Part 2 of 3
CRUISE INDICATORA cruise indicator is standard equipment on all instrument clusters, but is only functional on vehicles equipped with the optional speed control system. The cruise indicator is located near the upper edge of the instrument cluster overlay, in the upper left quadrant of the cluster. The cruise indicator consists of a stencil-like cutout of the word "CRUISE" in the opaque layer of the instrument cluster overlay. The dark outer layer of the overlay prevents the indicator from being clearly visible when the it is not illuminated. A green lens behind the cutout in the opaque layer of the overlay causes the "CRUISE" text to appear in green through the translucent outer layer of the overlay when it is illuminated from behind by a Light Emitting Diode (LED) soldered onto the instrument cluster electronic circuit board. When the exterior lighting is turned ON, the illumination intensity of the cruise indicator is one-step dimmable, which is adjusted using the panel lamps dimmer control ring on the left multi-function switch control stalk. The cruise indicator is serviced as a unit with the instrument cluster.
The cruise indicator gives an indication to the vehicle operator when the speed control system is turned ON, regardless of whether the speed control is engaged. This indicator is controlled by a transistor on the instrument cluster electronic circuit board based upon the cluster programming and electronic messages received by the cluster from the Powertrain Control Module (PCM) over the Programmable Communications Interface (PCI) data bus. The cruise indicator Light Emitting Diode (LED) receives battery current on the instrument cluster electronic circuit board through the fused ignition switch output (run-start) circuit whenever the ignition switch is in the ON or Start positions; therefore, the indicator will always be OFF when the ignition switch is in any position except ON or Start. The LED only illuminates when it is provided with a path to ground by the instrument cluster transistor.
The instrument cluster will turn on the cruise indicator for the following reasons:
* Cruise Lamp-ON Message - Each time the cluster receives a cruise lamp-ON message from the PCM indicating the speed control system has been turned ON, the cruise indicator is illuminated. The indicator remains illuminated until the cluster receives a cruise lamp-OFF message from the PCM or until the ignition switch is turned to the OFF position, whichever occurs first.
* Actuator Test - Each time the cluster is put through the actuator test, the cruise indicator will be turned ON, then OFF again during the bulb check portion of the test in order to confirm the functionality of the LED and the cluster control circuitry.
The PCM continually monitors the speed control switches to determine the proper outputs to the speed control servo. The PCM then sends the proper cruise indicator lamp-ON and lamp-OFF messages to the instrument cluster. For proper diagnosis of the speed control system, the PCM, the PCI data bus, or the message inputs to the instrument cluster that control the cruise indicator, a DRBIII scan tool is required. Refer to the appropriate diagnostic information.
FOG LAMP INDICATOR
A fog lamp indicator is standard equipment on all instrument clusters, but is only functional on vehicles equipped with the optional front and/or rear fog lamps. The fog lamp indicator is located near the upper edge of the instrument cluster overlay, in the upper left quadrant of the cluster. The fog lamp indicator consists of a stencil-like cutout of the International Control and Display Symbol icon for "Fog Lamps" in the opaque layer of the instrument cluster overlay The dark outer layer of the overlay prevents the indicator from being clearly visible when it is not illuminated. A green lens behind the cutout in the opaque layer of the overlay causes the indicator to appear in green through the translucent outer layer of the overlay when it is illuminated from behind by a Light Emitting Diode (LED) soldered onto the instrument cluster electronic circuit board. The fog lamp indicator is serviced as a unit with the instrument cluster.
The fog lamp indicator gives an indication to the vehicle operator when the optional front and/or rear fog lamps are turned ON. The availability of the front fog lamps, or rear fog lamps options varies by the market for which the vehicle is manufactured. This indicator is controlled by a hard wired input from the fog lamp switch circuitry of the left multi-function switch to the cluster. The fog lamp indicator Light Emitting Diode (LED) is grounded on the instrument cluster electronic circuit board at all times; therefore, the LED will be on anytime the front or rear fog lamps are turned on, regardless of the ignition switch position. The LED only illuminates when it is provided battery current by the fog lamp switch circuitry of the left multi-function switch.
The fog lamp switch circuitry of the left multi-function switch is connected in series between a fused B(+) fuse in the Power Distribution Center (PDC) and the front or rear fog lamp feed input to the instrument cluster through the fog lamp relay which is also in the PDC. The fog lamp switch input to the instrument cluster can be diagnosed using conventional diagnostic tools and methods.
HIGH BEAM INDICATOR
A high beam indicator is standard equipment on all instrument clusters. The high beam indicator is located near the upper edge of the instrument cluster overlay between the tachometer and the speedometer. The high beam indicator consists of a stencil-like cutout of the International Control and Display Symbol icon for "High Beam" in the opaque layer of the instrument cluster overlay. The dark outer layer of the overlay prevents the indicator from being clearly visible when it is not illuminated. A blue lens behind the cutout in the opaque layer of the overlay causes the icon to appear in blue through the translucent outer layer of the overlay when it is illuminated from behind by a replaceable incandescent bulb and bulb holder unit located on the instrument cluster electronic circuit board. The high beam indicator is serviced as a unit with the instrument cluster.
The high beam indicator gives an indication to the vehicle operator when the headlamp high beams are illuminated, or when the exterior lamps are inadvertently left ON. This indicator is controlled by a hard wired input from the headlamp beam select switch circuitry of the left multi-function switch to the cluster, and by the instrument cluster electronic circuit board based upon cluster programming and hard wired inputs from the head/park/fog lamp switch circuitry of the left multi-function switch, the driver door ajar switch, and the ignition switch. The high beam indicator bulb is grounded on the instrument cluster electronic circuit board at all times; therefore, the bulb will be illuminated anytime the headlamp high beams are turned ON, regardless of the ignition switch position. The bulb only illuminates when it is provided battery current by the beam select switch circuitry of the left multi-function switch, or by the instrument cluster electronic circuit board.
The instrument cluster will turn ON the high beam indicator for the following reasons:
* Beam Select Switch Input - Each time the cluster detects battery current on the beam select switch sense circuit (beam select switch closed = high beams selected or optical horn feature activated) the high beam indicator will be illuminated solid. This input can occur when the headlamp high beams are selected or when the optical horn feature is activated. The indicator remains illuminated until the beam select switch sense input to the cluster is an open circuit (beam select switch open = high beams not selected and optical horn feature not activated), or until the exterior lighting is turned OFF, whichever occurs first.
* Exterior Lamps-ON Optical Warning - Each time the cluster detects battery current on the headlamp switch output circuit (park or head lamp switch closed = exterior lighting is ON), ground on the driver door ajar switch sense circuit (driver door ajar switch closed = driver door is open), and the fused ignition switch output (run-start) input is an open circuit (ignition switch is in a position other than ON or Start), the high beam indicator will be flashed ON and OFF repeatedly The indicator will continue to flash until the exterior lighting is turned OFF, the driver door is closed, or the ignition switch is turned to the ON or Start positions, whichever occurs first.
* Actuator Test - Each time the cluster is put through the actuator test, the high beam indicator will be turned ON, then OFF again during the bulb check portion of the test to confirm the functionality of the bulb and the cluster control circuitry.
The headlamp beam select switch and circuitry is integral to the left multi-function switch on the steering column, and is connected in series between fused B(+) and the high beam indicator driver circuit input to the instrument cluster. The left multi-function switch inputs to the instrument cluster circuitry can be diagnosed using conventional diagnostic tools and methods.
LOW FUEL INDICATOR
A low fuel indicator is standard equipment on all instrument clusters. The low fuel indicator is located near the lower edge of the instrument cluster overlay, to the left of the odometer/trip odometer Vacuum Fluorescent Display (VFD). The low fuel indicator consists of a stencil-like cutout of the International Control and Display Symbol icon for "Fuel" in the opaque layer of the instrument cluster overlay. The dark outer layer of the overlay prevents the indicator from being clearly visible when it is not illuminated. An amber lens behind the cutout in the opaque layer of the overlay causes the icon to appear in amber through the translucent outer layer of the overlay when it is illuminated from behind by a Light Emitting Diode (LED) soldered onto the instrument cluster electronic circuit board. The low fuel indicator is serviced as a unit with the instrument cluster.
The low fuel indicator gives an indication to the vehicle operator when the level of fuel in the fuel tank becomes low. This indicator is controlled by a transistor on the instrument cluster electronic circuit board based upon cluster programming and electronic messages received by the cluster from the Powertrain Control Module (PCM) over the Programmable Communications Interface (PCI) data bus. The low fuel indicator Light Emitting Diode (LED) receives battery current on the instrument cluster electronic circuit board through the fused ignition switch output (run-start) circuit whenever the ignition switch is in the ON or Start positions; therefore, the LED will always be OFF when the ignition switch is in any position except ON or Start. The LED only illuminates when it is provided a path to ground by the instrument cluster transistor.
The instrument cluster will turn ON the low fuel indicator for the following reasons:
* Bulb Test - Each time the ignition switch is turned to the ON position the low fuel indicator is illuminated for about two seconds as a bulb test.
* Less Than 12.5 Percent Tank Full Message - Each time the cluster receives a message from the PCM indicating that the percent tank full is less than 12.5 (one-eighth), the low fuel indicator is illuminated and a single chime tone is sounded. The low fuel indicator remains illuminated until the cluster receives messages from the PCM for a continuous twenty seconds indicating that the percent tank full has increased by more than 0.625 gallons or until the ignition switch is turned to the OFF position, whichever occurs first. This strategy is intended to reduce the effect that fuel sloshing within the fuel tank can have on reliable indications. The chime tone feature will occur only once per ignition cycle.
* Less Than Empty Percent Tank Full Message - Each time the cluster receives a message from the PCM indicating the percent tank full is less than empty the low fuel indicator is illuminated immediately. This message would indicate that the fuel tank sender input to the PCM is a short circuit.
* More Than Full Percent Tank Full Message - Each time the cluster receives a message from the PCM indicating the percent tank full is more than full, the low fuel indicator is illuminated immediately. This message would indicate that the fuel tank sender input to the PCM is an open circuit.
* Actuator Test - Each time the cluster is put through the actuator test, the low fuel indicator will be turned ON, then OFF again during the bulb check portion of the test to confirm the functionality of the LED and the cluster control circuitry
The PCM continually monitors the fuel tank sending unit, then sends the proper messages to the instrument cluster. For further diagnosis of the low fuel indicator lamp or the instrument cluster circuitry that controls the LED, For proper diagnosis of the fuel tank sending unit, the PCM, the PCI data bus, or the message inputs to the instrument cluster that control the low fuel indicator, a DRBIII scan tool is required Refer to the appropriate diagnostic information
MALFUNCTION INDICATOR LAMP
A Malfunction Indicator Lamp (MIL) is standard equipment on all instrument clusters. The MIL is located near the lower edge of the instrument cluster overlay, to the right of the odometer/trip odometer Vacuum-Fluorescent Display (VFD). The MIL consists of a stencil-like cutout of the International Control and Display Symbol icon for "Engine" in the opaque layer of the instrument cluster overlay. The dark outer layer of the overlay prevents the indicator from being clearly visible when it is not illuminated. An amber lens behind the cutout in the opaque layer of the overlay causes the icon to appear in amber through the translucent outer layer of the overlay when it is illuminated from behind by a Light Emitting Diode (LED) soldered onto the instrument cluster electronic circuit board. The MIL is serviced as a unit with the instrument cluster.
The Malfunction Indicator Lamp (MIL) gives an indication to the vehicle operator when the Powertrain Control Module (PCM) has recorded a Diagnostic Trouble Code (DTC) for an On-Board Diagnostics II (OBDII) emissions-related circuit or component malfunction. The MIL is controlled by a transistor on the instrument cluster electronic circuit board based upon cluster programming and electronic messages received by the cluster from the PCM over the Programmable Communications Interface (PCI) data bus. The MIL Light Emitting Diode (LED) receives battery current on the instrument cluster electronic circuit board through the fused ignition switch output (run-start) circuit whenever the ignition switch is in the ON or Start positions; therefore, the LED will always be OFF when the ignition switch is in any position except ON or Start. The LED only illuminates when it is provided a path to ground by the instrument cluster transistor.
The instrument cluster will turn on the MIL for the following reasons:
* Bulb Test - Each time the ignition switch is turned to the ON position the indicator is illuminated for about seven seconds as a bulb test.
* PCM Lamp-ON Message - Each time the cluster receives a lamp-ON message from the PCM, the indicator will be illuminated. The indicator can be flashed ON and OFF, or illuminated solid, as dictated by the PCM message. For some DTC's, if a problem does not recur, the PCM will send a lamp-OFF message automatically Other DTC's may require that a fault be repaired and the PCM be reset before a lamp-OFF message will be sent. For more information on the PCM and the DTC set and reset parameters.
* Communication Error - If the cluster receives no lamp-ON or lamp-OFF message from the PCM for twenty seconds, the MIL is illuminated by the instrument cluster and a "no BUS" message will appear in the odometer/trip odometer Vacuum Fluorescent Display (VFD) to indicate a loss of bus communication. The indicator remains controlled and illuminated by the cluster until a valid lamp-ON or lamp-OFF message is received from the PCM.
* Actuator Test - Each time the cluster is put through the actuator test, the MIL will be turned ON, then OFF again during the bulb check portion of the test to confirm the functionality of the LED and the cluster control circuitry.
The PCM continually monitors the fuel and emissions system circuits and sensors to decide whether the system is in good operating condition. The PCM then sends the proper lamp-ON or lamp-OFF messages to the instrument cluster. If the instrument cluster turns on the MIL after the bulb test, it may indicate that a malfunction has occurred and that the fuel and emissions system may require service. For proper diagnosis of the fuel and emissions systems, the PCM, the PCI data bus, or the message inputs to the instrument cluster that control the MIL, a DRBIII scan tool is required. Refer to the appropriate diagnostic information.