Bendix Commercial Vehicle Systems EC-30 ABS/ATC CONTROLLER 2/08 User Manual
Page 21

21
SECTION B - EC-30
™
CONTROLLER POWER-UP SEQUENCE -
TRAILER ABS WARNING LAMP
Trailer ABS Warning Lamp at
Power-Up
Verify that a PLC trailer is connected to 
the tractor via the seven pin connector. 
Turn ignition on and observe the trailer 
ABS warning lamp. 
The trailer ABS warning lamp should 
illuminate within 2 seconds of ignition 
power being applied to the vehicle.
YES
NO
The trailer ABS warning lamp stays on. 
This is an indication that the trailer ABS 
unit has a fault. Identify the manufacturer 
of the trailer ABS unit and follow 
recommended steps for diagnosis and 
repair. For Bendix
®
MC-30
™
trailer ABS
controller assembly, see SD-13-4834.
If the trailer ABS lamp stays on with no 
trailer connected, go to Section E.
Trailer ABS warning lamp does not come 
on.
Note: Only towing vehicles built after 
March 1, 2001 will be required to have 
a trailer ABS warning lamp. The trailer 
ABS warning lamp, located on the vehicle 
dash, is only activated by a PLC signal 
from a trailer or diagnostic tool. The 
towing vehicle must be equipped with 
an EC-30
™
controller with PLC. Verify
correct EC-30
™
controller part number.
Verify that a PLC signal is present on the 
EC-30
™
controller power lines. (Refer to
the EC-30
™
controller with PLC section of
this document.) If a PLC signal is present 
and the trailer ABS lamp does not come 
on at power-up,
go to Section E.
Verify that the trailer ABS warning 
lamp stays on for 2.5 seconds and 
then turns off.
NO
YES
T h e A B S u n i t i s 
functioning normally. 
No service to ABS 
components is needed.
