Chart D5, Pressure SWTCH Performance

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This chart is to be used as directed during ABS FUNCTIONAL CHECK.

Fig 1: Flow Chart D-5, Pressure Switch Performance (1 of 2)

Courtesy of GENERAL MOTOR CO.

This chart is to be used as directed during ABS FUNCTIONAL CHECK.

Fig 2: Flow Chart D-5, Pressure Switch Performance (2 of 2)

Courtesy of GENERAL MOTOR CO.

I. Switch Status - Pressurized

Turn Ignition To Run Until Pump Stops
Ignition Off
NOTE: If Pump Continues To Run After 45 Seconds, Turn Ignition Off And Proceed.

Check Pressure Switch Pins For The Following Conditions Using DVOM:

SWITCH STATUS - PRESSURIZED

Measure Between Pins	Scale	Specification
B, D	200 Ohms	No Continuity
A, D	200 Ohms	No Continuity
C, E	200 Ohms	Continuity
All Pins, Body Ground	200 Ohms	No Continuity

If Any Condition Is Not Met, Replace Pressure Switch And Verify System Operation

II. Switch Status - Depressurized

Depressurize Accumulator
Check Pressure Switch Pins For The Following Conditions Using DVOM:

SWITCH STATUS - DEPRESSURIZED

Measure Between Pins	Scale	Specification
B, D	200 Ohms	Continuity
A, D	200 Ohms	Continuity
C, E	200 Ohms	No Continuity
All Pins, Body Ground	200 Ohms	No Continuity

III. Switch Status - Pressurized

Depressurize Hydraulic Accumulator
Install Pressure Gage J-35604-88
Connect Pressure Switch Connector And Turn Ignition To Run Until Pump Stops
Using DVOM, Monitor For Continuity Between Pressure Switch Pins As Shown Below While Slowly Bleeding Off Accumulator Pressure By Pumping Brake Pedal

Pressurize System Between Each Test By Reconnecting Pressure Switch And Turning Ignition To Run Until Pump Stops

SWITCH STATUS - PRESSURIZED

Measure Between Pins	Scale	Specification
A, D	Continuity Should Be Gained At:	2,001-2,008 Psi (13,800-14,400 kPa)
B, D	Continuity Should Be Gained At:	1,465-1,552 Psi (10,103-10,703 kPa)
C, E	Continuity Should Be Gained At:	1,465-1,552 Psi (10,103-10,703 kPa)

If Any Condition Is Not Met, Replace Pressure Switch And Verify Operation
Depressurize Hydraulic Accumulator
With Ignition Off, Connect Pressure Switch Connector

Turn Ignition To Run And Observe Gage, "Anti-Lock" Lamp, "Brake" Lamp And Pump Motor, Events Should Occur At Pressures Indicated In Chart Below:

SWITCH EVENT PRESSURE

Event	Pressure
"Anti-Lock" Lamp Turn Off	1,937-2,037 Psi (13,358-14,048 kPa)
"Brake" Lamp Turn Off	1,937-2,037 Psi (13,358-14,048 kPa)
Pump Motor Stops	2,494-2,755 Psi (17,200-19,000 kPa)

If Any Condition Is Not Met, Replace Pressure Switch And Verify System Operation