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"RIGHT" LED

This red LED illuminates and latches on in order to indicate
the location of a problem component or its wiring.  It will
light in conjunction with either the FRONT or REAR LED
and SENS LED. This LED should not light when a MOD
LED is on.

"LEFT" LED

This red LED illuminates and latches on in order to indicate
the location of a problem component or its wiring.  It will
light in conjunction with either the FRONT or REAR LED
and SENS LED.  This LED should not light when a MOD
LED is on.

"MOD" LED

This red LED illuminates and latches on to indicate a
permanent or intermittent open or short circuit in the
solenoids of one of the two modulators or the wiring
connecting them to the system.  The MOD LED will illuminate
in conjunction with either the FRONT or REAR LED.

"SENS" LED

This red LED illuminates and latches on to indicate
permanent or intermittent problem.  The faults indicated are;
open or shorted wheel speed sensor, open or shorted wheel
speed sensor wiring, wheel speed signal not present or does
not conform to design criteria.  The SENS LED will illuminate
in conjunction with either the FRONT or REAR and either
the RIGHT or LEFT LED.

"ECU" LED

This red LED, when illuminated, indicates that the controller
itself has failed. It is latched on for all EC-14

 controller

faults except low voltage. For voltages less than 9 vdc, the
LED illuminates to indicate the controller is inoperative,
however when the voltage again exceeds 9 vdc the LED will
go out by itself.

"VOLT" LED

This green LED illuminates and remains on during vehicle
operation to indicate that vehicle power is reaching the
controller. If vehicle power is out of range for proper operation
(below 10 vdc or above 17 vdc) this LED will flash until power
is brought into range. This LED may also flash indicating
that a “marginal” low voltage condition existed at the time of
an antilock event.

"RESET"

Beneath the RESET area of the window display is a
magnetically sensitive switch that is used to reset the
diagnostic system.  The device will respond to a magnet
which has strength sufficient to lift a three (3) ounce weight.
Holding a magnet against the RESET will cause all LEDs to
light during the time the magnet is against it.

TROUBLESHOOTING

GENERAL

While the EC-14

 controller diagnostic display locates a

specific problem area, it is still necessary to confirm whether
the problem resides in the component itself or the wiring.
Basically the troubleshooting procedure that follows is
devoted to narrowing the problem to either the wiring or a
specific antilock component.  It should be noted that all
troubleshooting begins by observing the antilock status
lamp on the dash while performing the "Initial Start-
up Procedure"
 and following the directions contained in
the procedure.

IMPORTANT - TROUBLESHOOTING TIPS

1. Record all findings and the action taken during the

troubleshooting process. The record sheet should be
filed in the trailer maintenance folder for future reference
and comparison.

2. No voltage or resistance tests are performed into

the EC-14

 controller.  All voltage and resistance tests

are performed by beginning at the wire harness half of
the connector and moving away  from the EC-14

controller toward an antilock system component
(modulator, wheel speed sensor, etc.).

Содержание EC-14 ANTILOCK CONTROLLER

Страница 1: ...system are contained in a die cast aluminum housing and are environmentally protected by silicone encapsulation The metal housing coupled with the design of the digital electronics is intended to pro...

Страница 2: ...2 FIGURE 2 MC 14 ANTILOCK BRAKE SYSTEM...

Страница 3: ...l speed information from various wheel speed sensor models at the rate of 100 pulses per wheel revolution The EC 14 controller is able to simultaneously receive and individually interpret speed signal...

Страница 4: ...ONNECTOR DEUTSCH 2 PIN CONNECTOR 90 WS 20 WHEEL SPEED SENSOR STRAIGHT WS 20 WHEEL SPEED SENSOR BRAKE DRUM SPEED SENSOR MOUNTING BLOCK 100 TOOTH SPEED SENSOR EXCITER RING WS 20 WHEEL SPEED SENSOR 90 DE...

Страница 5: ...eans of advising the driver of the condition of the antilock system A connection to the Engine or Transmission Retarder is provided on the EC 14 controller which allows the EC 14 controller to tempora...

Страница 6: ...NON ANTILOCK BRAKE APPLICATION During normal braking the brake valve simultaneously delivers air to the control port of the M 12 modulator on the rear axle s as well as to and through the M 21 or M 22...

Страница 7: ...rformed during this period Because no two vehicles operate under identical conditions maintenance and maintenance intervals will vary Experience is a valuable guide in determining the best maintenance...

Страница 8: ...8 FIGURE 6 MC 14 ANTILOCK WIRING SCHEMATIC...

Страница 9: ...tion of the MC 14 modulator controller assembly on the vehicle Loosen remove and save the nuts on the mounting hardware that attaches the MC 14 modulator controller bracket to the vehicle Remove the M...

Страница 10: ...DS There are nine LEDs plus a magnetically actuated reset switch in the EC 14 controller diagnostic window The first five LEDs locate a problem to a specific area of the trailer while the last four in...

Страница 11: ...during vehicle operation to indicate that vehicle power is reaching the controller If vehicle power is out of range for proper operation below 10 vdc or above 17 vdc this LED will flash until power is...

Страница 12: ...odulators Go to Section I Dash Lamp Testing YES YES NO Dash lamp remains on NO Go to Section III Inspection for illuminated LEDs YES NO The system is functioning normally Make notes of the parts repla...

Страница 13: ...on on measure voltage between lamp relay Pin 3F and ground Pins 1A 2A Voltage should be same as battery voltage Replace the EC 14 controller Go to Section II Inspection for Illuminated LEDs Check wiri...

Страница 14: ...nspection for Illuminated LEDs NO Record the condition of all red LEDs Go to Section IX Testing for False Failure Indication Caused by Dash Lamp Relay NO Go to Section V Testing for Power to the EC 14...

Страница 15: ...lluminated Go to Section IV Inspection for Illuminated LEDs Record the condition of all red LEDs Go to Section X Testing For False Failure Indication Caused by Wheel Speed Components NO Go to Section...

Страница 16: ...NO Is the red FRONT or REAR LED illuminated See Note 1 below Is the red FRONT or REAR LED illuminated See Note 1 below NO YES REAR LED FRONT LED Go to Section VII Testing the Rear Modulator ON ON ON...

Страница 17: ...een power and ground pins on wire harness connector 1A to 1K 1A to 2K 2A to 1 K 2A to 2 K Reconnect connector to EC 14 controller Check the vehicle wiring for continuity Refer to the vehicle service m...

Страница 18: ...o Power 2F to 1K 2K No Continuity Exhaust to Ground 2F to 1A 2A No Continuity NO Go to Section VI B and continue testing Are resistance values correct 1A 2A GROUND 2F EXHAUST 2G HOLD 1K 2K POWER 1G SO...

Страница 19: ...Test each pin to vehicle ground and note no continuity Are resistance values correct Replace the front M 21 modulator NO Reconnect connector to modulator Turn ignition on and pass magnet over RESET o...

Страница 20: ...NET HERE YES STARTHERE Turn the ignition off Separate the EC 14 controller from the M 12 modulator Disconnect the four pin connector between the two components and test resistance on the modulator con...

Страница 21: ...If sensor gap must be adjusted check for loose or worn wheel bearings before re gapping sensor Refer to vehicle maintenance manual for worn bearings C If sensor gap is correct check wheel bearing for...

Страница 22: ...esistance between two pins on sensor Is resistance between 1500 2500 Ohms for the Bendix WS 20 speed sensor NO Replace the sensor YES NO Reconnect connector at speed sensor and EC 14 controller Pass m...

Страница 23: ...mation Repair or replace as necessary and repeat the Initial Start up Procedure Repeat the Initial Start up Procedure If testing has returned to this step twice replace the EC 14 controller and retest...

Страница 24: ...onds or more Bring vehicle to a stop and turn off ignition Turn the ignition off Refer to Section VII Part A Testing the wheel sensor and perform tests and inspections B through F in the large box Rep...

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