air filter SUZUKI SWIFT 2005 2.G Service User Guide

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-37
TP SENSOR 2 VOLT (THROTTLE POSITION SENSOR
(SUB) OUTPUT VOLTAGE, V)
The TP sensor (sub) reading provides throttle valve
opening information in the form of voltage.
APP SENSOR 1 VOLT (ACCELERATOR PEDAL
POSITION (APP) SENSOR (MAIN) OUTPUT
VOLTAGE, V)
The APP sensor (main) read ing provides accelerator
pedal opening information in the form of voltage.
APP SENSOR 2 VOLT (ACCELERATOR PEDAL
POSITION (APP) SENSOR (S UB) OUTPUT VOLTAGE,
V)
The APP sensor (sub) reading provides accelerator
pedal opening information in the form of voltage.
ACCEL POSITION (ABSOLUTE ACCELERATOR
PEDAL POSITION, %)
When accelerator pedal is at fully released position,
accelerator pedal is indicated as 0 – 5% and 90 – 100%
fully depressed position. THROTTLE TARGET POSI (TARGET THROTTLE
VALVE POSITION, %)
Target throttle valve position is ECM internal parameter
which indicates the ECM requested throttle valve
position.
BATTERY CURRENT (A)
This parameter indicates elec
tric load value (current
consumption) that detected by electric load current
sensor.
GENERATOR CONT DUTY (GENERATOR CONTROL
DUTY, %)
This parameter indicates generator control duty ratio that
controls production electricity of generator by ECM.
100%: No limitation for the generating
0%: Maximum limitation for the generating
GENERATOR FIELD DUTY (GENERATOR FIELD
COIL DUTY, %)
This parameter indicates ope rating rate (status of
production electricity) for gen erator by field coil duty
ratio.
100%: maximum operation.
0%: minimum operation.
Visual InspectionS7RS0B1104008
Visually check the following parts and systems.
Inspection item Reference section
• Engine oil – level, leakage “Engine Oil and Filter Change in Section 0B”
• Engine coolant – level, leakage “Co olant Level Check in Section 1F”
• Fuel – level, leakage “Fuel Lines and Connections Inspection in Section 0B”
• Air cleaner element – dirt, clogging “Air Cleaner Filter Inspection in Section 0B”
• Battery – fluid level, corrosion of terminal “Battery Description in Section 1J”
• Water pump belt – tension damage “Accessory Drive Belt Inspection in Section 0B”
• Throttle valve – operating sound “Electric Throttle Body Assembly On-Vehicle Inspection in Section 1C”
• Vacuum hoses of air intake system – disconnection, looseness,
deterioration, bend “Vacuum Hose and Purge Valve Chamber
Inspection in Section 1B”
• Connectors of electric wire harness – disconnection, friction
• Fuses – burning
• Parts – installation, bolt – looseness
• Parts – deformation
• Other parts that can be checked visually
Also check the following items at engine start, if possible
• Malfunction indicator lamp – Operation “Malfunction Indicator Lamp (MIL) Check”
• Charge warning lamp – Operation “Genera tor Symptom Diagnosis in Section 1J”
• Engine oil pressure warning lamp – Operation “O il Pressure Switch Inspection in Section 9C”
• Engine coolant temp. meter – Operation “ECT Sensor Inspection in Section 1C”
• Fuel level meter – Operation “Fuel Level Sensor Inspection in Section 9C”
• Tachometer – Operation
• Abnormal air being inhaled from air intake system
• Exhaust system – leakage of exhaust gas, noise
• Other parts that can be checked visually

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-41
Engine Symptom DiagnosisS7RS0B1104010
Perform troubleshooting referring to the followings when ECM has detected no DTC and no abnormality has been
found in “Visual Inspection” and “Engine Basic Inspection”.
Condition Possible cause Correction / Reference Item
Hard starting (Engine
cranks OK) Faulty spark plug
“Spark Plug Inspection in Section 1H”
Leaky high-tension cord “High-Tension Cord Inspection in Section 1H”
Loose connection or disconnection of
high-tension cord(s) or lead wire(s) “High-Tension Cord Removal and Installation
in Section 1H”
Faulty ignition coil “Ignition Coil Assembly (Including ignitor)
Inspection in Section 1H”
Dirty or clogged fuel hose or pipe “Fuel Pressure Check”
Malfunctioning fuel pump “Fuel Pressure Check”
Air drawn in through intake manifold
gasket or throttle body gasket
Faulty electric throttle body assembly “Electric Throttle Body Assembly On-Vehicle
Inspection in Section 1C”
Faulty APP sensor assembly “APP Sensor Assembly Inspection in Section
1C”
Faulty ECT sensor or MAF sensor “ECT Sensor Inspection in Section 1C” or
“MAF and IAT Sensor Inspection in Section
1C”
Faulty ECM
Low compression “Compression Check in Section 1D”
Poor spark plug tightening or faulty
gasket “Spark Plug Removal and Installation in
Section 1H”
Compression leak from valve seat “Valves and Valve Guides Inspection in
Section 1D”
Sticky valve stem “Valves and Valve Guides Inspection in
Section 1D”
Weak or damaged valve springs “Valve Spring Inspection in Section 1D”
Compression leak at cylinder head
gasket “Cylinder Head Inspection in Section 1D”
Sticking or damaged piston ring “Cylinders, Pistons and Piston Rings
Inspection in Section 1D”
Worn piston, ring or cylinder “Cylinders, Pistons and Piston Rings
Inspection in Section 1D”
Malfunctioning PCV valve “PCV Valve Inspection in Section 1B”
Camshaft position control (VVT) system
out of order “Oil Control Valve Inspection in Section 1D”
Faulty EGR system “EGR System Inspection in Section 1B”
Low oil pressure Improper oil viscosity “Engine Oil and Filter Change in Section 0B”
Malfunctioning oil pressure switch “Oil Pressure Switch Inspection in Section 9C”
Clogged oil strainer “Oil Pan and Oil Pump Strainer Cleaning in
Section 1E”
Functional deterioration of oil pump “Oil Pump Inspection in Section 1E”
Worn oil pump relief valve “Oil Pump Inspection in Section 1E”
Excessive clearance in various sliding
parts
Engine noise – Valve
noise
NOTE
Before checking
mechanical noise, make
sure that:
• Specified spark plug is used.
• Specified fuel is used.

Improper valve lash “Camshaft, Tappet and Shim Inspection in
Section 1D”
Worn valve stem and guide “Valves and Valve Guides Inspection in
Section 1D”
Weak or broken valve spring “Valve Spring Inspection in Section 1D”
Warped or bent valve “Valves and Valve Guides Inspection in
Section 1D”

Downloaded from www.Manualslib.com manuals search engine 1A-42 Engine General Information and Diagnosis:
Engine noise – Piston,
ring and cylinder noise
NOTE
Before checking
mechanical noise, make
sure that:
• Specified spark plug is used.
• Specified fuel is used.

Worn piston, ring and cylinder bore “Cylinders, Pistons and Piston Rings
Inspection in Section 1D”
Engine noise –
Connecting rod noise
NOTE
Before checking
mechanical noise, make
sure that:
• Specified spark plug is used.
• Specified fuel is used.

Worn piston, ring and cylinder bore “Cylinders, Pistons and Piston Rings
Inspection in Section 1D”
Worn rod bearing “Crank Pin and Connecting Rod Bearings
Inspection in Section 1D”
Worn crank pin “Crank Pin and Connecting Rod Bearings
Inspection in Section 1D”
Loose connecting rod nuts “Pistons, Piston Rings, Connecting Rods and
Cylinders Removal and Installation in Section
1D”
Low oil pressure Condition “Low oil pressure”
Engine noise –
Crankshaft noise
NOTE
Before checking
mechanical noise, make
sure that:
• Specified spark plug is used.
• Specified fuel is used.

Low oil pressure Condition “Low oil pressure”
Worn bearing “Main Bearings Inspection in Section 1D”
Worn crankshaft journal “Crankshaft Inspection in Section 1D”
Loose bearing cap bolts “Main Bearings, Crankshaft and Cylinder Block
Removal and Installation in Section 1D”
Excessive crankshaft thrust play “Crankshaft Inspection in Section 1D”
Engine overheating Inoperative thermostat “Thermostat Inspection in Section 1F”
Poor water pump performance “Water Pump Inspection in Section 1F”
Clogged or leaky radiator “Radiator On-Vehicle Inspection and Cleaning
in Section 1F”
Improper engine oil grade “Engine Oil and Filter Change in Section 0B”
Clogged oil filter or oil strainer “Oil Pressure Check in Section 1E”
Poor oil pump performance “Oil Pressure Check in Section 1E”
Faulty radiator cooling fan control
system “Radiator Cooling Fan Low Speed Control
System Check” or “Rad
iator Cooling Fan High
Speed Control System Check”
Dragging brakes Condition “Dragging brakes” in “Brakes
Symptom Diagnosis in Section 4A”
Slipping clutch Condition “Slipping clutch” in “Clutch System
Symptom Diagnosis in Section 5C”
Blown cylinder head gasket “Cylinder Head Inspection in Section 1D”
Air mixed in cooling system
Condition Possible cause Correction / Reference Item

Downloaded from www.Manualslib.com manuals search engine 1A-44 Engine General Information and Diagnosis:
Engine hesitates –
Momentary lack of
response as accelerator
is depressed. Can occur
at all vehicle speeds.
Usually most severe when
first trying to make
vehicle move, as from a
stop sign.Spark plug faulty
“Spark Plug Inspection in Section 1H”
Leaky high-tension cord “High-Tension Cord Inspection in Section 1H”
Fuel pressure out of specification “Fuel Pressure Check”
Malfunctioning EGR valve “EGR Valve Inspection in Section 1B”
Poor performance of ECT sensor or
MAF sensor “ECT Sensor Inspection in Section 1C” or
“MAF and IAT Sensor Inspection in Section
1C”
Faulty electric throttle body assembly “Electric Throttle Body Assembly On-Vehicle
Inspection in Section 1C”
Faulty APP sensor assembly “APP Sensor Assembly Inspection in Section
1C”
Faulty fuel injector “Fuel Injector Circuit Check”
Faulty ECM
Engine overheating Condition “Engine overheating”
Low compression “Compression Check in Section 1D”
Camshaft position control (VVT) system
out of order “Oil Control Valve Inspection in Section 1D”
Surge – Engine power
variation under steady
throttle or cruise. Feels
like vehicle speeds up
and down with no change
in accelerator pedal. Leaky or loosely connected high-tension
cord
“High-Tension Cord Removal and Installation
in Section 1H”
Faulty spark plug (excess carbon
deposits, improper gap, burned
electrodes, etc.) “Spark Plug Inspection in Section 1H”
Variable fuel pressure “Fuel Pressure Check”
Kinky or damaged fuel hose and lines
Faulty fuel pump (clogged fuel filter)
Malfunctioning EGR valve “EGR Valve Inspection in Section 1B”
Poor performance of MAF sensor “MAF and IAT Sensor Inspection in Section
1C”
Faulty fuel injector “Fuel Injector Circuit Check”
Faulty electric throttle body assembly “Electric Throttle Body Assembly On-Vehicle
Inspection in Section 1C”
Faulty APP sensor assembly “APP Sensor Assembly Inspection in Section
1C”
Faulty ECM
Excessive detonation –
Engine makes
continuously sharp
metallic knocks that
change with throttle
opening. Sounds like pop
corn popping. Faulty spark plug
“Spark Plug Inspection in Section 1H”
Loose connection of high-tension cord “High-Tension Cord Removal and Installation
in Section 1H”
Engine overheating Condition “Engine overheating”
Clogged fuel filter (faulty fuel pump) or
fuel lines “Fuel Pressure Check” or “Fuel Pump and Its
Circuit Check”
Air drawn in through intake manifold or
throttle body gasket
Malfunctioning EGR valve “EGR Valve Inspection in Section 1B”
Poor performance of knock sensor, ECT
sensor or MAF sensor “DTC P0327 / P0328: Knock Sensor 1 Circuit
Low / High”, “ECT Sensor Inspection in
Section 1C” or “MAF and IAT Sensor
Inspection in Section 1C”
Faulty fuel injector(s) “Fuel Injector Circuit Check”
Faulty ECM
Excessive combustion chamber
deposits “Cylinders, Pistons and Piston Rings
Inspection in Section 1D” and/or “Piston Pins
and Connecting Rods In
spection in Section
1D”
Camshaft position control (VVT) system
out of order “Oil Control Valve Inspection in Section 1D”
Condition Possible cause Correction / Reference Item

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-49
Troubleshooting
NOTE
When measuring circuit voltage, resistance and/or pulse signal at ECM connector, connect the special
tool to ECM and/or the ECM connectors referri ng to “Inspection of ECM and Its Circuits”.

DTC P0010: “A” Camshaft Position Actuator CircuitS7RS0B1104013
System and Wiring DiagramStep Action Yes No
1 DTC check
1) Start engine and recheck DTC of ECM and TCM (for A/T
model) while engine running.
Is there any DTC(s)? Go to Step 2 of “Engine
and Emission Control
System Check”, Step 2
of “A/T System Check in
Section 5A”.Go to Step 2.
2 CAN communication line circuit check
1) Check CAN communication line circuit between
combination meter and ECM, TCM (for A/T model)
referring to Step 3 of “DTC P1674: CAN Communication
(Bus Off Error)”.
Is circuit in good condition? Substitute a known-
good combination meter
and recheck. If MIL still
remains OFF, substitute
a known-good ECM and
recheck.
Repair or replace CAN
communication circuit.
3
7
1[A]: 45
6
C37-58
C37-15
C37-30
E23-31BLK
BLK
BLK/ORN
RED
YEL
YEL/RED
YEL/GRN
C37-60
C37-59
3 2
1
E23 C37
34
1819
567
1011
17
20
47 46
495051
2122
52 16
25 9
24
14
29
55
57 54 53
59
60 58 2
262728
15
30
56 4832 31
34353637
40
42 39 38
44
45 43 41 331
1213
238
34
1819
567
1011
17
20
47 46
495051
2122
52 16
25 9
24
14
29
55
57 54 53
59
60 58 2
262728
15
30
56 4832 31
34353637
40
42 39 38
44
45 43 41 331
1213
238
BLK
I6RS0C110013-01
[A]: Oil flow
2. ECM4. Oil filter6. Oil pan
1. Oil control valve 3. Camshaft timing sprocket5. Oil pump7. Intake camshaft

Downloaded from www.Manualslib.com manuals search engine 1A-204 Engine General Information and Diagnosis:
Troubleshooting
NOTE
Before using following flow, check to make sure that battery voltage is higher than 11 V. If battery
voltage is low, pressure becomes lower than specification even if fuel pump and line are in good
condition.

StepAction YesNo
1 Fuel pressure check
1) Check fuel pressure referring to “Fuel Pressure
Inspection in Section 1G”.
Is check result satisfactory? Go to Step 2.
Go to Step 5.
2 Fuel pressure check
1) Start engine and warm it up to normal operating
temperature.
2) Keep engine speed at 4000 rpm.
Does fuel pressure show about the same value as Step 1? Go to Step 3.
Go to Step 8.
3 Fuel line check
1) Check fuel pipe, fuel hose and joint for fuel leakage.
Are they in good condition? Go to Step 4.
Repair or replace
defective part.
4 Fuel line check
1) Check fuel pipe, fuel hose and joint for damage or
deform.
Are they in good condition? Faulty fuel pressure
regulator.
Repair or replace
damaged or damaged
part.
5 Was fuel pressure higher than specification in Step 1? Go to Step 6.Go to Step 7.
6 Fuel line check
1) Check fuel pipe, fuel hose and joint for damage or
deform.
Are they in good condition? Faulty fuel pressure
regulator.
Repair or replace
damaged or damaged
part.
7 Fuel pump operating sound check
1) Remove fuel filler cap and th en turn ON ignition switch.
Can you hear operating sound? Go to Step 8.
Faulty fuel pump.
8 Fuel line check
1) Check fuel pipe, fuel hose and joint for damage or
deform.
Are they in good condition? Clogged fuel filter, faulty
fuel pump, faulty fuel
pressure regulator or
fuel leakage from hose
connection in fuel tank.Repair or replace
defective part.

Downloaded from www.Manualslib.com manuals search engine Engine Mechanical: 1D-2
Camshaft Position Control (VVT Variable Valve Timing) System DescriptionS7RS0B1401002
System Description
The VVT system is an electronic control system which continuously vary and optimize the intake valve timing in
response to the engine operating condition.
The optimized intake valve timing produce such an air intake with high efficiency that both the higher power generation
and lower fuel consumption can be attained in the whole engine speed range from low to high. In the area of the
average engine load, low emission of nitrogen oxides (NOx) and high fuel efficiency can also be attained by making
the valve opening overlap between the intake and exhaust valves longer.
For the brief of the system operation, the intake valve timing is varied by the cam timing sprocket (1) which varies the
rotational phase between the intake camshaft (3) and sprocket . The rotor (2) in the cam timing sprocket is actuated by
switching or adjusting the hydraulic pressure applied to the chambers for the timing advancing (7) and/or retarding (6).
To switch or adjust the hydraulic pressure appropriately, ECM operates the oil control valve (12) with detecting the
engine speed, intake air value, throttle opening, engine coolant temperature and camshaft position (angle).
1
4
5
13
10
89
2
7
6
12
11
3
14
60 (variable angle)
Most retarded timing
Most advanced timing
Exhaust valve Intake valve
Crank angle
Overlap of valves
Valve lift
I3RH0B140002-01
4. Oil passage to chamber for timing retarding 8. Oil filter10. Oil pan 13. Oil return
5. Oil passage to chamber for timing advancing 9. Oil pump11. Control signal from ECM 14. Oil flow

Downloaded from www.Manualslib.com manuals search engine 1E-2 Engine Lubrication System:
Diagnostic Information and Procedures
Oil Pressure CheckS7RS0B1504001
WARNING!
To avoid danger of being burned, do not
touch exhaust system when it is still hot.

NOTE
Prior to checking oil pressure, check the
following.
• Oil level in oil pan
If oil level is low, add oil up to Full level
mark (hole) (1) on oil level gauge referring
to “Engine Oil and Filter Change in Section
0B”.
• Oil quality If oil is discolored or deteriorated, change
it. For particular oil to be used, refer to
“Engine Oil and Filter Change in Section
0B”.
• Oil leaks If leak is found, repair it.

1) Remove front bumper referring to “Front Bumper and Rear Bumper Components in Section 9K”.
2) Remove engine front cover (1).
3) Disconnect oil pressure switch coupler (1).
4) Remove oil pressure swit ch (2) from cylinder block.
5) Install special tools (oil pressure gauge) to vacated threaded hole of oil pressure switch.
Special tool
(A): 09915–77310
(B): 09915–78211
2. Low level mark (hole)
I2RH0B150002-01
1
I4RS0A150001-01
I2RH0B150003-01
I2RH0B150004-01

Downloaded from www.Manualslib.com manuals search engine Engine Lubrication System: 1E-3
6) Start engine and warm engine up to normal operating temperature.
NOTE
Be sure to shift transaxle gear shift lever in
“Neutral” (shift select lever in “P” range for
A/T vehicle), set parking brake and block
drive wheels.

7) After warming up, raise engine speed to 4,000 r/min. and measure oil pressure.
Oil pressure specification
More than 270 kPa (2.7 kg/cm2, 39.8 psi) at 4,000
r/min. (rpm)
8) After checking oil pressure, stop engine and remove oil pressure gauge and attachment.
9) Before reinstalling oil pressure switch (2), be sure to
wrap its screw threads with sealing tape (1) and
tighten switch to specified torque.
NOTE
If sealing tape edge is bulged out from screw
threads of switch, cut it off.

Tightening torque
Oil pressure switch (a): 13 N·m (1.3 kgf-m, 9.5
lb-ft) 10) Start engine and check oil pressure switch for oil
leakage. If oil leakage is found, repair it.
11) Connect oil pressure switch coupler (1).
Repair Instructions
Heat Exchanger ComponentsS7RS0B1506001
I2RH0B150005-01
I2RH0B150006-01
3
4
5
7
6
(a)
2
1
I6RS0B151001-02
1. Heat exchanger inlet No. 1 hose 4. Gasket7. O-ring
: Apply engine oil.
2. Heat exchanger outlet No. 1 hose 5. Heat exchanger stand bolt : 22 N⋅m (2.2 kgf-m, 16.0 lb-ft)
3. Heat exchanger 6. Oil filter adapter case : Do not reuse.

Downloaded from www.Manualslib.com manuals search engine Table of Contents 7- i
7
Section 7
CONTENTS
HVAC
Precautions ................................................. 7-1
Precautions............................................................. 7-1
Precautions on HVAC ........................................... 7-1
Heater and Ventilation.... ......................... 7A-1
General Description ............................................. 7A-1
Heater and Ventilation Construction ................... 7A-1
Schematic and Routing Diagram ........................ 7A-2 Heater and Ventilation Wiring Circuit Diagram .... 7A-2
Diagnostic Information and Procedures ............ 7A-3 Heater and Ventilation Symptom Diagnosis........ 7A-3
Repair Instructions .............................................. 7A-4 HVAC Unit Components ..................................... 7A-4
HVAC Unit Removal and Installation .................. 7A-4
Blower Motor Removal and Installation............... 7A-4
Blower Motor Inspection ..................................... 7A-4
Blower Motor Resistor Removal and Installation ......................................................... 7A-5
Blower Motor Resistor Inspection ....................... 7A-5
Blower Motor Relay Inspection ........................... 7A-6
HVAC Control Unit Components ......................... 7A-6
HVAC Control Unit Remova l and Installation ...... 7A-7
Blower Speed Selector In spection ...................... 7A-9
Air Intake Selector Inspec tion ............................. 7A-9
Air Intake Control Actuator Removal and Installation ......................................................... 7A-9
Air Intake Control Actuator Inspection .............. 7A-10
Center Ventilation Louver Removal and Installation ....................................................... 7A-10
Side Ventilation Louver Removal and Installation ....................................................... 7A-11
HVAC Air Filter Removal and Installation (If Equipped)........................................................ 7A-12
HVAC Air Filter Inspection (If Equipped) ........... 7A-12
Air Conditioning System... ...................... 7B-1
Manual Type ............................................................ 7B-1
Precautions........................................................... 7B-1A/C System Caution ............................................ 7B-1
Precautions on Servicing A/C System ................ 7B-1
General Description ............................................. 7B-3 Refrigerant Type Identifica tion ............................ 7B-3
Sub-Cool A/C System Description ...................... 7B-4
A/C Operation Description .................................. 7B-4 Schematic and Routing Diagram ........................7B-5
Major Components of A/C System ...................... 7B-5
A/C System Wiring Diagram ............................... 7B-6
Diagnostic Information and Procedures ............7B-7 A/C System Symptom Diagnosis ........................ 7B-7
Abnormal Noise Sympto m Diagnosis of A/C
System .............................................................. 7B-9
A/C System Performance Inspection ................ 7B-10
A/C System Inspection at ECM ......................... 7B-15
Repair Instructions ........... .................................7B-16
Operation Procedure for Re frigerant Charge .... 7B-16
Condenser Assembly On-Vehicle Inspection .... 7B-21
Condenser Assembly Removal and Installation ....................................................... 7B-21
Receiver/Dryer Removal and Installation .......... 7B-22
HVAC Unit Components ................................... 7B-23
HVAC Unit Removal and In stallation ................ 7B-24
Evaporator Inspection ....................................... 7B-24
Evaporator Thermistor (Evaporator Temperature Sensor) Removal and
Installation ....................................................... 7B-25
Evaporator Thermistor (Evaporator Temperature Sensor) Inspec tion..................... 7B-25
Expansion Valve Removal and Installation ....... 7B-26
Expansion Valve Inspection .............................. 7B-26
A/C Refrigerant Pressure Sensor and Its Circuit Inspection............................................. 7B-26
A/C Refrigerant Pressu re Sensor Removal
and Installation ................................................ 7B-26
A/C Switch Inspection ....................................... 7B-27
Compressor Relay Inspection ........................... 7B-27
Compressor Drive Belt Inspection and Adjustment ...................................................... 7B-27
Compressor Drive Belt Removal and Installation ....................................................... 7B-28
Compressor Assembly Removal and Installation ....................................................... 7B-28
Compressor Assembly Components................. 7B-29
Magnet Clutch Inspection.................................. 7B-29
Magnet Clutch Removal and Installation........... 7B-29
Relief Valve Inspection...................................... 7B-31
Relief Valve Removal and Installation............... 7B-32
Specifications .................... .................................7B-32
Tightening Torque Specifications ...................... 7B-32
Special Tools and Equipmen t ...........................7B-33