Abs Circuit Check

Disconnect ABS control unit 55-pin connector to perform circuit test. This test is to check integrity of ABS circuit and components. This quick check test could also be used to check for intermittent problems. With DVOM connected, perform wiring harness "wiggle" test to check for poor wiring harness or harness connections. Perform wiggle test while observing DVOM and shake or "wiggle" related wiring harness. See ABS CIRCUIT QUICK CHECK CHART and 55-PIN CONNECTOR TERMINAL IDENTIFICATION TABLE.

ABS CIRCUIT QUICK CHECK CHART

Circuit Test

Ignition Mode

Measure Between Terminals

Scale/ Range

Specification

ABS Control Unit Ground Check

Off

1 & Gnd

Ohms

Less Than One Ohm

Off

19 & Gnd

Ohms

Less Than One Ohm

Off

33 & Gnd

Ohms

Less Than One Ohm

Battery Power To ABS Control Unit

53 & 1

Volts

8V Minimum

Power From Main Relay ⁽¹⁾

33 & 1

Volts

⁽²⁾ 9.5V Minimum

Main Relay Coil

Off

34 & 53

Ohms

80-100 Ohms

Pump Motor Relay

Off

33 & 15

Ohms

42-58 Ohms

ABS Warning Light Ground ⁽³⁾

Off

33 & 1

Ohms

Less Than One Ohm

Front Right Isolation Solenoid Valve

Off

3 & 38

Ohms

5-8 Ohms

Front Left Isolation Solenoid Valve

Off

3 & 20

Ohms

5-8 Ohms

Rear Right Isolation Solenoid Valve

Off

3 & 55

Ohms

5-8 Ohms

Rear Left Isolation Solenoid Valve

Off

3 & 54

Ohms

5-8 Ohms

Front Right Dump Solenoid Valve

Off

3 & 21

Ohms

3-6 Ohms

Front Left Dump Solenoid Valve

Off

3 & 2

Ohms

3-6 Ohms

Rear Right Dump Solenoid Valve

Off

3 & 18

Ohms

3-6 Ohms

Rear Left Dump Solenoid Valve

Off

3 & 36

Ohms

3-6 Ohms

Front Right Wheel Speed Sensor

Off

29 & 47

k/ohms

1.0-1.4 k/ohms

Front Left Wheel Speed Sensor

Off

30 & 48

k/ohms

1.0-1.4 k/ohms

Rear Right Wheel Speed Sensor

Off

27 & 45

k/ohms

1.0-1.4 k/ohms

Rear Left Wheel Speed Sensor

Off

28 & 46

k/ohms

1.0-1.4 k/ohms

Pump Motor Speed Sensor

Off

31 & 49

Ohms

11-15 Ohms

Diode

Off

52 & 33

Diode Check

.5 Volts

⁽¹⁾	With terminals No. 1 and 34 jumped.

⁽²⁾	Ensure ABS warning light is not illuminated.

⁽³⁾	Ground through main relay.

55-PIN CONNECTOR TERMINAL IDENTIFICATION

Terminal No.	Wire Color
1	Black
2	Red
3	Yellow
15	Yellow/Blue
18	Blue/White
19	Black
20	Gray/Green
21	White/Brown
23	Yellow/Brown
27-30	Brown
31	Black
32	Gray/Black
33	White
34	Red/Blue
36	Black/Yellow
38	Black/Red
42	Red/Yellow
45-48	Black
49	Brown
52	Green/Red
53	Black/White
54	Violet
55	Green/Red