Instrument Cluster
The Hybrid Electronic Instrument Cluster (HEC) gauges, warning indicators, and message center displays are either controlled and driven directly hardwired or the information is requested and received through the Standard Corporate Protocol (SCP). The REC has self-test diagnostics capabilities using scan tool.
Hybrid Electronic Instrument Cluster (HEC) Gauges
The hybrid electronic instrument cluster (HEC) houses three gauges:
- Speedometer gauge.
- Fuel gauge.
- Engine coolant temperature gauge.
Speedometer Gauge
The HEC receives the vehicle speed signal from the Anti-lock Brake System (ABS) module over the SCP and displays it on the speedometer gauge. When the REC has no vehicle speed signal, the speedometer defaults to 0.0 km/h (0.0 mph).
Fuel Gauge
The HEC receives the fuel level information directly from the fuel sending unit. When the fuel level is low, the resistance is low. When the fuel level is high, the resistance is high.
Engine Coolant Temperature Gauge
Engine coolant temperature information is received by the HEC from the powertrain control module (PCM) over the SCP. Temperatures over 123°C (253°F) will cause the engine coolant temperature gauge to display hot (H). If the engine coolant temperature data is missing or invalid, the HEC will move the engine coolant temperature gauge to the cold (C) position.
Message Center Displays
The HEC has two digital message center displays. The message center displays will fully illuminate their segments for several seconds when the ignition switch is first turned on. This is simply a bezel prove out of the message center display.
The right-side message center display indicates:
- Fuel computer/trip odometer information (e.g. FUEL ECON AVG, FUEL REMAIN, 1)1ST TO EMPTY, AVG SPEED, TRIP A B, and E/M (English/metric)). Refer to Instrument Panel,Gauges and Warning Indicators for further details about the fuel computer/trip odometer information message display.
- Low WASHER level fluid. WASHER is displayed if the windshield washer fluid level is low, causing the switch to ground the circuit.
The left-side message center display indicates:
- AIR SUSPENSION
- CIRCLE SLOWLY
- Compass
- DOORAJAR
- Odometer
- TRAC OFF
- TRAC ACTIVE
- TRUNK AJAR
- 0/DOFF
- SPEED CONTROL
Refer to Instrument Panel,Gauges and Warning Indicators, Driver Information/Message Center for more information about the message centers.
Refer to Compass for further details of the compass.
The display panel control switch is located directly above the Electronic Automatic Temperature Control (EATC) and has a SELECT and RESET button.
Odometer
The HEC receives odometer rolling count status from the Anti-lock Brake System (ABS) module and stores the mileage in Non-volatile Memory (NVM). Dashes are displayed in the odometer display and the ABS warning indicator is illuminated if the HEC fails to receive the odometer rolling count status.
Traction Control
The left-side message center displays TRAC ACTIVE and TRAC OFF. The TRAC OFF display is controlled by the REC depending on the brake system configuration it receives from the ABS or ABS/traction control (ABS/TC). The TRAC ACTIVE display illuminates if the traction control is active. The HEC will receive a traction control active telltale command message over the SCP from the ABS/TC. If the message is not received after the segment display prove-out, the HEC turns off the TRAC ACTIVE display.
0/D Off
The overdrive off (O/D OFF) display is illuminated depending on the overdrive telltale command the HEC receives from the PCM over the SCP. If the O/D switch is depressed, turning the overdrive off, the O/D OFF should be illuminated.
Speed Control
The SPEED CONTROL display illuminates when the HEC receives an ON vehicle speed control high resolution set speed command from the speed control servo. The speed control servo receives its input directly from the speed control switch. If the HEC fails to receive a vehicle speed high resolution set speed command, the HEC defaults to the last known value. After each ignition cycle, if no command is received, the HEC shall default and does not illuminate the SPEED CONTROL display.
Air Suspension
The AIR SUSPENSION display illuminates depending on the suspension system state status message the HEC receives from the air suspension control module over the SCP. If the HEC fails to receive a suspension system state status after the three-second prove out duration, the HEC continues to illuminate the AIR SUSPENSION display. The HEC will only turn off the AIR SUSPENSION display if it receives a suspension system state status message with no failure indicated.
Warning Indicators
Low Oil Pressure Indicator
The low oil pressure indicator on the HEC receives the oil pressure status directly from the oil pressure switch. With the ignition switch in the ON position, the low oil pressure indicator should be illuminated. After the engine is started and the oil pressure builds up, the oil pressure switch closes and turns off the low oil pressure indicator.
Brake System Warning Indicator
The brake system indicator proves out when the ignition switch is in the START position, grounding the circuit. The indicator illuminates if the brake fluid level is low or if the parking brake pedal is depressed.
Safety Belt Indicator
The HEC safety belt indicator indicates if the driver safety belt is fastened when the ignition switch is turned ON. The HEC receives the safety belt status from the Lighting Control Module (LCM). The safety belt indicator will turn off after 60 seconds from when the engine was started, regardless of the driver safety belt status. An audible safety belt chime is provided by the LCM if the HEC detects the driver safety belt to be unfastened.
Fail-Safe Cooling Mode Indicator
The HEC performs a three-second prove out of the fail-safe cooling indicator when the ignition switch is turned on. After the engine is started, the PCM sends the HEC a fail-safe cooling mode status. If the HEC does not receive a message from the PCM, the HEC assumes the OFF status and turns off the indicator.
Service Engine Soon
The SERVICE ENGINE SOON indicator is turned on with the ignition switch in the ON position. After the engine is started, the SERVICE ENGINE SOON indicator remains on for a prove out duration of three seconds. If the PCM fails to send the REC an OFF status message, the SERVICE ENGINE SOON indicator will remain illuminated. After the prove out duration, the SERVICE ENGINE SOON indicator is controlled directly by the PCM via the SCP to the HEC.
Check Trac Indicator
On vehicles equipped with ABS/TC, the HEC proves out the CHECK TRAC indicator. If, during the three-second prove out, the traction control system message is received with a fault state status, the CHECK TRAC indicator remains illuminated. The CHECK TRAC indicator also remains illuminated if the HEC receives no status message from the ABS/TC.
High Beam Indicator
The high beam indicator is controlled by the Lighting Control Module (LCM) over the SCP. When the headlamps are turned on, the LCM sends the HEC a high beam indicator telltale command ON message. The HEC does not prove out the high beam indicator. If the HEC does not receive a high beam indicator telltale command from the LCM, the HEC does not illuminate the high beam indicator.
Air Bag Indicator
The air bag indicator is controlled by the air bag module. Refer to Air Bag Systems for further description and operation.
Charging System Indicator
The charging system indicator is directly controlled by the generator. If low voltage is detected, the charging system indicator turns on.
ABS Indicator
The ABS indicator has multiple functions. The REC proves out the ABS indicator when the ignition switch is turned ON. After the engine is started, the HEC monitors the SCP messages for odometer rolling count status from the ABS module. If at any time the HEC does not receive this message every two seconds, the HEC illuminates the ABS indicator.
Left and Right Turn Signal Indicators
The left and right turn signal indicators on the HEC are controlled by the multi-function switch and also operate together when the hazard lamps are turned on.
Instrument Cluster Replacement
When an instrument cluster replacement is necessary, contact the Cluster Order System at 1-800-259-9700 (U.S.) or 1-800-663-9974 (Canada). The Passive Anti-theft System (PATS) must be reconfigured after replacement of the HEC. Refer to the PATS Configuration Command Index in Antitheft and Alarm Systems. For additional reprogramming assistance, refer to the Help Screen on the scan tool configuration card. PATS Configuration Command Index