User Guide

8
AUTO CALIBRATION
For optional ATC performance the ECU utilizes a feature
referred to as auto calibration. Auto calibration allows the
ECU to compensate for various tire sizes throughout the life
of the vehicle. As there are many conditions that can result
in the appearance of a change in the tire size, several items
must be satisfied before the auto calibration feature is active.
The auto calibration feature would automatically change the
ECUs imbedded tire sizes if the difference exceeded
approximately 8%. If issues occur with your ATC due to tire
size changes please contact 1-800-AIR-BRAKE or
1-800-247-2725 for assistance.
SINGLE FAILURE
The following list and chart describes how the antilock and
traction systems respond to a specific component failure.
(Note: right and left; front, mid and rear are determined from
the driver's seat. Left front is therefore the corner closest to
the driver.)
For example, if the right mid sensor ("RM Sensor" on the
chart) fails, front and rear antilock will still be operative.
Traction will be disabled. On those axles where antilock is
disabled the system reverts to standard air braking.
Front modulator - If a front modulator fails, antilock on that
wheel is disabled. Antilock and traction on all other wheels
remains active.
Rear modulator - A rear modulator failure disables the traction
system. Antilock on that wheel will also be disabled, but
antilock on all other wheels remains active.
Front sensor - The wheel is still modulated using input from
the opposite sensor on the front axle. The traction system
is disabled.
Mid or rear sensor - In a four sensor system, antilock on
that wheel(s) is disabled, but antilock on all other wheels
remains active. In a six sensor system, antilock remains
active using input from the remaining functional sensor. In
both the four and six sensor system traction control is
disabled.
Controller - Antilock and traction are disabled. The system
reverts to standard air braking.
Traction solenoid - Traction control is disabled. Antilock
remains active.
Engine Control Module - If the engine control module (ECM)
or the wiring from the EC-17
™
controller to the ECM fails,
traction control is disabled. Antilock remains active.
Voltage - If system voltage is out of range, antilock and
traction are disabled. The system reverts to standard air
braking.
MULTIPLE FAILURES
In the event that multiple failures occur, the dash lamp will
react as it normally would during a single failure, and the
EC-17
™
controller equipped with LEDs will show one
diagnostic trouble code at a time. When the first diagnostic
trouble code is fixed and the system is reset, the next
diagnostic trouble code area will appear at the LEDs. This
way, the driver or mechanic does not lose track of diagnostic
trouble code areas, and the system is not restored until
each and every error is corrected and the EC-17
™
controller
is cleared of all diagnostic trouble codes.
DIAGNOSTIC TROUBLE CODE LOCATION
SYSTEM STILL OPERATING (YES/NO)
Failed ABS Front ABS Rear Traction Std.
Device
Left Right Left Right Braking
RF Sensor YES YES YES YES NO YES
LF Sensor YES YES YES YES NO YES
RM Sensor YES YES YES YES NO YES
LM Sensor YES YES YES YES NO YES
RR Sensor YES YES YES NO
1
NO YES
LR Sensor YES YES NO
1
YES NO YES
RF Modulator YES NO YES YES YES YES
LF Modulator NO YES YES YES YES YES
RR Modulator YES YES YES NO NO YES
LR Modulator YES YES NO YES NO YES
Controller NO NO NO NO NO YES
Tract. SolenoidYES YES YES YES N0 YES
Engine Control
Module
2
YES YES YES YES NO YES
Voltage
2
NO NO NO NO NO YES
1
ABS is still available in 6 sensors system if mid sensor is functional
2
When ECM wiring or voltage "corrects" itself, system is restored.
FRONT OF VEHICLE
REAR OF VEHICLE
DRIVER
RIGHT FRONT
LEFT FRONT
RIGHT REAR
LEFT REAR
RIGHT MID
LEFT MID
RESET
SWITCH
FIGURE 7 - EC-17
™
CONTROLLER LED DIAGNOSTIC
DISPLAY
FRT MID RER RHT LFT TRC MOD SEN ECU VLT
FRONT MIDDLE REAR RIGHT LEFT TRACTION MODULATOR SENSOR ECU VOLTAGE