Part 1 of 3
IndicatorsIndicators are located in various positions within the EMIC and are all connected to the EMIC circuit board. The high beam indicator, washer fluid indicator, security indicator, and turn signal indicators are hard wired. The brake indicator is controlled by CCD data bus messages from the Controller Anti-Lock Brake (CAB) and the hard wired park brake switch input to the EMIC. The seatbelt indicator is controlled by the EMIC programming, CCD data bus messages from the Airbag Control Module (ACM), and the hard wired seat belt switch input to the EMIC. The Malfunction Indicator Lamp (MIL) is normally controlled by CCD data bus messages from the Powertrain Control Module (PCM); however, if the EMIC loses CCD data bus communications, the EMIC circuitry will automatically turn the MIL ON, and flash the odometer VFD ON and OFF repeatedly until CCD data bus communication is restored. The EMIC uses CCD data bus messages from the CTM, the PCM, the ACM, and the CAB to control all of the remaining indicators. Different indicators are controlled by different strategies; some receive fused ignition switch output from the EMIC circuitry and have a switched ground, while others are grounded through the EMIC circuitry and have a switched battery feed.
In addition, certain indicators in this instrument cluster are configurable. This feature allows the configurable indicators to be automatically enabled or disabled by the EMIC circuitry for compatibility with certain optional equipment. The cruise indicator, overdrive-off indicator, and the transmission over- temp indicator are automatically configured, either electronically or mechanically If the EMIC is disconnected from the fused B(+) circuit for more than about five minutes the EMIC will forget its previous electronic configuration settings, but will learn the proper indicator configuration settings again when it is reinstalled in a vehicle.
The hard wired indicators are diagnosed using conventional diagnostic methods. The EMIC and CCD bus message controlled indicators are diagnosed using the EMIC self-diagnostic actuator test. Proper testing of the CCD data bus and the data bus message inputs to the EMIC that control each indicator require the use of a DRB III scan tool. Refer to the appropriate diagnostic information. Specific operation details for each indicator may be found elsewhere in this service information.
ABS INDICATOR
An Antilock Brake System (ABS) indicator is standard equipment on all instrument clusters. This indicator serves the standard equipment 4-Wheel Anti- Lock (4WAL) brake system. The ABS indicator is located near the lower edge of the instrument cluster overlay, to the right of center. The ABS indicator consists of a stencilled cutout of the International Control and Display Symbol icon for "Failure of Anti-lock Braking System" 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 ABS indicator is serviced as a unit with the instrument cluster.
The ABS indicator gives an indication to the vehicle operator when the ABS system is faulty or inoperative. This indicator is controlled by a transistor on the instrument cluster circuit board based upon cluster programming and electronic messages received by the cluster from the Controller Antilock Brake (CAB) over the Chrysler Collision Detection (CCD) data bus. The ABS 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 ABS indicator for the following reasons:
* Bulb Test - Each time the ignition switch is turned to the ON position the ABS indicator is illuminated by the cluster for about two seconds as a bulb test.
* ABS Lamp-On Message - Each time the cluster receives a lamp-on message from the CAB, the ABS indicator will be illuminated. The indicator remains illuminated until the cluster receives a lamp-OFF message from the CAB, or until the ignition switch is turned to the OFF position, whichever occurs first.
* Communication Error - If the cluster receives no lamp-on or lamp-OFF messages from the CAB for six consecutive seconds, the ABS indicator is illuminated. The indicator remains illuminated until the cluster receives a valid message from the CAB, or until the ignition switch is turned to the OFF position, whichever occurs first.
* Actuator Test - Each time the instrument cluster is put through the actuator test, the ABS 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.
* ABS Diagnostic Test - The ABS indicator is blinked ON and OFF by lamp-on and lamp-off messages from the CAB during the performance of the ABS diagnostic tests.
The CAB continually monitors the ABS circuits and sensors to decide whether the system is in good operating condition. The CAB then sends the proper lamp-on or lamp-off messages to the instrument cluster. If the CAB sends a lamp-on message after the bulb test, it indicates that the CAB has detected a system malfunction and/or that the ABS system has become inoperative. The CAB will store a Diagnostic Trouble Code (DTC) for any malfunction it detects. Each time the ABS indicator fails to light due to an open or short in the cluster ABS indicator circuit, the cluster sends a message notifying the CAB of the condition, and the CAB will store a DTC. For proper diagnosis of the antilock brake system, the CAB, the CCD data bus, or the message inputs to the instrument cluster that control the ABS indicator, a DRB III scan tool is required. Refer to the appropriate diagnostic information.
AIRBAG INDICATOR
An airbag indicator is standard equipment on all instrument clusters. However, on vehicles not equipped with airbags, this indicator is electronically disabled. The airbag indicator is located near the lower edge of the instrument cluster overlay, to the right of center. The airbag indicator consists of a stencil-like cutout of the words "AIR BAG" 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 red lens behind the cutout in the opaque layer of the overlay causes the "AIR BAG" text to appear in red 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 airbag indicator is serviced as a unit with the instrument cluster.
The airbag indicator gives an indication to the vehicle operator when the airbag system is faulty or inoperative. The airbag indicator is controlled by a transistor on the instrument cluster circuit board based upon cluster programming and electronic messages received by the cluster from the Airbag Control Module (ACM) over the Chrysler Collision Detection (CCD) data bus. The airbag 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 a path to ground by the instrument cluster transistor.
The instrument cluster will turn ON the airbag indicator for the following reasons:
* Bulb Test - Each time the ignition switch is turned to the ON position the airbag indicator is illuminated for about seven seconds. The first two seconds is the cluster bulb test function, and the remainder is the ACM bulb test function.
* ACM Lamp-On Message - Each time the cluster receives a lamp-on message from the ACM, the airbag indicator will be illuminated. The indicator remains illuminated for about twelve seconds or until the cluster receives a lamp-off message from the ACM, whichever is longer.
* Communication Error - If the cluster receives no airbag messages for three consecutive seconds, the airbag indicator is illuminated. The indicator remains illuminated for about twelve seconds or until the cluster receives a single lamp-off message from the ACM, whichever is longer.
* Actuator Test - Each time the cluster is put through the actuator test, the airbag 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 ACM continually monitors the airbag system circuits and sensors to decide whether the system is in good operating condition. The ACM then sends the proper lamp-on or lamp-off messages to the instrument cluster. If the ACM sends a lamp-on message after the bulb test, it indicates that the ACM has detected a system malfunction and/or that the air- bags may not deploy when required, or may deploy when not required. The ACM will store a Diagnostic Trouble Code (DTC) for any malfunction it detects. Each time the airbag indicator fails to illuminate due to an open or short in the cluster airbag indicator circuit, the cluster sends a message notifying the ACM of the condition. The ACM will store a DTC and the cluster will begin blinking the seat belt indicator.For proper diagnosis of the airbag system, the ACM, the CCD data bus, or the message inputs to the instrument cluster that control the airbag indicator, a DRB III scan tool is required. Refer to the appropriate diagnostic information.
BRAKE/PARK BRAKE INDICATOR
A brake indicator is standard equipment on all instrument clusters. The brake indicator is located near the lower edge of the instrument cluster overlay, to the left of center. The brake indicator consists of a stencil-like cutout of the word "BRAKE" 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 red lens behind the cutout in the opaque layer of the overlay causes the "BRAKE" text to appear in red through the translucent outer layer of the overlay when the indicator is illuminated from behind by a Light Emitting Diode (LED) soldered onto the instrument cluster electronic circuit board. The brake indicator is serviced as a unit with the instrument cluster.
The brake indicator gives an indication to the vehicle operator when the parking brake is applied, or when there are certain brake hydraulic system malfunctions. This indicator is controlled by a transistor on the instrument cluster circuit board based upon cluster programming, and electronic messages received by the cluster from the Controller Antilock Brake (CAB) over the Chrysler Collision Detection (CCD) data bus. The brake 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 brake indicator for the following reasons:
* Bulb Test - Each time the ignition switch is turned to the ON position the brake indicator is illuminated by the instrument cluster for about four seconds as a bulb test.
* Brake Lamp-ON Message - Each time the cluster receives a lamp-ON message from the CAB, the brake indicator will be illuminated. The indicator remains illuminated until the cluster receives lamp- off messages from the CAB, or until the ignition switch is turned to the OFF position, whichever occurs first.
* Park Brake Switch Status - Each time the cluster receives a hard wired input from the park brake switch indicating that the park brake is applied or not fully released, the brake indicator will be illuminated. The indicator remains illuminated until the park brake switch input indicates that the park brake is released, or until the ignition switch is turned to the OFF position, whichever occurs first.
* Actuator Test - Each time the instrument cluster is put through the actuator test, the brake 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 park brake switch on the park brake pedal mechanism provides a hard wired ground input to the instrument cluster circuitry through the park brake switch sense circuit whenever the park brake is applied or not fully released. The brake warning indicator switch on the brake combination valve provides a hard wired ground input to the CAB circuitry through the brake warning indicator driver circuit whenever the pressures in the two halves of the split brake hydraulic system are unequal. The CAB then sends the proper lamp-ON or lamp-OFF messages to the instrument cluster. If the CAB sends a lamp-ON message after the bulb test, it indicates that the CAB has detected a brake hydraulic system malfunction and/or that the ABS system has become inoperative. The CAB will store a Diagnostic Trouble Code (DTC) for any malfunction it detects. The park brake switch input to the instrument cluster and the brake pressure switch input to the CAB can be diagnosed using conventional diagnostic tools and methods. For proper diagnosis of the antilock brake system, the CAB, the CCD data bus, or the message inputs to the instrument cluster that control the brake indicator, a DRB III scan tool is required. Refer to the appropriate diagnostic information.