27
SECTION D - TROUBLESHOOTING THE DASH MOUNTED TRAILER
ABS INDICATOR LAMP WITH EC-30
™
CONTROLLER
The dash mounted trailer ABS
indicator lamp did not illuminate at
vehicle power-up.
With ignition off, remove the 30-pin
connector from EC-30
™
controller.
YES
NO
Turn ignition on and measure voltage
between pin E2 and ground (pins A1,
A2 or A3).
Verify a measurement
equal to battery voltage. (About 12.0
VDC)
Only towing vehicles built after
March 1, 2001 will be required
to have a trailer ABS indicator
lamp.
The trailer ABS indicator
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. Refer to the part number and
confi guration to ensure that the
EC-30
™
controller supports PLC
communications.
Check for corrosion or damage on
the 30-pin connector and wiring. If
none is found, replace the EC-30
™
controller.
With a volt/ohm meter, check wiring,
trailer ABS indicator lamp and fuse.
When repair is made, reconnect
the 30-pin connector to the EC-30
™
controller and rerun the power up
sequence.
Go to Section A.
1
2
3
K J H G F E D C B A
EC-30
™
Controller
30-Pin Connector
E2
Trailer
ABS
Indicator
Lamp
A1,A2,A3
Ground
See note
this page
Note: If there is no wire in pin
E2 of the 30-pin connector, the
EC-30
™
controller is commanding
the trailer ABS indicator lamp,
using the J1939 or J1587 serial
communications link.
In this confi guration, the actual trailer
ABS indicator lamp is driven by
a vehicle dash controller. Obtain
the vehicle manual and verify the
wiring and function of the trailer ABS
indicator lamp.
To verify proper EC-30
™
controller
communication, refer to the EC-30
™
ABS / ATC Controller service data
sheet, SD-13-4815.
Trailer ABS indicator lamp stays on
with no trailer connected to towing
vehicle.
With a volt/ohm meter, verify no
continuity from trailer ABS indicator
lamp connector pin to ground.
Check for corrosion or damage on
the 30-pin connector and wiring. If
no issues are found, replace the
EC-30
™
controller.
With ignition off, remove the 30-pin
connector from EC-30
™
controller.
See note
this page
