Commander 2WD V8-4.7L (2008)
Traction Control Indicator Lamp: Description and Operation
Traction Control Indicator
Description
DESCRIPTION
A traction control indicator is standard equipment on all instrument clusters. However, on vehicles not equipped with the optional Electronic Stability
Program (ESP)/Brake Assist System (BAS)/Traction Control System (TCS) this indicator is electronically disabled. This indicator is located above the
coolant temperature gauge and to the right of the tachometer in the cluster overlay. Illumination of this indicator may also be accompanied by the display
of certain textual messages in the cluster reconfigurable dot matrix display.
The traction control indicator consists of a stencil-like cutout of the International Control and Display Symbol icon for Stability - Anti-Spin 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 Light Emitting Diode (LED) behind the cutout in the opaque layer of the overlay causes the indicator to appear in amber through
the translucent outer layer of the overlay when it is illuminated from behind by the LED, which is soldered onto the instrument cluster electronic circuit
board.
The traction control indicator is serviced as a unit with the instrument cluster.
Operation
OPERATION
The traction control indicator gives an indication to the vehicle operator when the Electronic Stability Program (ESP)/Brake Assist System
(BAS)/Traction Control System (TCS) has been activated. This indicator is controlled by the instrument cluster logic circuit based upon cluster
programming and electronic messages received by the cluster from the Controller Antilock Brake (CAB) over the Controller Area Network (CAN) data
bus.
The traction control indicator 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 indicator will always be OFF
when the ignition switch is in any position except ON or START. The indicator only illuminates when it is provided a path to ground by the instrument
cluster circuitry. The instrument cluster will turn ON the traction control indicator for the following reasons:
-
Bulb Test - Each time the ignition switch is turned to the ON position the traction control indicator is illuminated for about four seconds as a bulb
test. The entire bulb test is a function of the CAB.
-
Traction Control Indicator Lamp-On Message - Each time the cluster receives an electronic traction control indicator lamp-ON message
from the CAB indicating that the ESP/BAS/TCS has been activated, the traction control indicator will be illuminated. The indicator can be flashed
ON and OFF, or illuminated solid, as dictated by the CAB message. The indicator remains illuminated solid or continues to flash 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 cluster is put through the actuator test, the traction control 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.
