature Gauge
The engine coolant temperature gauge indicates the engine coolant temperature based on the operating resistance range from the engine coolant temperature sender. If the engine coolant temperature is low the sender resistance is high. If the engine coolant temperature is high the sender resistance is low. The engine coolant temperature sender resistance range should be between 200 ohms to 13,000 ohms.

Fuel Gauge
The fuel level is displayed on a digital bar gauge using eight bars top to bottom. Fuel remaining is displayed in the fuel/temperature gauge. For fuel levels greater than 70 liters (18 gal), the letter F (full) is displayed. For fuel levels less than 3 liters (2 gal), the letter E (empty) is displayed. The digital displays are based on varying current flow from the fuel level sensor. The instrument cluster also contains self-diagnostics for the fuel gauge.

Speedometer
The speedometer provides vehicle speed information based on a speed signal from the PCM. The PCM receives the vehicle speed information from the output Shaft Speed Sensor (OSS).

Odometer
The vehicle odometer data is transmitted to the instrument cluster from the PCM. The odometer displays seven digits with the last digit in tenths of a unit. The odometer range is limited by instrument cluster memory space. The S symbol on the odometer indicates that the original odometer mileage is unknown. If the actual mileage can be verified, an authorized repair facility can program a new odometer to reflect the correct mileage. The message ERROR indicates that the instrument cluster cannot read a valid odometer memory from the non-volatile random access memory.

Speed Control
When the speed control system is activated, a signal is supplied to the instrument cluster from the speed control servo, illuminating the SPEED CONTROL indicator.

High Beam
The high beam indicator will illuminate when the multifunction switch is placed in the high beam headlamps ON position or the flash-to-pass position.

LH/RH Turn/Hazard
The LH and/or RH turn indicators will flash when the multifunction switch is placed in the RH or LH turn signal ON position or when the hazard switch is placed in the ON position and the ignition is ON. If the hazard switch is on and the ignition is OFF, only the hazard indicator in the indicator lamp module will flash.

Traction Control
The traction control indicator is located in the indicator lamp module and illuminates when the traction control system is disabled. Information is transmitted to the indicator lamp module through hardwired circuitry from the Anti-theft Brake System/Traction Control (ABS/TC) module.

Warning Indicators

AIR BAG
The air bag warning indicator is controlled by the restraint control module. When starting the vehicle, the air bag warning indicator illuminates and remains lit for six seconds. The indicator only illuminates after starting the vehicle if a Supplemental Restraint System (SRS) malfunction is detected.

Anti-Lock Brakes Warning Indicator
The instrument cluster receives the Anti-lock Brake System (ABS) status message through hardwired circuitry from the anti-lock brake system/traction control (ABS/TC) module. The anti-lock brake system (ABS) warning indicator illuminates when the ABS/TC module detects a fault in the system.

BRAKE System
The BRAKE system warning indicator is located in the indicator lamp module and has a dual function. It illuminates when the parking brake is applied or when a low brake fluid condition exists in the brake master cylinder reservoir. The BRAKE system warning indicator will illuminate when there is a pressure differential between the front and rear brake hydraulic systems.

Charging System
The charging system warning indicator illuminates whenever the generator output is insufficient to maintain battery state of charge or if the generator output is too high. Under normal operation, the indicator goes out after the engine is started and the charging system begins to operate. The charging system indicator is hardwired to the Powertrain Control Module (PCM). When the charging system output is low, the PCM provides a ground path to the instrument cluster and turns on the charging system warning indicator.

LOW FUEL1
The instrument cluster utilizes duel level data that is transmitted through hardwired circuitry from the fuel pump module. The low fuel level warning indicator flashes when approximately one-eighth tank of fuel or less is remaining.

OVERDRIVE OFF
The OVERDRIVE OFF indicator has dual functions. The OVERDRIVE OFF indicator illuminates when the overdrive is turned off. The OVERDRIVE OFF indicator will also flash if a fault is detected in the automatic transmission.

Safety Belt Warning Indicator
The safety belt warning indicator is directly hardwired to the Lighting Control Module (LCM). The LCM controls the safety belt indicator depending on the signal it receives from the safety belt buckle switch. The safety belt warning indicator illuminates when the safety belt is not buckled, closing the safety belt buckle switch.

CHECK ENGINE
The CHECK ENGINE indicator illuminates when a fault condition is detected by the powertrain control module (PCM). The CHECK ENGINE indicator will remain illuminated until the condition is corrected.

Low Oil Pressure Warning
The low oil pressure warning indicator indicates the engine oil pressure status. The instrument cluster is hardwired to the normally open oil pressure switch. With the engine running, the oil pressure switch closes and provides a ground to the instrument cluster and turns off the low oil pressure warning indicator. When oil pressure is low or the engine is not running, the oil pressure switch opens and removes the ground to the instrument cluster turning on the low oil pressure warning indicator.

Fail-Safe Cooling
The PCM monitors the CHT sensor input to determine whether to initiate emergency corrective actions as a result of an engine over temperature condition. The PCM will shut down four of the eight cylinders by turning their respective fuel injectors off when the CHT sensor value exceeds 107°C (225°F), allowing the engine to cool and providing a reduced performance "limp-home/limp-to-service" mode. When this occurs the CHECK ENGINE indicator will illuminate and the fail-safe cooling warning indicator (thermometer symbol) flashes. At the same time, the engine coolant temperature gauge indicates hot (H) and an audible tone sounds every five seconds. The PCM will shut down the engine when the CHT sensor value reaches approximately 166°C (330°F). Immediately prior to engine shutdown, the CHECK ENGINE indicator will remain illuminated, the fail-safe cooling warning indicator (thermometer symbol) continues to flash, the engine coolant temperature gauge bars begin to flash and an audible tone sounds every five seconds.

CHECK AIR SUSPENSION
The CHECK AIR SUSPENSION indicator illuminates when a concern in the air suspension system is detected or when the air suspension switch is in the OFF position. During prove-out, when a concern is detected or the air suspension switch is OFF, an audible tone will sound and the CHECK AIR SUSPENSION indicator will flash on and off for five seconds. The CHECK AIR SUSPENSION indicator will then remain illuminated until the concern is corrected or the air suspension switch is switched ON.

TRUNK AJAR
The TRUNK AJAR indicator illuminates when the luggage compartment door is ajar or a concern is detected in the luggage compartment door open warning lamp circuit. During prove-out, when a concern is detected or the luggage compartment door is ajar, an audible tone will sound and the TRUNK AJAR warning indicator will flash on and off for five seconds. The TRUNK AJAR will then remain illuminated until the concern is corrected or the luggage compartment door is closed.

DOOR AJAR
The DOOR AJAR warning indicator illuminates when a front or rear door is ajar or a concern is detected in the door open warning lamp circuit. During prove-out, when a concern is detected or a door is ajar, an audible tone will sound and the DOOR AJAR warning indicator will flash on and off for five seconds. The DOOR AJAR warning indicator will then remain illuminated until the concern is corrected or the appropriate door is closed.

LOW WASHER FLUID
The LOW WASHER FLUID indicator illuminates when windshield washer fluid level is below specified levels or a concern is detected in the windshield washer fluid level circuit. During prove-out, when a concern is detected or the windshield washer fluid level is low, an audible tone will sound and the LOW WASHER FLUID indicator will flash on and off for five seconds. The LOW WASHER FLUID indicator will then remain illuminated until the concern is corrected or the windshield washer fluid level is raised above specified level.

CHECK FUEL CAP
The CHECK FUEL CAP display, located in the left message center display, is used to indicate significant leaks in the evaporative emissions system due to a loose, missing or defective fuel cap, or other fuel evaporative concern. The fuel tank pressure is monitored by the powertrain control module (PCM). If a leak is detected, the PCM signals a fault to the instrument cluster through the SCP network. Once the PCM has detected a major leak and the CHECK FUEL CAP indicator is illuminated, the CHECK FUEL CAP indicator will remain illuminated until the fuel cap has been secured and the vehicle has been operated for several minutes.