Infiniti Q45. Manual — part 273

TROUBLE DIAGNOSIS FOR SYSTEM

BRC-57

[VDC/TCS/ABS]

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BRC

VDC ACTUATOR

Turn ignition switch OFF and Disconnect VDC actuator connectors. Check continuity and resistance value
between any pair of terminals on the actuator.

CAUTION:

Make sure actuator motor is correctly grounded.
Continuity and resistance

Actuator Operation Inspection

●

Turn ignition switch OFF, apply a voltage of 12 V between VDC
relay box connector E56 terminal 5 and 8, use an oscilloscope
to measure motor voltage at this time (between terminal 4 and
ground), and check motor reverse voltage occurrence time
when operation is stopped.

CAUTION:

●

Above check should be performed after motor relay unit
inspection to make sure relay operates normally.

●

To prevent overheating, do not drive actuator motor more
than 4 seconds.

●

Motor reverse voltage occurrence time is standard when
battery voltage is 12 V and the air temperature is 20

°

C

(68

°

F), and this time is a little shorter when battery voltage

is low or the air temperature is low.

SFIA2339E

Item

VDC actuator connector terminal num-

ber

Continuity and Resistance

value

Condition

Solenoid valve

1, 3, 5, 7

19

6.0 - 11

Ω

Check the resistance

14, 15, 16, 17

3.0 - 5.0

Ω

VDC switch-over solenoid

valve

25, 26

6.0 - 11

Ω

27, 28

3.0 - 5.0

Ω

Actuator motor

21

ground

Yes

—

Motor counter electromotive force duration

: 0.1 second or more

SFIA3313E

BRC-58

[VDC/TCS/ABS]

TROUBLE DIAGNOSIS FOR SYMPTOMS

TROUBLE DIAGNOSIS FOR SYMPTOMS

PFP:00007

Excessive ABS Function Operation Frequency

NFS000DD

1.

CHECK ABS WARNING LAMP DISPLAY

Make sure the ABS warning lamp turns off after ignition switch is turned ON or when driving.

OK or NG

OK

>> GO TO 2.

NG

>> Perform self-diagnosis. Refer to

BRC-24, "SELF-DIAG RESULT MODE"

.

2.

CHECK BRAKE FORCE DISTRIBUTION

Check front and rear brake force distribution using a brake tester. Refer to

BR-35, "SERVICE DATA AND

SPECIFICATIONS (SDS)"

.

OK or NG

OK

>> GO TO 3.

NG

>> Check brake system.

3.

CHECK FRONT AND REAR AXLE

Make sure that there is no looseness in the front and rear axles. Refer to front axle

FAX-4, "WHEEL BEARING

INSPECTION"

, rear axle.

RAX-5, "WHEEL BEARING INSPECTION"

.

OK or NG

OK

>> GO TO 4.

NG

>> Axle inspection and repair

4.

CHECK WHEEL SENSOR AND SENSOR ROTOR

Check the following.

●

Wheel sensor installation and damage.

●

Sensor pick-up inspection for iron chips.

●

Sensor rotor installation and damage.

●

Wheel sensor connector connection.

●

Wheel sensor harness inspection.

OK or NG

OK

>> INSPECTION END.

NG

>> Repair wheel sensor and rotor system.

Unexpected Pedal Reaction

NFS000DE

1.

CHECK BRAKE PEDAL STROKE

Check brake pedal stroke. Refer to

BR-6, "Inspection and Adjustment"

.

Is the stroke too big?

YES

>>

●

Bleed air from brake piping. Refer to

BR-9, "Bleeding Brake System"

.

●

Check brake pedal, brake booster, and master cylinder mount for play, looseness, and brake
system for fluid leaks, etc. If any malfunctions are found, make repairs. Brake pedal:

BR-8,

"Removal and Installation"

. Brake master cylinder and Brake booster:

BR-21, "Removal and

Installation"

.

NO

>> GO TO 2.

TROUBLE DIAGNOSIS FOR SYMPTOMS

BRC-59

[VDC/TCS/ABS]

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BRC

2.

CHECK FUNCTION

Disconnect VDC/TCS/ABS control unit connector, and make sure the braking force is sufficient when the ABS
is not operating. After the inspection, reconnect connector.

OK or NG

OK

>> GO TO 4. “CHECK WHEEL SENSOR AND SENSOR ROTOR” in

BRC-58, "Excessive ABS

Function Operation Frequency"

.

NG

>> Check brake system.

The Braking Distance Is Long

NFS000DF

CAUTION:

On slippery road surfaces, the stopping distance might be longer with the ABS operating than when
the ABS is not operating.

1.

CHECK FUNCTION

1.

Turn ignition switch “OFF”.

2.

Disconnect VDC/TCS/ABS control unit connector to deactivate ABS. In this condition, check stopping dis-
tance. After inspection, connect connector.

OK or NG

OK

>> Go to “CHECK WHEEL SENSOR AND SENSOR ROTOR” in

BRC-58, "Excessive ABS Function

Operation Frequency"

.

NG

>>

●

Bleed air from brake piping. Refer to

BR-9, "Bleeding Brake System"

.

●

Check brake system.

The ABS Function Does Not Operate

NFS000DG

CAUTION:

The ABS does not operate when the speed is 10 km/h (6 MPH) or less.

1.

CHECK ABS WARNING LAMP DISPLAY

Make sure ABS warning lamp turns off after ignition switch is turned ON or when driving.

OK or NG

OK

>> Go to “CHECK WHEEL SENSOR AND SENSOR ROTOR” in

BRC-58, "Excessive ABS Function

Operation Frequency"

.

NG

>> Perform self-diagnosis. Refer to

BRC-24, "SELF-DIAG RESULT MODE"

.

Pedal Vibration or ABS Operation Sound Occurs

NFS000DH

CAUTION:

Under the following conditions, when brake pedal is lightly depressed (just place a foot on it), ABS is
activated and vibration is felt. However, this is normal.

●

When shifting gears

●

When driving on slippery road

●

During cornering at high speed

●

When passing over bumps or grooves [50 mm (1.97 in) or more]

●

When pulling away just after starting engine [at approximately 10 km/h (6 MPH) or higher]

1.

SYMPTOM CHECK 1

Check if pedal vibration or operation sound occurs when engine is started.

OK or NG

OK

>> GO TO 2.

NG

>> Perform self-diagnosis. Refer to

BRC-24, "SELF-DIAG RESULT MODE"

.

BRC-60

[VDC/TCS/ABS]

TROUBLE DIAGNOSIS FOR SYMPTOMS

2.

SYMPTOM CHECK 2

Check the symptom when electrical component (headlamps, etc.) Switches are operated.

Does the symptom occur when the electrical component (head lamp, etc.) Switches are operated?

YES

>> Check if there is a radio, antenna, antenna lead wire, or wiring close to control unit (or its wiring),

and if there is, move it farther away.

NO

>> Go to “CHECK WHEEL SENSOR AND SENSOR ROTOR” in

BRC-58, "Excessive ABS Function

Operation Frequency"

.

Vehicle Jerks During VDC/TCS/ABS Control

NFS000DI

1.

CHECK SELF-DIAGNOSTIC RESULTS

Perform self-diagnosis of VDC/TCS/ABS control unit.

Are self-diagnostic results indicated?

YES

>> Check the corresponding items, make repairs, and perform VDC/TCS/ABS control unit self-diag-

nosis.

NO

>> GO TO 2.

2.

CHECK VDC/TCS/ABS CONTROL UNIT

Check VDC/TCS/ABS control unit input/output signal. Refer to

BRC-22, "Control Unit Input/Output Signal

Standard"

.

OK or NG

OK

>> GO TO 3.

NG

>> Check VDC/TCS/ABS control unit pin terminals for damage or loose connection with harness con-

nector. If any item is damaged, repair or replace damaged parts.

3.

CHECK ECM AND TCM SELF-DIAGNOSTIC RESULTS

Perform ECM and TCM self-diagnosis.

Are self-diagnostic results indicated?

YES

>>

●

Check the corresponding items.

–

ECM: Refer to

EC-82, "TROUBLE DIAGNOSIS"

.

–

TCM: Refer to

AT-42, "TROUBLE DIAGNOSIS"

.

NO

>> Replace VDC actuator.

ABS Warning Lamp Indication Is Not Normal

NFS000DJ

NOTE:
For lighting condition of ABS warning lamp. Refer to

BRC-35, "ABS WARNING LAMP, VDC OFF INDICATOR

LAMP, AND SLIP INDICATOR LAMP"

.

1.

CHECK SYSTEM FOR CAN COMMUNICATION LINE

Perform self-diagnosis. Refer to

BRC-24, "SELF-DIAG RESULT MODE"

.

Is the “CAN COMM CIRCUIT” displayed?

YES

>> Perform trouble diagnosis for CAN communication line. Refer to

BRC-54, "CAN Communication

Circuit"

.

NO

>> GO TO 2.

2.

CHECK VDC/TCS/ABS CONTROL UNIT

Check VDC/TCS/ABS control unit input/output signal. Refer to

BRC-22, "Control Unit Input/Output Signal

Standard"

.

OK or NG

OK

>> GO TO 3.

NG

>> Check VDC/TCS/ABS control unit pin terminals for damage or loose connection with harness con-

nector. If any item is damaged, repair or replace damaged parts.