Sprinter 3500 V6-30L DSL Turbo | ABS Indicator Description
ABS Light: Description and Operation
ASR/ESP Warning Indicator
Description
DESCRIPTION
An Acceleration Slip Regulation (ASR) (also known as traction control)/Electronic Stability Program (ESP) warning indicator is standard equipment on
all instrument clusters. This indicator is located directly above the speedometer needle hub.
The ASR/ESP warning indicator consists of a stencil-like cutout of an ! (exclamation point) within a triangle 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 ASR/ESP warning indicator is serviced as a unit with the instrument cluster.
Operation
OPERATION
The Acceleration Slip Regulation (ASR) (also known as traction control)/Electronic Stability Program (ESP) warning indicator gives an indication to the
vehicle operator of the current status of the ASR system, the ESP system or both in providing road control and stability to the vehicle. This indicator is
controlled by a transistor on the instrument cluster circuit board based upon cluster programming and electronic messages received by the cluster over
the Controller Area Network (CAN) data bus from the Controller Antilock Brake (CAB) (also known as the Antilock Brake System/ABS or Electronic
Stability Program/ESP controller).
The ASR/ESP warning 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 detects that the ignition switch is in the ON position. Therefore, the LED will always be OFF
when the ignition switch is in any position except ON. The LED only illuminates when it is provided a path to ground by the instrument cluster
transistor. The instrument cluster will turn ON the ASR/ESP warning indicator for the following reasons:
-
Bulb Test - Each time the ignition switch is turned to the ON position the ASR/ESP warning indicator is illuminated briefly as a bulb test.
-
ASR/ESP Warning Indicator Lamp-On Message - Each time the cluster receives an electronic ASR/ESP warning indicator lamp-ON
message from the CAB, the indicator will be illuminated. This indicator can be flashed ON and OFF, or illuminated solid, as dictated by the CAB
message. The indicator is illuminated solid when the ASR system has been manually deactivated using the ASR switch. The indicator is flashed
ON and OFF when the ASR system, the ESP system, or both are actively engaged in providing the vehicle with electronic traction or stability
enhancements. The indicator remains illuminated solid or flashing 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.
The CAB continually monitors all of the ASR system and ESP system circuits and components to determine the correct operation for these systems. The
CAB then sends the proper lamp-ON or lamp-OFF messages to the ElectroMechanical Instrument Cluster (EMIC) (also known as the Cab Compartment
Node/CCN or KOMBI). See the owner's information packet in the vehicle glove box for more information on the features, use, and recommendations
concerning activation and deactivation of the ASR system.
For proper diagnosis of the ASR switch, the ASR system, the ESP system, the CAB, the EMIC, the CAN data bus or the electronic communication
related to ASR/ESP warning indicator operation, a diagnostic scan tool is required. Refer to the appropriate diagnostic information.
