Test readings, control-module connections
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Test readings, control-module connections
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The values and readings for measuring signals and levels in the ABS control module are given on the following pages.
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Observe the test conditions. Use common sense in assessing the readings.
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The readings presented are with the ignition ON unless otherwise stated.
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Start by checking that the control module is receiving power and is grounded.
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Check all sensor inputs and signals from other systems.
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Finally, check the control module outputs. Remember that the readings do not provide an indication that the actuator is operating.
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If any reading is not OK, consult the wiring diagram to trace the leads, connectors or components that need further checking.
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The specified readings are valid for a correctly calibrated Fluke 88/97.
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The readings %(+) and ms(+) indicate the pulse ratio and pulse length. A test instrument capable of measuring both pulse ratio and pulse length must be used. The '+' sign denotes a positive trigger pulse (TRIG+).
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Connection, test readings
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Important
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The readings apply to measurements taken on the control module's connector (unplugged) unless otherwise stated.
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> = greater than; < = less than; ~ = alternating current (LP: LOGIC PROBE P = select pulse; p = visible pulse)
Pin
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Cable colour
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Component/Function
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In/Out
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Test conditions
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Measure across
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Test reading
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See
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1
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YE
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Wheel sensor, RR: reference ground
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In
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Rotate the wheel one turn per second
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1-2
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>100 mV AC
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2
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BK
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Wheel sensor, RR: signal input
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In
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Rotate the wheel one turn per second
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2-1
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>100 mV AC
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3
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WH
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Wheel sensor, FR: reference ground
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In
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Rotate the wheel one turn per second
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3-5
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>100 mV AC
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4
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Spare
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5
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VT
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Wheel sensor, FR: signal input
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In
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Rotate the wheel one turn per second
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5-3
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>100 mV AC
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6
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BU
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Wheel sensor, FL: reference ground
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In
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Rotate the wheel one turn per second
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6-7
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>100 mV AC
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7
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RD
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Wheel sensor, FL: signal input
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In
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Rotate the wheel one turn per second
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7-6
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>100 mV AC
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8
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GY
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Wheel sensor, RL: reference ground
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In
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Rotate the wheel one turn per second
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8-9
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>100 mV AC
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9
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GH
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Wheel sensor, RL: signal input
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In
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Rotate the wheel one turn per second
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9-8
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>100 mV AC
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10
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Spare
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11
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WH/BK
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Data link
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In/Out
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12
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Spare
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13
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Spare
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14
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VT
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Brake-light switch
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In
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Brake pedal depressed
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14-16
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B+
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Brake pedal
released
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14-16
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0 V
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15
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YE/RD
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Current (+15 circuit)
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In
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15-B+
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<0.5 V
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16
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BK
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Pump-motor ground
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In
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16-B-
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<0.5 V
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17
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RD
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Current (+30 circuit)
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In
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17-B+
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<0.5 V
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18
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RD
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Current (+30 circuit)
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In
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18-B+
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<0.5 V
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19
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BK
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Ground
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In
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19-B-
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<0.5 V
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20
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Spare
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21
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GY/GN
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ABS warning lamp
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In
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21-B+
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<0.5 V
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22
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Spare
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23
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OG/WH
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Wheel speed, rear left
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Out
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Rotate wheel slowly
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0/approx. 12 V
Measure on MIU.
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Rotate the wheel one turn per second
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about 6 V
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24
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Spare
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25
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BK/GN
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Wheel Speed Front Left
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Out
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Rotate wheel slowly
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0/approx. 12 V
Measured in Cruise (not diesel)
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Rotate the wheel one turn per second
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About 6 V
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26
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PK/BK
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Wheel speed, front right
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Out
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Rotate wheel slowly
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0/approx. 12 V
Measured in engine management system
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Rotate the wheel one turn per second
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About 6 V
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