Part 2 of 5

ABS INDICATOR
An Antilock Brake System (ABS) indicator is standard equipment on all instrument clusters. This indicator serves both the standard equipment Rear Wheel Anti-Lock (RWAL) and optional equipment 4-Wheel Anti-Lock (4WAL) brake systems. The ABS indicator is located near the lower edge of the instrument cluster overlay, to the left 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 (ST/RUN) 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 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 stenciled cutout of the word "AIRBAG" 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 "AIRBAG" 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 (ST/RUN) 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 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 airbags 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 begins blinking the seat belt indicator. (Refer to SEATBELT INDICATOR - OPERATION). 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 right of center. The brake indicator consists of a stenciled 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 it 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 a hard wired input to the instrument cluster, 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 (ST/RUN) 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.
- Park Brake-On - If the park brake is applied or not fully released with the ignition switch in the ON position, the brake indicator is illuminated solid. The brake indicator will blink ON and OFF repeatedly when the park brake is applied or not fully released and the ignition switch is in the ON position if a vehicle with an automatic transmission is not in Park or Neutral, or if the engine is running on vehicles with a manual transmission.
- 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 a lamp-OFF 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 brake indicator will be turned ON 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 CAB continually monitors the brake pressure switch on the brake combination valve to determine if 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 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.

CHECK GAUGES INDICATOR
A check gauges indicator is standard equipment on all instrument clusters. The check gauges indicator is located on the lower edge of the instrument cluster overlay, to the right of center. The check gauges indicator consists of a stenciled cutout of the words "CHECK GAGES" 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 red lens behind the cutout in the opaque layer of the overlay causes the "CHECK GAGES" 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 check gauges indicator is serviced as a unit with the instrument cluster.

The check gauges indicator gives an indication to the vehicle operator when certain instrument cluster gauge readings reflect a condition requiring immediate attention. This indicator is controlled by a transistor on the instrument cluster circuit board based upon the cluster programming and electronic messages received by the cluster from the Powertrain Control Module (PCM) over the Chrysler Collision Detection (CCD) data bus. The check gauges indicator Light Emitting Diode (LED) receives battery current on the instrument cluster electronic circuit board through the fused ignition switch output (ST/RUN) 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 check gauges indicator for the following reasons:
- Bulb Test - Each time the ignition switch is turned to the ON position the check gauges indicator is illuminated for about two seconds as a bulb test.
- Engine Temperature High Message - Each time the cluster receives a message from the PCM indicating the engine coolant temperature of a gasoline engine is about 122 °C (253 °F) or higher, or a diesel engine is about 112 °C (233 °F) or higher, the check gauges indicator will be illuminated. The indicator remains illuminated until the cluster receives a message from the PCM indicating that the temperature of a gasoline engine is about 119 °C (246 °F) or lower, a diesel engine is about 109 °C (226 °F) or lower, or until the ignition switch is turned to the OFF position, whichever occurs first.
- Engine Oil Pressure Low Message - Each time the cluster receives a message from the PCM indicating the engine oil pressure of a gasoline engine is about 3.45 kPa (0.5 psi) or lower, or a diesel engine is about 51.71 kPa (7.5 psi) or lower, the check gauges indicator will be illuminated. The indicator remains illuminated until the cluster receives a message from the PCM indicating that the engine oil pressure of a gasoline engine is above 3.45 kPa (0.5 psi), a diesel engine is above 51.71 kPa (7.5 psi), or until the ignition switch is turned to the OFF position, whichever occurs first. The cluster will only turn the indicator on in response to an engine oil pressure low message if the engine speed is greater than zero.
- System Voltage Low Message - Each time the cluster receives a message from the PCM indicating the electrical system voltage is less than 11.5 volts, the check gauges indicator will be illuminated. The indicator remains illuminated until the cluster receives a message from the PCM indicating the electrical system voltage is greater than 12.0 volts (but less than 16.6 volts), or until the ignition switch is turned to the OFF position, whichever occurs first.
- System Voltage High Message - Each time the cluster receives a message from the PCM indicating the electrical system voltage is greater than 16.6 volts, the check gauges indicator will be illuminated. The indicator remains illuminated until the cluster receives a message from the PCM indicating the electrical system voltage is less than 16.1 volts (but greater than 11.5 volts), 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 indicator will be turned ON 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 engine temperature, oil pressure, and electrical system voltage, then sends the proper messages to the instrument cluster. For further diagnosis of the check gauges indicator or the instrument cluster circuitry that controls the LED, (Refer to ELECTRICAL/INSTRUMENT CLUSTER - DIAGNOSIS AND TESTING). For proper diagnosis of the PCM, the CCD data bus, or the message inputs to the instrument cluster that control the check gauges indicator, a DRB III scan tool is required. Refer to the appropriate diagnostic information.