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Infiniti Q45. Manual - part 267

TROUBLE DIAGNOSIS

BRC-33

[VDC/TCS/ABS]

BRC

Pedal vibration or ABS operation sound occurs

Wheel sensor

BRC-59

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

Vehicle jerks during VDC/TCS/ABS control

VDC/TCS/ABS control unit

BRC-60

Unified ECM

Unified TCM

ABS warning lamp indication is not normal

CAN communication line

BRC-60

VDC/TCS/ABS control unit

Combination meter

SLIP indicator lamp is not normal

CAN communication line

BRC-61

VDC/TCS/ABS control unit

Combination meter

VDC OFF indicator lamp is not normal

CAN communication line

BRC-61

VDC/TCS/ABS control unit

Combination meter

Symptom

Check item

Reference Page

BRC-34

[VDC/TCS/ABS]

TROUBLE DIAGNOSIS

For Fast and Accurate Diagnosis

NFS000CW

PRECAUTIONS FOR DIAGNOSIS

●

Before performing diagnosis, always read GI section to confirm general precautions. Refer to

GI-3, "PRE-

CAUTIONS"

●

If steering angle sensor, steering system parts, suspension system parts, or tires have been replaced, or if
alignment has been adjusted, be sure to adjust neutral position of steering angle sensor before driving.
Refer to

BRC-6, "Adjustment of Steering Angle Sensor Neutral Position"

●

When replacing VDC/TCS/ABS control unit, be sure labels on control units are same color.

●

After diagnosis is finished, be sure to erase memory. Refer to

BRC-26, "How to Erase Self-Diagnostic

Results"

●

When checking continuity and voltage between units, be sure to check for disconnection, looseness,
bend, or collapse of connector terminals. If any malfunction is found, repair or replace connector termi-
nals.

●

For intermittent symptoms, possible cause is malfunction in harness, harness connector, or terminals.
Move harness, harness connector, and terminals to check for poor connections.

●

If a circuit tester is used for the check, be careful not to forcibly extend any connector terminal.

●

To use CONSULT-II to perform self-diagnosis of VDC/TCS/ABS control unit, active tests, or work support,
first stop work, then connect CONSULT-II and CONSULT-II CONVERTER to data link connector and
select “VDC”.

●

CONSULT-II self-diagnosis results are displayed without regard to occurrence timing. In some cases later
ones (timing value is small) appear on the next screen.

●

While self-diagnosis results of CONSULT-II shows a malfunction, if CONSULT-II active test is performed,
an engine system error may be indicated. In this case, start engine to resume normal screen.

●

VDC/TCS/ABS system electronically controls brake operation and engine output. Following symptoms
may be caused by normal operations:

Basic Inspection

NFS000HP

BRAKE FLUID LEVEL, LEAKAGE AND BRAKE PAD

Check fluid level in the brake fluid reservoir tank. Refill the brake fluid if fluid level is low.

Check the area around the brake piping and VDC actuator for leakage. If leakage or oozing is detected,
check as follows:

●

If actuator connections are loose, tighten piping to the specified torque. Check again for leakage, and
make sure that there is no fluid leakage.

Symptom

Symptom description

Result

Motor operation noise

This is noise of motor inside VDC actuator. Slight noise may occur during
VDC, TCS, and ABS operation.

Normal

Just after engine starts, motor operating noise may be heard. This is a nor-
mal status of the system operation check.

System operation check noise

When the engine starts, slight “click” noise may be heard from engine
room. This is normal and is part of system operation check.

Normal

TCS operation

(SLIP indicator lamp on)

TCS may activate momentarily if wheel speed changes when driving over
location where friction coefficient varies, when downshifting, or when fully
depressing accelerator pedal.

Normal

Cancel VDC/TCS func-

tion for the inspection

on a chassis dyna-

mometer.

When checking speed meter etc. with a 2-wheel-drive chassis dynamome-
ter, vehicle speed is not increased by pressing down on the accelerator.

ABS operation (Longer stop-

ping distance)

When driving on roads with a low coefficient of friction, such as snowy
roads or gravel roads, the stopping distance is sometimes longer for vehi-
cles equipped with ABS. Therefore, when driving on such roads, drive at a
sufficiently reduced speed to be safe.

Normal

Insufficient feeling of acceler-

ation

Depending on road conditions, driver may feel that feeling of acceleration
is insufficient. This is because traction control, which controls engine and
brakes to achieve optimal traction, has the highest priority (for safety). As a
result, there may be times when acceleration is slightly less than usual for
the same accelerator pedal operation.

Normal

TROUBLE DIAGNOSIS

BRC-35

[VDC/TCS/ABS]

BRC

●

If the flare nuts at the connections and the threads of the VDC actuator are damaged, replace the dam-
aged parts. Then check again for leakage, and make sure that there is no fluid leak.

●

If leakage or oozing is detected on parts other than VDC actuator connections, wipe with a clean cloth
and check again. If there is still leakage or oozing, replace the damaged part.

●

If leakage or oozing is detected on VDC actuator body, wipe with a clean cloth and check again. If there
is still leakage or oozing, replace VDC actuator.

CAUTION:

VDC actuator cannot be disassembled.

Check brake disc rotor and pads. Front disc rotor:

BR-28, "DISC ROTOR INSPECTION"

, Front pad:

BR-

23, "PAD WEAR INSPECTION"

, Rear disk rotor:

BR-33, "DISC ROTOR INSPECTION"

, Rear pad:

BR-

29, "PAD WEAR INSPECTION"

POWER SUPPLY CIRCUIT TERMINAL LOOSENESS AND BATTERY

Check battery for looseness on the battery positive/negative terminal and ground connection. Also make sure
that battery voltage does not drop.

ABS WARNING LAMP, VDC OFF INDICATOR LAMP, AND SLIP INDICATOR LAMP

: ON

–: OFF

Make sure that when the ignition switch is turned ON, the ABS warning lamp, VDC OFF indicator lamp
(when VDC OFF switch is off), and SLIP indicator lamp turn on, and that the brake warning lamp turns on.
If they do not turn on, perform CAN communication system diagnosis. Refer to

BRC-54, "CAN Communi-

cation Circuit"

. Be sure to check VDC OFF switch before checking VDC OFF indicator lamp. Refer to

BRC-54, "VDC OFF Switch"

. Check VDC OFF indicator lamp if there is no malfunction in CAN communi-

cation system and VDC OFF switch. Refer to

DI-7, "COMBINATION METERS"

Check if the ABS warning lamp, VDC OFF indicator lamp, and SLIP indicator lamp turn off after the igni-
tion switch is turned ON, and if the brake warning lamp turns off after the engine is started. If they do not
turn off, perform self-diagnosis.

With the engine running, make sure that the VDC OFF indicator lamp turns on and off when the
VDC OFF switch turns ON and OFF. If it does not operate in accordance with the switch, check the
VDC OFF switch system. Refer to

BRC-54, "VDC OFF Switch"

Perform self-diagnosis of VDC actuator if ABS warning lamp, VDC OFF indicator lamp, and SLIP indicator
lamp do not turn off 10 seconds after engine is started.

Always erase self-diagnostic results after completing self-diagnosis. Refer to

BRC-26, "How to Erase Self-

Diagnostic Results"

NOTE:
Brake warning lamp turns on during parking brake operation (when switch is “ON”) and brake fluid level switch
operation (insufficient brake fluid).

Condition

ABS warning lamp

VDC OFF

indicator lamp

SLIP indicator lamp

Ignition switch OFF

–

When ignition switch is turned
ON.

After ignition switch ON.

–

VDC OFF switch turned ON.
(VDC function is OFF.)

–

VDC/TCS function is malfunc-
tioning.

–

VDC/TCS/ABS function is
malfunctioning.

EBD function is malfunction-
ing.

BRC-36

[VDC/TCS/ABS]

TROUBLE DIAGNOSIS FOR SYSTEM

PFP:00000

Wheel Sensor

NFS000CY

INSPECTION PROCEDURE

CHECK SELF-DIAGNOSTIC RESULTS

With CONSULT-II

Turn ignition switch “ON”. (Do not start engine.)

Select “SELF-DIAG RESULTS” mode for “VDC” with CONSULT-II.

Touch “ERASE”.

Turn ignition switch “OFF” and wait at least 10 seconds.

Check the self-diagnostic results.

Is above displayed in the self-diagnosis display?

YES

>> GO TO 2.

>> INSPECTION END

CHECK TIRE

Check air pressure, wear and size.

Are air pressure, wear, and size within the standard values?

YES

>> GO TO 3.

>> Adjust air pressure, or replace tire.

CHECK SENSOR AND SENSOR ROTOR

●

Check the condition of the sensor mount (for looseness, etc.).

●

Check the surface of front sensor rotor for damage.

●

Check rear sensor rotor for damage.

OK or NG

>> GO TO 4.

>> Repair sensor mount or replace sensor rotor. Refer to

BRC-66, "SENSOR ROTOR"

CHECK CONNECTOR

Turn ignition switch “OFF”.

Disconnect VDC/TCS/ABS control unit connector E218 and malfunctioning wheel sensor connector E20
(FR-RH), E70 (FR-LH), B35 (RR-RH, RR-LH). Check terminal to see if it is deformed, disconnected,
loose, etc., Repair or replace it if any malfunction condition is found.

Reconnect connectors and then perform the self-diagnosis. Refer to

BRC-24, "SELF-DIAG RESULT

MODE"

OK or NG

>> INSPECTION END

>> GO TO 5.

Self-diagnosis results

FR RH SENSOR -1, -2

FR LH SENSOR -1, -2

RR RH SENSOR -1, -2

RR LH SENSOR -1, -2

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