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Ford Ranger EV (2001 year). Manual - part 38

206-07-2

Power Brake Actuation

SPECIFICATIONS

Torque Specifications

Description

Lb-Ft

Lb-In

Description

Lb-Ft

Lb-In

Vacuum Pressure Sensor

5.5

—

Battery Ground Cable

—

to Vacuum Tee Screws

Vacuum Pump Bracket

—

Vacuum Pressure Sensor

—

Bolts

Bolt

(Continued)

The vacuum pressure sensor measures absolute

DESCRIPTION AND OPERATION

pressure. The IAA module reports pressure in the

Power Disc Brake Actuation

system as the difference between system pressure

Card Table Bottom View

and absolute zero pressure. Based upon the absolute
zero scale, ambient pressure is about 100 kPa (14.5
psi). Any pressure less than 100 kPa (14.5 psi) is
defined as vacuum. The smaller the reading, the
higher the amount of vacuum.

Power is supplied to the vacuum pump when the
key is in the RUN or START position. The IAA
module reads the vacuum signal sent by the vacuum
pressure sensor and opens and closes a relay to
operate the vacuum pump. The vacuum pump cycles
in order to maintain a set amount of pressure that
ranges from 26-34 kPa (3.8-4.9 psi).

Item

Part Number

Description

—

Card Table

—

Vacuum Pump

—

Vacuum Pressure Sensor

The Electric Vehicle uses a conventional
vacuum-assisted hydraulic brake system. All
vacuum necessary for the brake system and climate
control operation is supplied by an electrically
operated vacuum pump. The pump is driven by an
electric motor and is controlled by the interface
adapter assembly (IAA) module. A vacuum signal is
sent to the IAA module from a vacuum pressure
sensor located in the vacuum line from the pump.
The pump and the vacuum pressure sensor are
mounted on the bottom side of the card table,
underneath the traction battery charger. The vacuum
pump should be replaced every 5 years or 60,000
miles.

206-07-3

Power Brake Actuation

Electrical Schematic

DIAGNOSIS AND TESTING

Vacuum System

Refer to Electrical and Vacuum Troubleshooting
Manual, Cell 139, Vacuum System for schematic

Diagnostic Trouble Code (DTC) Definition

and connector information.

The following DTC relates to the vacuum system:

Inspection and Verification

•

DTC C1777 Vacuum Pressure Circuit Failure

Refer to

Section 100-07

— The interface adapter assembly (IAA) module

uses the vacuum pressure sensor to monitor
the pressure in the vacuum system. The
normal operating pressure of the vacuum
system is 26-34 kPa (3.8-4.9 psia). The
normal range of the vacuum pressure sensor
is 15-105 kPa (2.2-15.2 psia). The IAA
module sets DTC C1777 if the brake pedal
has not been pressed for 30 seconds and the
vacuum pressure is less than 15 kPa (2.2 psia)
or if the brake pedal has not been pressed and
the vacuum pump has run continuously for
more than five minutes. DTC C1777 is also
set if the vacuum pressure is greater than 93.5
kPa (13.6 psia) and the vacuum pump has run
continuously for more than five minutes. If
this occurs, the IAA module operates the
vacuum pump at limited operating strategy
(LOS) mode defined as six seconds every two
minutes, and for a preset time each time the
brake pedal is depressed or released.

Symptom Chart

Condition

Possible Sources

Action

•

DTC C1777 Vacuum Pressure

•

Fuse.

•

GO to

Pinpoint Test A.

Circuit Failure

•

Circuit(s).

•

Vacuum pump.

•

Vacuum pump relay.

•

Vacuum pressure sensor.

•

Interface adapter assembly
(IAA) module.

•

Excessive Brake Pedal Effort

•

Vacuum pump.

•

GO to

Pinpoint Test B.

to Stop Vehicle

•

Mechanical brake system.

•

Vacuum Pump Cycles on and

•

Climate control vacuum

•

GO to

Pinpoint Test C.

off Without Brake Pedal or

system.

Climate Control Activation

•

Brake booster.

(Vacuum System Leak Test)

•

Brake booster check valve.

•

Brake booster vacuum hose.

•

Vacuum tee assembly.

206-07-4

Power Brake Actuation

DIAGNOSIS AND TESTING (Continued)

Symptom Chart (Continued)

Condition

Possible Sources

Action

•

Vacuum Pump Exhibits

•

Vacuum pump.

•

GO to

Pinpoint Test D.

Unusual or Excessive Noise

•

Incorrect vacuum pump
bracket bolt torque
specifications.

•

Incorrect vacuum pump
installation.

Pinpoint Tests

Special Tool(s)

104-Pin Breakout Box (BOB) 418-049 (014-00950) or

equivalent

PINPOINT TEST A: DTC C1777 VACUUM PRESSURE CIRCUIT FAILURE

TEST STEP

ACTION TO TAKE

A1 IDENTIFY SYMPTOM

•

With key ON, depress the brake pedal.

Yes

GO to A12.

NOTE: DTC C1777 is set if the vacuum pump does not operate, runs

No =

GO to A2.

continuously without cycling on and off, or cycles on and off without brake
pedal or climate control activation.

•

Identify the symptom of the vacuum system operation.

•

Does the vacuum pump operate?

A2 CHECK VACUUM PUMP OPERATION

•

Enter the interface adapter assembly (IAA) module active command mode

Yes

GO to A3.

THERMAL REGULATION OUTPUT CONTROL and set the active

command VAC RLY to ON.

•

Does the vacuum pump operate?

No =

GO to A6.

A3 CHECK INTERFACE ADAPTER ASSEMBLY (IAA) MODULE

•

With key OFF, disconnect vacuum pressure sensor C1997.

Yes

GO to A4.

•

Connect 104-Pin Breakout Box (BOB) to the IAA module and IAA module

No =

REPLACE the IAA module.

C1945.

REFER to

Section 412-04

•

With key ON, monitor the IAA module PID VACPRES.

•

Connect a jumper wire between BOB pins 4 and 88.

•

Does the VACPRES PID indicate greater than 80 kPa (11.6 psi)?

A4 CHECK CIRCUITS 3032 (DB/LG) AND 3033 (BK/LB) FOR OPEN(S)

•

With key OFF, measure the resistance of the DB/LG wire between vacuum

Yes

GO to A5.

pressure sensor C1997 and BOB pin 4.

•

With key OFF, measure the resistance of the BK/LB wire between vacuum

No =

REPAIR the wire(s) in

pressure sensor C1997 and BOB pin 88.

question.

•

Are the resistances less than 5 ohms?

A5 CHECK CIRCUITS 3032 (DB/LG) AND 3033 (BK/LB) FOR SHORT(S)
TO GROUND

•

With key OFF, disconnect the IAA module from the BOB; leave BOB

Yes

REPLACE the vacuum

connected to IAA module C1945.

pressure sensor.

•

With key OFF, measure the resistance between BOB pins 4, 88 and ground.

No =

REPAIR the wire(s) in

•

Are the resistances greater than 10,000 ohms?

question.

A6 CHECK FUSE AND POWER TO VACUUM PUMP RELAY

•

With key OFF, check 20A fuse 13 in the electric vehicle power distribution

Yes

RECONNECT the vacuum

box (EVPDB).

pump relay. GO to A7.

(Continued)

206-07-5

Power Brake Actuation

DIAGNOSIS AND TESTING (Continued)

PINPOINT TEST A: DTC C1777 VACUUM PRESSURE CIRCUIT FAILURE

TEST STEP

ACTION TO TAKE

•

With key OFF, remove the vacuum pump relay from the EVPDB and

No =

REPAIR as necessary.

measure the voltage between pins 1, 3 on the vacuum pump relay connector
and ground. (V > 10 volts)

•

Is everything OK?

A7 CHECK POWER TO VACUUM PUMP

•

With key OFF, disconnect vacuum pump C1996.

Yes

REPLACE the vacuum

pump.

•

Enter the IAA module active command mode THERMAL REGULATION

No =

GO to A8.

OUTPUT CONTROL, set the active command VAC RLY to ON, and
measure the voltage between the LB/O wire and BK wire on vacuum pump
C1996.

•

Is the voltage greater than 10 volts?

A8 CHECK GROUND TO VACUUM PUMP

•

With key OFF, measure the resistance between the BK wire on vacuum

Yes

GO to A9.

pump C1996 and ground.

•

Is the resistance less than 5 ohms?

No =

REPAIR the BK wire.

A9 CHECK VACUUM PUMP RELAY CONTROL CIRCUIT

•

With key OFF, remove the vacuum pump relay from the EVPDB.

Yes

GO to A11.

•

Enter the IAA module active command mode THERMAL REGULATION

No =

GO to A10.

OUTPUT CONTROL, set the active command VAC RLY to ON, and
measure the resistance between pin 2 on the vacuum pump relay connector
and ground.

•

Is the resistance less than 5 ohms?

A10 CHECK CIRCUIT 3021 (GY/BK) FOR OPEN

•

Connect 104-Pin Breakout Box (BOB) to IAA module C1945; leave IAA

Yes

REPLACE the IAA module.

module disconnected.

REFER to

Section 412-04.

•

With key OFF, measure the resistance of the GY/BK wire between pin 2 on

No =

REPAIR the GY/BK wire.

the vacuum pump relay connector and BOB pin 30.

•

Is the resistance less than 5 ohms?

A11 CHECK CIRCUIT 3230 (LB/O) FOR OPEN

•

With key OFF, measure the resistance of the LB/O wire between vacuum

Yes

REPLACE the vacuum

pump C1996 and pin 5 on the vacuum pump relay connector.

pump relay.

•

Is the resistance less than 5 ohms?

No =

REPAIR the LB/O wire.

A12 CHECK VACUUM PRESSURE

•

With key ON, monitor the interface adapter assembly (IAA) module PID

Yes

GO to A13.

VACPRES.

•

Is the VACPRES PID less than 18 kPa (2.6 psi)?

No =

If VACPRES PID is greater
than 80 kPa (11.6 psi) and
is not fluctuating, GO to
A16.

If VACPRES PID is greater
than 80 kPa (11.6 psi) and
is fluctuating, CHECK for
vacuum system leaks. GO to

Pinpoint Test C.

A13 CHECK CIRCUIT 3230 (LB/O) FOR SHORT TO POWER

•

Remove the vacuum pump relay from the electric vehicle power distribution

Yes

GO to A14.

box (EVPDB).

•

Does the vacuum pump stop running?

No =

REPAIR the LB/O wire.

A14 CHECK VACUUM PUMP RELAY

(Continued)

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