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Infiniti Q45 (FY33). Manual - part 101

SBR540A

Diagnostic Procedure 29
(Unexpected pedal action)

SBR698D

Check brake pedal stroke. Is stroke
excessively large?

Yes

Perform Preliminary
Check, refer to BR-48.

Disconnect ABS actuator 8-pin connector
and check whether brake is effective.

Yes

Perform Preliminary
Check, refer to BR-48.

Ensure ABS warning lamp remains off
while driving.

Carry out self-diagnosis.
Refer to BR-59, 63.

CHECK WHEEL SENSOR.

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

1. Check wheel sensor connector for ter-

minal damage or loose connection.

2. Perform wheel sensor mechanical

check.
Refer to

and

in Diagnostic Pro-

cedure 7, BR-88.

Repair.

Check control unit pin terminals for dam-
age or the connection of control unit har-
ness connector.
Reconnect control unit harness connector.
Then retest.

Diagnostic Procedure 30
(Long stopping distance)

Disconnect ABS actuator 8-pin connector
and check whether stopping distance is
still long.

Yes

Go to

in Diagnostic

Procedure 29, BR-121.

Perform Preliminary Check and air bleed-
ing.

Note: Stopping distance may be larger than vehicles without

ABS when road condition is slippery.

IDX

TROUBLE DIAGNOSES FOR SYMPTOMS

BR-121

Diagnostic Procedure 31
(ABS does not work.)

Does the ABS warning lamp activate?

Yes

Carry out self-diagnosis.
Refer to BR-59, 63.

Go to

in Diagnostic Procedure 29,

BR-121.

Note: ABS does not work when vehicle speed is under 10 km/h

(6 MPH).

SAT797A

Diagnostic Procedure 32
(Pedal vibration and noise)

1. Apply brake.
2. Start engine.
3. Does the symptom appear only when

engine is started?

Yes

Carry out self-diagnosis.
Refer to BR-59, 63.

Does the symptom appear when electrical
equipment switches (such as headlamp)
are operated?

Yes

Go to

in Diagnostic

Procedure 29, BR-121.

Check wheel sensor shield ground. For
location of shield ground, refer to EL
section, “Wiring Diagram” and “HARNESS
LAYOUT”.

Repair.

Check control unit pin terminals for dam-
age or the connection of control unit har-
ness connector.
Reconnect control unit harness connector.
Then retest.

Note: ABS may operate and cause vibration under any of the

following conditions.

Applying brake gradually when shifting or operating
clutch.

Low friction (slippery) road.

High speed cornering.

Driving over bumps and pot holes.

Engine speed is over 5,000 rpm with vehicle stopped.

TROUBLE DIAGNOSES FOR SYMPTOMS

BR-122

SBR699DB

Electrical Component Inspection

INSPECTION OF ABS/TCS CONTROL UNIT

Check that voltage between ABS/TCS control unit terminals is
within the following reference value.

Pin connector terminal layout.

SBR406E

ABS/TCS control unit inspection table

TERMINAL NO.

ITEM

CONDITION

DATA (Reference value)

−

108

Ground

Power source

Ignition switch “ON”

Battery voltage

Stop lamp switch signal

Brake pedal depressed

Approx. 12V

Brake pedal released

Less than 2V

Motor relay

ABS actuator motor operating
(Perform “ACTIVE TEST” mode with CON-
SULT-II.)
Engine running

Less than 2V

ABS actuator motor not operating

Approx. 12V

Actuator relay

ABS actuator relay operating (Engine is
running.)

Less than 2V

ABS actuator relay not operating (Ignition
switch “ON”)

Approx. 12V

Actuator monitor

ABS actuator relay operating (Engine is
running.)

Approx. 12V

ABS actuator relay not operating (Ignition
switch “ON”)

Approx. 0V

101

Front solenoid valve RH IN

ABS actuator operating (Perform “ACTIVE
TEST” mode with CONSULT-II.)
Engine running

Approx. 0V

102

Rear solenoid valve IN

103

Front solenoid valve LH IN

ABS actuator not operating (Engine is run-
ning with vehicle stopped.)

Approx. 12V

Motor monitor

ABS actuator motor operating (Perform
“ACTIVE TEST” mode with CONSULT-II.)
Engine running

Approx. 12V

ABS actuator motor not operating

Approx. 0V

ABS warning lamp

ABS warning lamp “ON”*1

Approx. 0V

ABS warning lamp “OFF”*1

Approx. 12V

IDX

TROUBLE DIAGNOSES FOR SYMPTOMS

BR-123

TERMINAL NO.

ITEM

CONDITION

DATA (Reference value)

−

Front wheel sensor RH

Wheel is rotating
[Drive vehicle at 30 km/h (19 MPH).]*2

Approx. 0.1 - 0.2V
Approx. 200 Hz*3

Rear wheel sensor RH

Approx. 0.1 - 0.2V
Approx. 200 Hz*3

Rear wheel sensor LH

Front wheel sensor LH

Approx. 0.1 - 0.2V
Approx. 200 Hz*3

Ground

Engine speed signal*4

Engine running at idle speed

Approx. 2.5V

Engine running at 2,000 rpm

Approx. 2.4V

104

Front solenoid valve RH OUT

ABS actuator operating (Perform “ACTIVE
TEST” mode with CONSULT-II.)
Engine running

Approx. 0V

105

Rear solenoid valve OUT

106

Front solenoid valve LH OUT

ABS actuator not operating (Engine is run-
ning with vehicle stopped.)

Approx. 12V

Body

ground

TCS OFF switch signal

TCS OFF switch pressed
TCS OFF switch released

Approx. 0V
Approx. 4 - 5V

TCS OFF indicator

TCS OFF indicator ON*5
TCS OFF indicator OFF

0V
Approx. 12V (Power
source voltage)

SLIP indicator

SLIP indicator ON*6
SLIP indicator OFF

0V
Approx. 12V (Power
source voltage)

Throttle valve opening rate signal

SBR701D

—

Secondary throttle valve opening rate
target

SBR701D

—

LAN signal

SBR702D

—

NOTE:
*1: ABS warning lamp ON-OFF timing

ON - ignition switch “ON” (before engine starts) or when failure is sensed.
OFF - After engine starts (System in good operating condition)

*2: Inflate tires to specifications.
*3: Use oscilloscope checking, when pulse occurs.
*4: Refer to “ECM terminals and reference value” in EC section.
*5: TCS OFF indicator ON-OFF timing

ON - ignition switch “ON” (before engine starts) or failure is sensed (TCS OFF switch “ON”)
OFF - After engine starts (System in good operating condition) and TCS OFF switch “OFF”

*6: SLIP indicator ON-OFF timing

ON - ignition switch “ON” (before engine starts) or TCS in operation
OFF - After engine starts and when TCS not operating

TROUBLE DIAGNOSES FOR SYMPTOMS

Electrical Component Inspection (Cont’d)

BR-124

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