Bendix Commercial Vehicle Systems MC-12 MODULATOR CONTROLLER ASSY - Manual (Page 17)

17
Troubleshooting
SECTION VI PART B
TESTING THE WHEEL SPEED SENSOR
REPEAT THE “INITIAL
START-UP PROCEDURE”.
REPLACE THE EC-12 ™
CONTROLLER
YES
ARE ANY LED's ILLUMINATED?
YES
ARE SAME RED LEDS ILLUMINATED ?
YES
CORRECT RESISTANCE?
NO
DISCONNECT CONNECTOR AT SPEED SENSOR. INSPECT
THE CONNECTOR, THEN CHECK THE RESISTANCE BETWEEN
TWO PINS ON SENSOR. RESISTANCE BETWEEN 1500-2500
OHMS FOR THE BENDIX ® WS-20 ™ SPEED SENSOR
YES
REPLACE THE SENSOR
NO
NO
GO TO SECTION III "INSPECTION
FOR ILLUMINATED LED's"
NO
START HERE FROM
SECTION VI PART A GO TO SECTION III "INSPEC-
TION FOR ILLUMINATED LED's"
SAME LED's ILLUMINATED?
NO
YES
RECONNECT CONNECTOR AT SPEED
SENSOR AND EC-12 ™ CONTROLLER.
PASS MAGNET OVER "RESET" ON EC-12 ™
CONTROLLER. REMOVE MAGNET AND
OBSERVE LEDs
IGNITION OFF SERVICE BRAKES NOT APPLIED. REMOVE 14
PIN CONNECTOR FROM EC-12 ™ CONTROLLER. MEASURE
RESISTANCE BETWEEN SPEED SENSOR PINS M & L AND N & P ON
CONNECTOR. RESISTANCE FOR BENDIX® WS-20™ SPEED
SENSOR IS BETWEEN 1500-2500 OHMS. REFER TO VEHICLE
MANUAL FOR THE RESISTANCE VALUES IF OTHER THAN
WS-20™ SPEED SENSOR IS IN USE.
REPAIR OR REPLACE SPEED
SENSOR WIRING HARNESS
AND REPEAT THE “INITIAL
START-UP PROCEDURE”.
A B C D E F G H J K L M N P
M -SNS 2
L-SNS 2
N-SNS 1
P-SNS 1
TESTING SPEED SENSOR RESISTANCE
MAGNET HERE
RESETTING
EC-12 ™ CONTROLLER
EC-12 ™ CONTROLLER WIRE
HARNESS CONNECTOR