Bendix Commercial Vehicle Systems MC-30 TRAILER ABS CONTROLLER - Manual (Page 24)

24
SECTION A - POWER-UP SEQUENCE -
TRAILER MOUNTED ABS INDICATOR LAMP
ABS Indicator Lamp at Power-Up
Verify that the ABS indicator lamp stays
on for 2.5 seconds and then turns off.
The ABS indicator lamp should
immediately illuminate when power
is applied to the trailer.
Apply ignition or brake light power
and observe the ABS indicator lamp.
YES
NO
NO
YES
The MC-30 ™ controller
is functioning normally.
No service to ABS unit
is needed.
ABS indicator lamp
does not come on.
Go to Section C.
The ABS indicator lamp
stays on.
Go to Section E.
TROUBLESHOOTING
Fault information can be retrieved from the MC-30 ™ controller by using the diagnostic LED display, blink code diagnostics,
or a diagnostic tool. However, the technician must also confi rm whether the fault resides in the component, wiring or
connectors. The following troubleshooting fl ow charts will assist the technician in isolating the cause of the fault.
Troubleshooting should always begin by observing the ABS indicator lamp during the MC-30 ™ controller power-
up sequence.
If it is necessary to make electrical measurements, always begin by taking voltage and resistance measurements at the
30-pin pigtail harness connector.
Once the circuit fault is found, isolate the area needing repair by repeating the measurements at all connections in the
affected circuit towards the modulator, wheel speed sensor, etc.
No voltage or resistance measurements are to be made on the bulkhead connector pins of the EC-30T ™ controller.
When repairs are made, reconnect the electrical connector to the MC-30 ™ controller. Torque the connector retaining
jack-screw to 15-20 in. lbs. Over-tightening the ECU connector jack-screw can cause damage to the EC-30T ™
controller.
Troubleshooting Flowcharts
Section A - (Power-Up) Trailer Mounted ABS Indicator Lamp
Section B - (Power-Up) Dash Mounted ABS Indicator Lamp
Section C - Trailer Mounted ABS Indicator Lamp
Section D - Dash Mounted Trailer ABS Indicator Lamp
Section E - Diagnostic LED Quick Reference
Section F - Power to the MC-30 ™ Controller
Section G - Wheel Speed Sensors
Section H - ABS Modulators