Liberty 4WD V6-3.7L (2009)
Traction Control Indicator Lamp: Description and Operation
ESP With BAS Indicator - Operation
OPERATION
The ESP/BAS indicator gives an indication to the vehicle operator when the Electronic Stability Program (ESP)/Brake Assist System (BAS) has been
activated. 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) and the All-Wheel Drive Control Module (AWDCM) over the Controller Area
Network (CAN) data bus.
The ESP/BAS indicator Light Emitting Diode (LED) is completely controlled by the instrument cluster logic circuit, and that logic will only allow this
indicator to operate when the instrument cluster receives a battery current input on the fused ignition switch output (run-start) circuit. 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 ESP/BAS indicator for the following reasons:
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Bulb Test - Each time the ignition switch is turned to the ON position the ESP/BAS indicator is illuminated for about four seconds as a bulb test.
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ESP/BAS Indicator Lamp-On Message - Each time the cluster receives an electronic ESP/BAS indicator lamp-ON message from the CAB
indicating that the ESP/BAS system has been activated, the ESP/BAS 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.
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ESP Full Off Textual Message - Each time the cluster receives an electronic ESP Full OFF indicator lamp-ON message from the CAB
indicating that the ESP/BAS system has been manually disabled, an ESP Full OFF textual message will appear within the cluster odometer
display. The ESP Full OFF textual message remains displayed 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.
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ESP Permanent Disable Textual Message - Each time the cluster receives an electronic ESP Permanent Disable message from the CAB
indicating that the ESP/BAS system has been permanently disabled, an ESP OFF textual message will appear within the cluster odometer display
for about 10 seconds each time the ignition switch is turned to the ON position.
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Actuator Test - Each time the cluster is put through the actuator test, the ESP/BAS 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 CAB continually monitors the ESP/BAS circuits and sensors to decide whether the system is in good operating condition and the proper outputs to
the components of the system. The CAB then sends the proper lamp-ON or lamp-OFF message to the ElectroMechanical Instrument Cluster (EMIC)
(also known as the Cab Compartment Node/CCN).
For proper diagnosis of the ESP/BAS system, the CAB, the AWDCM, the EMIC, the CAN data bus or the electronic communication related to the
ESP/BAS indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.
