2006 INFINITI QX56 relay

BRC-1
BRAKE CONTROL SYSTEM
F BRAKES
CONTENTS
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G H
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SECTION
A
B
BRC
Revision: November 2009 2006 QX56VDC/TCS/ABS
PRECAUTIONS .......................................................... 3
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” ............................................................. ..... 3
Precautions for Brake System ............................. ..... 3
Precautions When Using CONSULT-II ................ ..... 3
CHECK POINTS FOR USING CONSULT-II .... ..... 3
Precautions for Brake Control ............................. ..... 4
Precautions for CAN System .............................. ..... 4
PREPARATION ...................................................... ..... 6
Special Service Tool ............................................ ..... 6
Commercial Service Tools ................................... ..... 6
SYSTEM DESCRIPTION ............................................ 7 System Components ........................................... ..... 7
ABS Function ........................................................... 8
EBD Function ...................................................... ..... 8
TCS Function ...................................................... ..... 8
VDC Function ...................................................... ..... 8
Fail-Safe Function .................................................... 8 ABS/EBD SYSTEM .......................................... ..... 9
VDC/TCS SYSTEM .......................................... ..... 9
ACTIVE BOOSTER .......................................... ..... 9
Hydraulic Circuit Diagram ................................... ..... 9
CAN COMMUNICATION ....................................... ... 10
System Description ............................................. ... 10
TROUBLE DIAGNOSIS ......................................... ....11
How to Perform Trouble Diagnoses for Quick and
Accurate Repair .................................................. .... 11
INTRODUCTION .............................................. .... 11
WORK FLOW ................................................... ... 12
CLARIFY CONCERN ....................................... ... 13
EXAMPLE OF DIAGNOSIS SHEET ................ ... 13
Component Parts and Harness Connector Location ... 14
Schematic ........................................................... ... 15
Wiring Diagram — VDC — .................................. ... 16
Basic Inspection .................................................. ... 23
BRAKE FLUID LEVEL, FLUID LEAK, AND
BRAKE PAD INSPECTION .............................. ... 23
POWER SYSTEM TERMINAL LOOSENESS AND BATTERY INSPECTION ..........................
... 23
ABS WARNING LAMP, SLIP INDICATOR LAMP
AND VDC OFF INDICATOR LAMP INSPECTION ... 23
Warning Lamp and Indicator Timing .................... ... 24
Control Unit Input/Output Signal Standard .......... ... 24
REFERENCE VALUE FROM CONSULT-II ...... ... 24
CONSULT-II Function (ABS) ............................... ... 28
CONSULT-II BASIC OPERATION PROCEDURE ... 28
SELF-DIAGNOSIS ........................................... ... 29
DATA MONITOR .............................................. ... 32
ACTIVE TEST ..................................................... 35
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC
ITEMS ..................................................................... ... 38
Wheel Sensor System Inspection ........................ ... 38
Engine System Inspection ................................... ... 39
ABS/TCS/VDC Control Unit Inspection ............... ... 40
Steering Angle Sensor System ............................ ... 40
Yaw Rate/Side/Decel G Sensor System Inspection ... 41
Solenoid and VDC Change-Over Valve System
Inspection ............................................................ ... 43
Actuator Motor, Motor Relay, and Circuit Inspection ... 44
Stop Lamp Switch System Inspection ................. ... 45
ABS/TCS/VDC Control Unit Power and Ground
Systems Inspection ............................................. ... 46
Brake Fluid Level Switch System Inspection ....... ... 47
Active Booster System Inspection ....................... ... 48
Delta Stroke Sensor System Inspection .............. ... 49
Pressure Sensor System Inspection ................... ... 51
Steering Angle Sensor Safe Mode Inspection ..... ... 53
CAN Communication System Inspection ............. ... 54
ICC System Inspection ........................................ ... 54
Inspection For Self-diagnosis Result "ST ANG SEN
SIGNAL" .............................................................. ... 55
Inspection For Self-diagnosis Result "DECEL G
SEN SET" ............................................................ ... 55
VDC OFF Indicator lamp Does Not Illuminate ..... ... 56
Component Inspection ......................................... ... 56
VDC OFF SWITCH .......................................... ... 56

TROUBLE DIAGNOSISBRC-25
[VDC/TCS/ABS]
C
DE
G H
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K L
M A
B
BRC
Revision: November 2009 2006 QX56
STR ANGLE SIGSteering angle
detected by steering
angle sensorStraight-ahead
Approx. 0 deg
BRC-40, "Steering Angle
Sensor System"Steering wheel turned –756 to 756 deg
YAW RATE SEN Yaw rate detected by
yaw rate sensorVehicle stopped Approx. 0 d/s
BRC-41, "
Yaw Rate/Side/
Decel G Sensor System
Inspection"Vehicle running–100 to 100 d/s
SIDE G-SENSOR Transverse G detected
by side G-sensorVehicle stopped
Approx. 0 m/s
2BRC-41, "Yaw Rate/Side/
Decel G Sensor System
Inspection"Vehicle running–16.7 to 16.7 m/s2
BATTERY VOLT Battery voltage sup-
plied to ABS actuator
and electric unit (con-
trol unit)Ignition switch ON
10 to 16VBRC-46, "
ABS/TCS/VDC
Control Unit Power and
Ground Systems Inspec-
tion"
STOP LAMP SW
Stop lamp switch oper-
ationBrake pedal depressed ON
BRC-45, "
Stop Lamp
Switch System Inspec-
tion"Brake pedal not depressed OFF
OFF SW VDC OFF switch
ON/OFF status VDC OFF switch ON
(When VDC OFF indicator
lamp is ON)
ON
BRC-56, "
VDC OFF
SWITCH"VDC OFF switch OFF
(When VDC OFF indicator
lamp is OFF) OFF
ABS WARN LAMP ABS warning lamp ON
condition (Note 2)ABS warning lamp ON ON
—
ABS warning lamp OFF OFF
MOTOR RELAY Operation status of
motor and motor relayIgnition switch ON or running
(ABS not activated)
OFF
BRC-44, "
Actuator Motor,
Motor Relay, and Circuit
Inspection"Ignition switch ON or engine
running (ABS activated) ON
ACTUATOR RLY Actuator relay opera-
tion statusVehicle stopped (Ignition
switch ON)
OFF
BRC-44, "
Actuator Motor,
Motor Relay, and Circuit
Inspection"Vehicle stopped (Engine run-
ning) ON
OFF LAMP VDC OFF indicator
lamp status (Note 3) When VDC OFF indicator
lamp is ON
ON
BRC-54, "
CAN Commu-
nication System Inspec-
tion"When VDC OFF indicator
lamp is OFF OFF
SLIP LAMP SLIP indicator lamp
status (Note 4)When SLIP indicator lamp is
ON
ON
BRC-54, "
CAN Commu-
nication System Inspec-
tion"When SLIP indicator lamp is
OFF OFF
Monitor item
Display content Data monitor
Note: Error inspection
checklist
Condition Reference value in
normal operation

BRC-26
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
Note 1: Confirm tire pressure is normal.
Note 2: ON/OFF timing of ABS warning lamp
ON: For approximately 2 seconds after ignition switch is turned ON, or when a malfunction is detected.
OFF: Approximately 2 seconds after ignition switch is turned ON (when system is in normal operation) and TCS/VDC function is not
activated.
Note 3: ON/OFF timing of VDC OFF indicator lamp
ON: For approximately 2 seconds after ignition switch is turned ON, or when a malfunction is detected and VDC OFF switch is ON.
OFF: Approximately 2 seconds after ignition switch is turned ON (when system is in normal operation.) And when VDC OFF switch is
OFF.
Note 4: SLIP indicator lamp ON/OFF timing
ON: For approximately 2 seconds after ignition switch is turned ON, or when a malfunction is detected and TCS/VDC function is act i-
vated while driving. FR LH IN SOL
FR LH OUT SOL
FR RH IN SOL
FR RH OUT SOL
RR RH IN SOL
RR RH OUT SOL
RR LH IN SOL
RR LH OUT SOL
Solenoid valve opera-
tionActuator (solenoid) is active
(
“ACTIVE TEST ” with CON-
SULT-II) or actuator relay is
inactive (in fail-safe mode). ON
BRC-43, "
Solenoid and
VDC Change-Over Valve
System Inspection"
When actuator (solenoid) is
not active and actuator relay is
active (ignition switch ON). OFF
CV1
CV2
SV1
SV2 VDC switch-over valve
statusWhen actuator (switch-over
valve) is active (
“ACTIVE
TEST ” with CONSULT-II) or
actuator relay is inactive (when
in fail-safe mode). ON
When actuator (switch-over
valve) is not active and actua-
tor relay is active (ignition
switch ON). OFF
DECEL G-SEN Longitudinal accelera-
tion detected by Decel
G-SensorVehicle stopped Approx. 0 G
BRC-41, "
Yaw Rate/Side/
Decel G Sensor System
Inspection"Vehicle running-1.7 to 1.7 G
PRESS SENSOR Brake fluid pressure
detected by pressure
sensorDo not step on the Brake pedal
(When ignition switch is ON)
Approx. 0 bar
—
Step on the Brake pedal
(When ignition switch is ON) -40 to 300 bar
FLUID LEV SW ON/OFF status of
brake fluid level switchWhen brake fluid level switch
ON
ON
DI-31, "
WARNING
LAMPS"When brake fluid level switch
OFF OFF
VDC SIGNAL
TCS SIGNAL
ABS SIGNAL
EBD SIGNAL Signal statusVDC active
TCS active
ABS active
EBD active
ON
VDC system
TCS system
ABS system
EBD system
VDC not active
TCS not active
ABS not active
EBD not active OFF
VDC FAIL SIG
TCS FAIL SIG
ABS FAIL SIG
EBD FAIL SIG Fail signal statusVDC fail
TCS fail
ABS fail
EBD fail
ON
VDC system
TCS system
ABS system
EBD system
VDC normal
TCS normal
ABS normal
EBD normal OFF
Monitor item
Display content Data monitor
Note: Error inspection
checklist
Condition Reference value in
normal operation

TROUBLE DIAGNOSISBRC-31
[VDC/TCS/ABS]
C
DE
G H
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K L
M A
B
BRC
Revision: November 2009 2006 QX56
FR LH IN ABS SOL
[C1120]Circuit of front LH IN ABS solenoid is open or shorted, or control
line is open or shorted to power supply or ground.
BRC-43, "
Solenoid and
VDC Change-Over Valve
System Inspection"
FR LH OUT ABS SOL
[C1121]Circuit of front LH OUT ABS solenoid is open or shorted, or con-
trol line is open or shorted to power supply or ground.
RR RH IN ABS SOL
[C1126] Circuit of rear RH IN ABS solenoid is open or shorted, or control
line is open or shorted to power supply or ground.
RR RH OUT ABS SOL
[C1127] Circuit of rear RH OUT ABS solenoid is open or shorted, or con-
trol line is open or shorted to power supply or ground.
FR RH IN ABS SOL
[C1122] Circuit of front RH IN ABS solenoid is open or shorted, or control
line is open or shorted to power supply or ground.
FR RH OUT ABS SOL
[C1123] Circuit of front RH OUT ABS solenoid is open or shorted, or con-
trol line is open or shorted to power supply or ground.
RR LH IN ABS SOL
[C1124] Circuit of rear LH IN ABS solenoid is open or shorted, or control
line is open or shorted to power supply or ground.
RR LH OUT ABS SOL
[C1125] Circuit of rear LH OUT ABS solenoid is open or shorted, or con-
trol line is open or shorted to power supply or ground.
CV1
[C1164] Front side VDC switch-over solenoid valve (cut valve) is open or
shorted, or control line is open or shorted to power supply or
ground.
CV2
[C1165] Rear side VDC switch-over solenoid valve (cut valve) is open or
shorted, or control line is open or shorted to power supply or
ground.
SV1
[C1166] Front side VDC switch-over solenoid valve (suction valve) is
open or shorted, or control line is open or shorted to power sup-
ply or ground.
SV2
[C1167] Rear side VDC switch-over solenoid valve (suction valve) is open
or shorted, or control line is open or shorted to power supply or
ground.
PUMP MOTOR
[ C 1111 ] During actuator motor operation with ON, when actuator motor
turns OFF or when control line for actuator motor relay is open.
BRC-44, "
Actuator
Motor, Motor Relay, and
Circuit Inspection"During actuator motor operation with OFF, when actuator motor
turns ON or when control line for relay is shorted to ground.
BATTERY VOLTAGE
[ABNORMAL]
[C1109] ABS actuator and electric unit (control unit) power voltage is too
low. BRC-46, "
ABS/TCS/
VDC Control Unit Power
and Ground Systems
Inspection"
ST ANG SEN SIGNAL
[C1144]
Neutral position correction of steering angle sensor is not fin-
ished. BRC-55, "Inspection For
Self-diagnosis Result
"ST ANG SEN SIGNAL""
ST ANG SEN COM CIR
[C1156]
CAN communication line or steering angle sensor has generated
an error. BRC-40, "Steering Angle
Sensor System"
G-SENSOR
[C1113]Longitudinal G-sensor is malfunctioning, or signal line of longitu-
dinal G-sensor is open or shorted. BRC-41, "Yaw Rate/
Side/Decel G Sensor
System Inspection"
CONTROLLER FAILURE
[C1110]
Internal malfunction of ABS actuator and electric unit (control
unit) BRC-40, "ABS/TCS/
VDC Control Unit
Inspection"
CAN COMM CIRCUIT
[U1000]

CAN communication line is open or shorted.

ABS actuator and electric unit (control unit) internal malfunc-
tion

Battery voltage for ECM is suddenly interrupted for approxi-
mately 0.5 second or more.BRC-54, "
CAN Commu-
nication System Inspec-
tion" (Note 2)
SIDE G-SEN CIRCUIT
[C1146] Lateral G-sensor is malfunctioning, or signal line of lateral G-sen-
sor is open or shorted. BRC-41, "
Yaw Rate/
Side/Decel G Sensor
System Inspection"
Self-diagnostic item
Malfunction detecting condition Check system

BRC-32
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
Note 1. If wheel sensor 2 for each wheel is indicated, check ABS actuator and electric unit (control unit) power
supply voltage in addition to wheel sensor circuit check.
Note 2. If multiple malfunctions are detected including CAN communication line [U1000], perform diagnosis for
CAN communication line first.
DATA MONITOR
Operation Procedure
1. After turning OFF the ignition switch, connect CONSULT-II and the CONSULT-II CONVERTER to the data
link connector.
CAUTION:
If CONSULT-II is used with no connection of CONSULT-II CONVERTER, malfunctions might be
detected in self-diagnosis depending on control unit which carries out CAN communication.
2. Touch “START (NISSAN BASED VHCL) ”, “ABS”, “DATA MONITOR ” in order on the CONSULT-II screen.
If “ABS” is not indicated, go to GI-40, "
CONSULT-II Data Link Connector (DLC) Circuit" .
BR FLUID LEVEL LOW
[C1155] Brake fluid level drops or circuit between ABS actuator and elec-
tric unit (control unit) and brake fluid level switch is open or
shorted. BRC-47, "Brake Fluid
Level Switch System
Inspection"
ENGINE SIGNAL 1
[C1130]
Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunction-
ing.
BRC-39, "
Engine Sys-
tem Inspection"
ENGINE SIGNAL 2
[C1131]Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunction-
ing.
ENGINE SIGNAL 3
[C1132] Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunction-
ing.
ENGINE SIGNAL 4
[C1133] Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunction-
ing.
ENGINE SIGNAL 6
[C1136] Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunction-
ing.
ACTUATOR RLY
[C1140] ABS actuator relay or circuit malfunction. BRC-44, "
Actuator
Motor, Motor Relay, and
Circuit Inspection"
PRESS SEN CIRCUIT
[C1142]
ABS pressure sensor circuit malfunction.
BRC-51, "Pressure Sen-
sor System Inspection"
VARIANT CODING
[C1170]V coding is not malfunctioning. BRC-40, "ABS/TCS/
VDC Control Unit
Inspection"
ABS ACTIVE BOOSTER SV NG
[C1178]Active booster solenoid is malfunctioning, or signal line of active
booster servo is open or shorted. BRC-48, "Active Booster
System Inspection"
ABS DELTA S SEN NG
[C1179]Delta stroke sensor malfunctioning, or signal line of delta stroke
sensor is open or shorted. BRC-49, "Delta Stroke
Sensor System Inspec-
tion"
ABS ACTIVE BOOSTER
RESPONSE NG
[C1181]Active booster response is malfunctioning, or signal line of active
booster response is open or shorted.
BRC-48, "Active Booster
System Inspection"
ABS BRAKE RELEASE SW NG
[C1184]Brake release switch is malfunctioning, or signal line of brake
release switch is open or shorted. BRC-48, "Active Booster
System Inspection"
ABS ACC CU INTERNAL NG
[C1185]
ICC control unit internal malfunction.
BRC-54, "ICC System
Inspection"
ABS BRAKE BOOSTER DEFECT
[C1189]Brake booster is defective or malfunctioning. BRC-48, "Active Booster
System Inspection"
Self-diagnostic item
Malfunction detecting condition Check system

BRC-34
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
RR RH IN SOL
(ON/OFF)–
×× Rear RH IN ABS solenoid (ON/
OFF) status is displayed.
RR RH OUT SOL
(ON/OFF) –
×× Rear RH OUT ABS solenoid (ON/
OFF) status is displayed.
FR RH IN SOL
(ON/OFF) –
×× Front RH IN ABS solenoid (ON/
OFF) status is displayed.
FR RH OUT SOL
(ON/OFF) –
×× Front RH OUT ABS solenoid (ON/
OFF) status is displayed.
RR LH IN SOL
(ON/OFF) –
×× Rear LH IN ABS solenoid (ON/
OFF) status is displayed.
RR LH OUT SOL
(ON/OFF) –
×× Rear LH OUT ABS solenoid (ON/
OFF) status is displayed.
OFF LAMP
(ON/OFF) –
×× OFF Lamp (ON/OFF) status is dis-
played.
MOTOR RELAY
(ON/OFF) –
×× ABS motor relay signal (ON/OFF)
status is displayed.
ACTUATOR RLY
(ON/OFF) –
×× ABS actuator relay signal (ON/
OFF) status is displayed.
CV1
(ON/OFF) ––
×Front side switch-over solenoid
valve (cut valve) (ON/OFF) status is
displayed.
CV2
(ON/OFF) ––
×Rear side switch-over solenoid
valve (cut-valve) (ON/OFF) status
is displayed.
SV1
(ON/OFF) ––
×Front side switch-over solenoid
valve (suction valve) (ON/OFF) sta-
tus is displayed.
SV2
(ON/OFF) ––
×Rear side switch-over solenoid
valve (suction valve) (ON/OFF) sta-
tus is displayed.
VDC FAIL SIG
(ON/OFF) ––
×VDC fail signal (ON/OFF) status is
displayed.
TCS FAIL SIG
(ON/OFF) ––
×TCS fail signal (ON/OFF) status is
displayed.
ABS FAIL SIG
(ON/OFF) ––
×ABS fail signal (ON/OFF) status is
displayed.
EBD FAIL SIG
(ON/OFF) ––
×EBD fail signal (ON/OFF) status is
displayed.
FLUID LEV SW
(ON/OFF) ×
– ×Brake fluid level switch (ON/OFF)
status is displayed.
EBD SIGNAL
(ON/OFF) ––
×EBD operation (ON/OFF) status is
displayed.
ABS SIGNAL
(ON/OFF) ––
×ABS operation (ON/OFF) status is
displayed.
TCS SIGNAL
(ON/OFF) ––
×TCS operation (ON/OFF) status is
displayed.
VDC SIGNAL
(ON/OFF) ––
×VDC operation (ON/OFF) status is
displayed.
EBD WARN LAMP ––×Brake warning lamp (ON/OFF) sta-
tus is displayed.
SLCT LVR POSI ××× Shift position judged by PNP switch
signal.
Item
(Unit) Data monitor item selection
Remarks
ECU INPUT
SIGNALS MAIN
SIGNALS SELECTION
FROM MENU

TROUBLE DIAGNOSISBRC-35
[VDC/TCS/ABS]
C
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G H
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K L
M A
B
BRC
Revision: November 2009 2006 QX56
×: Applicable
– : Not applicable
ACTIVE TEST
CAUTION:

Do not perform active test while driving.

Make sure to completely bleed air from the brake system.

The ABS and brake (EBD) warning lamps turn on during the active test.
R POSI SIG ––× Shift position judged by PNP switch
signal.
4WD FAIL REQ ––× The state of 4WD controller is dis-
played by CAN communication sig-
nal.
2WD/4WD ––× It recognizes on software whether it
is 2WD and whether it is in 4WD
state.
BST OPER SIG ––× Active booster operation (ON/OFF)
status is displayed.
PRESS SENSOR ×–×Brake pressure detected by pres-
sure sensor is displayed.
CRANKING SIG ––× The input state of the key SW
START position signal is displayed.
PRESS SEN 2 ––× Brake pressure detected by pres-
sure sensor is displayed.
DELTA S SEN ––× The amount of stroke sensor move-
ments in the active booster
detected by DELTA S SEN is dis-
played.
RELEASE SW NO ––× Release switch signal (ON/OFF)
status is displayed. "ON" indicates
that the brake pedal is depressed.
"OFF" is that the brake pedal is
released.
RELEASE SW NC ––× Release switch signal (ON/OFF)
status is displayed. "OFF" indi-
cates that the brake pedal is
depressed on. "ON" is that the
brake pedal is released.
OHB FAIL ––× OHB fail status is displayed.
HBA FAIL ––× HBA fail status is displayed.
OHB SIG ––× OHB operation (ON/OFF) status is
displayed.
HBA SIG ––× HBA operation (ON/OFF) status is
displayed.
PRES CTRL ACC ––× Pressure control state (ON/OFF) is
displayed. It is applied only to an
ICC vehicle.
PRES FAIL ACC ––× Pressure control fail state (ON/
OFF) is displayed. It is applied only
to an ICC vehicle.
STP OFF RLY ––× Stop lamp relay signal (ON/OFF)
status is displayed.
Item
(Unit) Data monitor item selection
Remarks
ECU INPUT
SIGNALS MAIN
SIGNALS SELECTION
FROM MENU

TROUBLE DIAGNOSISBRC-37
[VDC/TCS/ABS]
C
DE
G H
I
J
K L
M A
B
BRC
Revision: November 2009 2006 QX56
ABS Motor
Touch “ON” and “OFF ” on the screen. Check that ABS motor relay
operates as shown in table below.
NOTE:

If active test is performed with brake pedal depressed, pedal
stroke may change. This is normal.

“TEST IS STOPPED ” is displayed approximately 10 seconds
after operation starts.
Booster Drive
CAUTION:
Perform active test subject to the conditions below.

Do not operate brake pedal during active test.

Make sure the engine revolution is over 500 rpm.

Make sure the vehicle is not moving.
Touch "UP" and "DOWN" on the screen. Check that booster drive
operates as shown in table below.
NOTE:
"TEST IS STOPPED" is displayed approximately 10 seconds after operation starts.
Operation ONOFF
ABS actuator relay ONON
ABS motor relay ONOFF
SFIA0593E
Operation UPDOWN
STOP LAMP SW ONOFF
BST OPER SIG ONOFF
PRESS SENSOR 50 ± 5 bar 0 bar
PRESS SEN 2 50 ± 5 bar 0 bar
STP OFF RLY OFFOFF
WFIA0350E