Pressure SUZUKI SWIFT 2005 2.G Service Workshop Manual
[x] Cancel search | Manufacturer: SUZUKI, Model Year: 2005, Model line: SWIFT, Model: SUZUKI SWIFT 2005 2.GPages: 1496, PDF Size: 34.44 MB
Page 870 of 1496

Downloaded from www.Manualslib.com manuals search engine 6A-1 Steering General Diagnosis:
Steeri ng
Steering General Diagnosis
Precautions
Precautions for Steering DiagnosisS7RS0B6100001
Since the problems in steering involve several systems, they must all be considered when diagnosing a complaint. To
avoid using the wrong symptom, always road test the vehicl e first. Proceed with the following preliminary inspection
and correct any defects which are found.
1) Inspect tires for proper pressure and uneven wear.
2) Raise vehicle on a hoist and inspect steering system for loose or damaged parts.
3) Spin front wheels. Inspect for out-of-round tires, out- of-balance tires, bent rims, loosen and/or rough wheel
bearings.
Page 871 of 1496

Downloaded from www.Manualslib.com manuals search engine Steering General Diagnosis: 6A-2
Diagnostic Information and Procedures
Steering Symptom DiagnosisS7RS0B6104001
ConditionPossible cause Correction / Reference Item
Hard steering Tire not adequately inflated Inflate tires to proper pressure.
Malfunction of power steering system Check and correct.
Bind in tie-rod end ball studs or lower
ball joints Replace tie-rod end or front suspension arm.
Disturbed front wheel alignment Check and adjust front wheel alignment.
Bind in steering column Repair or replace steering column.
Rack and pinion adjustment Check and adjustment rack and pinion torque.
Too much play in steering Wheel bearings worn Replace wheel bearing.
Loose steering gear case bolts Tighten gear case bolts.
Faulty steering gear case assembly Replace steering gear case assembly.
Worn steering shaft joints Replace joint.
Worn tie-rod ends or tie-rod inside ball
joints Replace tie-rod end or tie-rod.
Worn lower ball joints Replace front suspension control arm.
Rack and pinion adjustment Check and adjustment rack and pinion torque.
Poor return ability Bind in tie-rod end ball studs Replace tie-rod end.
Bind in ball joints Replace front suspension control arm.
Bind in steering column Repair or replace steering column.
Disturbed front end alignment Check and adjust front end alignment.
Faulty steering gear case assembly Replace steering gear case assembly.
Tires not adequately inflated Adjust tire pressure.
Rack and pinion adjustment Check and adjustment rack and pinion torque.
Rack and pinion noise
(Rattle or chuckle) Loose steering gear case bolts
Tighten steering gear case bolts.
Rack and pinion adjustment Check and adjustment rack and pinion torque.
Faulty steering gear case assembly Replace steering gear case assembly.
Broken or other wise damaged wheel
bearing(s) Replace wheel bearing(s).
Wander or poor steering
stability Mismatched or uneven tires
Replace or inflate tires to proper pressure.
Loosen ball joints and tie-rod ends Replace suspension control arm or tie-rod end.
Faulty struts or mountings Replace strut or repair mounting.
Loose stabilizer bar Tighten or replace stabilizer bar or bush.
Broken or sagging springs Replace spring.
Rack and pinion adjustment Check and adjustment rack and pinion torque.
Disturbed front wheel alignment Check and adjust front wheel alignment.
Faulty steering gear case assembly Replace steering gear case assembly.
Erratic steering when
braking Worn wheel bearing(s)
Replace wheel bearing(s).
Broken or sagging spring(s) Replace coil spring(s).
Wheel tires are inflated unequally Inflate tires to proper pressure.
Disturbed front wheel alignment Check and adjust front wheel alignment.
Brakes not working in unison Check and repair brake system.
Leaking caliper Repair or replace caliper.
Warped discs Replace brake disc.
Badly worn brake pads Replace brake pads.
Page 921 of 1496

Downloaded from www.Manualslib.com manuals search engine Power Assisted Steering System: 6C-39
Reference waveform No.3
Motor output signal 1(1), Motor output signal 2(2), with
engine idling
Steering Wheel Play CheckS7RS0B6304024
• Check steering wheel for looseness or rattle by moving it in its shaft direction and lateral direction.
If found defective, repair or replace.
• Check steering wheel for play, holding vehicle in straight forward condition on the ground with engine
stopped.
If steering wheel play is not within specification,
inspect as follows and replace if found defective.
• Tie-rod end ball stud for wear (Ball stud should move when more than 0.2 N ⋅m (2 kg-cm, 0.44 lb-ft) torque is
applied.)
• Lower ball joint for wear
• Steering shaft joint for wear • Steering pinion or rack gear for wear or breakage
• Each part for looseness
Steering wheel play
“a”
: 0 – 30 mm (0 – 1.18 in.)
Steering Force CheckS7RS0B6304025
1) Place vehicle on level road and set steering wheel at
straight-ahead position.
2) Check if tire inflation pressure is as specified referring to the tire placard.
3) Remove driver air bag (inflator) module referring to “Driver Air Bag (Inflator) Module Removal and
Installation in Section 8B”.
4) Start engine.
5) With engine idling, measure steering force by turning torque wrench.
Steering force
: Less than 6.4 N ⋅m (0.64 kgf-m, 4.6 lb-ft)
6) Install driver air bag (inflator) module referring to “Driver Air Bag (Inflator) Module Removal and
Installation in Section 8B”.
Measurement
terminal
CH1: “E51-1” to vehicle body ground
CH2: “E51-2” to vehicle body ground
Oscilloscope
setting CH1: 5 V/DIV, CH2: 5 V/DIV
TIME: 20
µs/DIV
Measurement
condition • Engine is idling and steering wheel
is kept fully turned to left or right
until it stops
[A]: Steering wheel is kept fully turned left until it stops
[B]: Steering wheel is kept fully turned right until it stops
[C]: 12 V ON
[D]: GND ON
I6RS0B630019-01
I3RM0A630021-01
I3RM0A630022-01
Page 933 of 1496

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
Page 934 of 1496

Downloaded from www.Manualslib.com manuals search engine 7-ii Table of Contents
Recommended Service Material ....................... 7B-33
Special Tool ...................................................... 7B-33
Automatic Type .................... .................................7B-34
Precautions.........................................................7B-34 A/C System Caution .......................................... 7B-34
Precautions in Diagnosing Trouble ................... 7B-34
Precautions on Servicing A/C System .............. 7B-34
General Description .......... .................................7B-34
Auto A/C System Descript ion ............................ 7B-34
HVAC Control Module Operation Description ... 7B-36
Refrigerant Type Identifica tion .......................... 7B-36
Sub-Cool A/C System Description .................... 7B-36
A/C Operation Description ................................ 7B-36
On-Board Diagnostic System Description ......... 7B-37
Schematic and Routing Diagram ......................7B-37 Major Components of A/C System .................... 7B-37
A/C System Wiring Diagra m ............................. 7B-38
Diagnostic Information and Procedures ..........7B-39 A/C System Symptom Diagnosis ...................... 7B-39
Abnormal Noise Sympto m Diagnosis of A/C
System ............................................................ 7B-42
DTC Check........................................................ 7B-42
DTC Clearance ................................................. 7B-43
DTC Table ......................................................... 7B-44
Fail-Safe Table ................. ................................. 7B-45
Scan Tool Data ................................................. 7B-46
Air Conditioning System Check......................... 7B-47
Visual Inspection ............................................... 7B-49
DTC B1502: Inside Air Temperature Sensor and/or Its Circuit Malfunction .......................... 7B-49
DTC B1503: A/C Evaporator Air Temperature Sensor and/or Its Circuit Malfunction .............. 7B-50
DTC B1504: Sunload Sensor and/or Its Circuit Malfunction ......... ................................. 7B-52
DTC B1511: Temperature Control Actuator (Position Sensor) and/or Its Circuit
Malfunction ...................................................... 7B-53
DTC B1512: Air flow Control Actuator (Position Sensor) and/or Its Circuit
Malfunction ...................................................... 7B-55
DTC B1513: Temperature Control Actuator and/or Its Circuit Malfunction .......................... 7B-57
DTC B1514: Air Flow Co ntrol Actuator and/or
Its Circuit Malfunction ...................................... 7B-60
DTC B1541: HVAC Control Module Back-Up Power Supply Malfunction .............................. 7B-62
DTC B1546: A/C Refrigerant Pressure Malfunction ...................................................... 7B-63
DTC B1551: Serial Communication Circuit Malfunction ...................................................... 7B-63
DTC B1552: Serial Communication Signal Malfunction ...................................................... 7B-64
DTC B1553: CAN Communication Signal Malfunction ...................................................... 7B-65
DTC B1557: Vehicle Speed Sensor Signal Malfunction ...................................................... 7B-65
DTC B1561: Engine Coolant Temperature Sensor Signal Malfunctio n .............................. 7B-66 DTC B1562: Outside Air Temperature Sensor
Signal Malfunction ........................................... 7B-66
DTC B1563: A/C Refr igerant Pressure
Sensor Signal Malfunction .............................. 7B-66
Inspection of HVAC Control Module and Its Circuit .............................................................. 7B-67
A/C System Performance Inspection ................ 7B-70
A/C System Inspection at ECM ......................... 7B-70
Repair Instructions ............ ................................7B-71
Operation Procedure for Refrigerant Charge .... 7B-71
HVAC Unit Components ................................... 7B-72
HVAC Unit Removal and In stallation ................ 7B-73
Temperature Control Actuator Removal and Installation ....................................................... 7B-73
Temperature Control Actuat or Inspection ......... 7B-73
Air Flow Control Actuator Removal and Installation ....................................................... 7B-74
Air Flow Control Actuator Inspection ................. 7B-74
Air Intake Control Actuator Removal and Installation ....................................................... 7B-75
Air Intake Control Actuator Inspection............... 7B-75
Actuator Linkage Inspection .............................. 7B-76
Blower Motor Controller Removal and Installation ....................................................... 7B-76
Blower Motor Controller Inspection ................... 7B-76
HVAC Control Module Removal and Installation ....................................................... 7B-77
Sunload Sensor Removal and Installation ........ 7B-77
Sunload Sensor Inspection ............................... 7B-77
Outside Air Temperature Sensor Removal and Installation ................................................ 7B-77
Outside Air Temperature Sensor Inspection ..... 7B-77
Inside Air Temperature Sensor Removal and Installation ....................................................... 7B-78
Inside Air Temperature Sens or Inspection ........ 7B-78
Condenser Assembly On-Vehicle Inspection .... 7B-78
Condenser Assembly Removal and Installation ....................................................... 7B-78
Receiver/Dryer Removal and Installation .......... 7B-78
Evaporator Inspection ....................................... 7B-78
Evaporator Temperature Sensor Removal and Installation ................................................ 7B-78
Evaporator Temperature Se nsor Inspection ..... 7B-78
Expansion Valve Removal an d Installation ....... 7B-78
Expansion Valve Inspection .............................. 7B-78
A/C Refrigerant Pressure Sensor and Its Circuit Inspection............................................. 7B-78
A/C Refrigerant Pressu re Sensor Removal
and Installation ................................................ 7B-78
Compressor Relay Inspection .
.......................... 7B-78
Compressor Drive Belt Inspection and Adjustment ...................................................... 7B-78
Compressor Drive Belt Removal and Installation ....................................................... 7B-79
Compressor Assembly Removal and Installation ....................................................... 7B-79
Compressor Assembly Components................. 7B-79
Magnet Clutch Removal and Installation........... 7B-79
Magnet Clutch Inspection.................................. 7B-79
Relief Valve Inspection...................................... 7B-79
Page 950 of 1496

Downloaded from www.Manualslib.com manuals search engine 7B-2 Air Conditioning System: Manual Type
Refrigerant Line
• Never use heat for bending pipes. When bending a pipe , try to make its bending angle as smooth as possible.
• Keep internal parts of air conditioning free from moistu re and dirt. When disconnecting any line from system, install
a blind plug or cap to the fitting immediately.
• When connecting hoses and pipes, apply a few drops of compressor oil (refrigerant oil) to O-ring.
• When tightening or loosening a fitting, use two wrenches, one for turning and the other for support.
• When handling recovery and recycling equipment, be sure to follow the instruction manual for the equipment.
• Check local governmental regulations regarding working with refrigerator systems and its tooling.
• Route drain hose so that drained water does not make any contact to vehicle components.
• If pipes or hoses are replaced, replenish specified amount of compressor oil to compre ssor suction side referring to
“Replenishing Compressor Oil” in “Operation Procedure for Refrigerant Charge”.
Refrigerant Recovery
When discharging refrigerant out of A/C system, always recover it by using refrigerant recovery and recycling
equipment because discharging refrigerant HFC-134a (R-1 34a) into atmosphere would cause adverse effect to
environments.
NOTE
When handling recovery and recycling equipment, be sure to follow the instruction manual for the
equipment.
Refrigerant Charge
After performing compressor oil replenishment and evacuat ion, charge a proper amount of refrigerant to A/C system
referring to “Charge” in “Operation Procedure for Refrigerant Charge”.
3
1
2
4
5
I4RS0B720001-02
1. Suction hose : Apply compressor oil (refrigerant oil) to O-ring. 4. Expansion valve
: Apply compressor oil (refrigerant oil) to O-ring.
2. Discharge hose : Apply compressor oil (refrigerant oil) to O-ring. 5. A/C refrigerant pressure sensor
: Apply compressor oil (refrigerant oil) to O-ring.
3. Liquid pipe : Apply compressor oil (refrigerant oil) to O-ring.
Page 952 of 1496

Downloaded from www.Manualslib.com manuals search engine 7B-4 Air Conditioning System: Manual Type
Sub-Cool A/C System DescriptionS7RS0B7211003
In the sub-cool A/C system (condenser integrated with receiver/dryer), the inside of the condenser is divided into the
condensation part and the sub-cooler part, and the receiver/dryer is located between those. In the receiver/dryer, the
refrigerant is separated into the vapor refrigerant and the liqui d refrigerant. Only the liquid refrigerant is delivered to the
sub-cooler part of the condenser. The refrigerant is supercooled by the sub-cooler part of the condenser.
A/C Operation DescriptionS7RS0B7211004
ECM controls the radiator fan relay and the compressor relay by following signals.
• ON/OFF signal of A/C switch
• A/C refrigerant pressure sensor
• Evaporator thermistor (evaporator temperature sensor)
• ECT sensor
NOTE
The signal of A/C swit ch is fed from BCM to ECM usin g CAN communication system. For CAN
communication system, refer to “CAN Communication System Description in Section 1A”.
I7RS0A721001-01
[A]: Liquid 2. Magnet clutch 6. Expansion valve10. Desiccant
[B]: Vapor 3. Condenser 7. A/C evaporator11. Filter
[C]: Superheated vapor 4. Receiver/dryer (Modulator) 8. Condensation part12. Vapor refrigerant
1. Compressor 5. Refrigerant pressure sensor 9. Sub-cooler part 13. Liquid refrigerant
Page 954 of 1496

Downloaded from www.Manualslib.com manuals search engine 7B-6 Air Conditioning System: Manual Type
A/C System Wiring DiagramS7RS0B7212002
BLK/REDBLK/RED
BLK/YELBLK/YEL
BLK/YEL
BRN/WHT
12V5V
5V 5V
5V11
E23-1
E23-60
BLK/REDBLK/REDE23-16
E23-57WHT/BLK
9
13
E23-55C37-14GRY/REDRED
BLK
ORN
E23-47 GRY
WHTBLU/YEL
RED/BLK
14 3
1
15
5
7
BLK
2
M
12VBLU/WHTE23-19
C37-24
C37-55ORN
5V
LT GRN16
G18-3
G18-4
G18-7
G18-8
G18-10
G18-13
G18-5
G18-6
G19-5
G19-2
G19-3
G19-7
G19-6
G19-1
G18-9
G18-14
BLK/WHT
YEL
BLU/WHT
RED
BRN/WHT
GRN/WHT
RED/BLK
RED
GRN
BRN
BLK/RED
RED/YEL
BLK
BLK/YEL
BLK/ORN
4
6
12
10
M
E23-54
REDWHTE23-3E23-18
17 18
LT GRNE23-46
L+
L–
H–
H
+
BLU/RED
BLK
BLU/WHTBLK
BLU/BLK
20
GRN
GRY
E23-48
19
21
22
BLU/REDC37-58
C37-15 C37-30
BLK/ORN
BLKBLKE23-31 BLK
BLU
YEL
GRN
WHT
23
24
26 25
28
27
8
29
I7RS0B721001-01
1. Ignition switch
9. A/C refrigerant pressure sensor 17. I ndividual circuit fuse box (No.1) 25. Air intake selector
2. Blower motor 10. ECM 18. Main fuse box 26. Rear defogger switch
3. HVAC control unit 11. Main relay 19. Radiator cooling fan relay No.1 27. Rear defogger
4. Lighting switch 12. Air intake control actuator 20. Radiator cooling fan relay No.2 28. Rear defogger relay
5. Blower motor relay 13. Compressor relay 21. Radiator cooling fan relay No.3 29. ABS / ESP ® control module
6. Blower motor resistor 14. Compressor 22. Radiator cooling fan motor
7. Junction block assembly 15. Evaporator thermistor (evaporator temperature sensor)23. Blower speed selector
8. BCM 16. ECT sensor 24. A/C switch
Page 955 of 1496

Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Manual Type 7B-7
Diagnostic Information and Procedures
A/C System Symptom DiagnosisS7RS0B7214001
ConditionPossible cause Correction / Reference Item
No cool air comes out (A/
C system does not
operate) No refrigerant
Perform recovery, evacuation and charge
referring to “Operation Procedure for
Refrigerant Charge”.
Fuse blown Check related fuses, and then check for short
circuit to ground.
A/C switch faulty Check A/C switch referring to “A/C Switch
Inspection”.
Blower speed selector faulty Check blower speed selector referring to
“Blower Speed Selector Inspection in Section
7A”.
Evaporator thermistor (Evaporator
temperature sensor) faulty Check evaporator thermistor (evaporator
temperature sensor) referring to “Evaporator
Thermistor (Evaporator Temperature Sensor)
Inspection”.
A/C refrigerant pressure sensor faulty Check A/C refrigerant pressure sensor
referring to “A/C Refrigerant Pressure Sensor
and Its Circuit Inspection”.
Wiring or grounding faulty Repair as necessary.
ECM faulty Check ECM referring to “A/C System
Inspection at ECM”.
Magnet clutch faulty Check magnet clutch referring to “Magnet
Clutch Inspection”.
Compressor drive belt loosened or
broken Adjust or replace drive belt.
Compressor faulty Check compressor.
Compressor relay faulty Check compressor relay referring to
“Compressor Relay Inspection”.
BCM faulty Check BCM referring to “Inspection of BCM
and its Circuits in Section 10B”.
No cool air comes out
(radiator cooling fan
motor does not operate) Fuse blown
Check related fuses, and then check for short
circuit to ground.
Wiring or grounding faulty Repair as necessary.
Radiator cooling fan motor relay faulty Check radiator cooling fan motor relay
referring to “Radiator Cooling Fan Relay
Inspection in Section 1F”.
Radiator cooling fan motor faulty Check radiator cooling fan motor referring to
“Radiator Cooling Fan Removal and
Installation in Section 1F”.
ECM and/or its circuit faulty Check ECM and/or its circuit referring to “A/C
System Inspection at ECM”.
No cool air comes out
(blower motor does not
operate) Fuse blown
Check related fuses, and then check for short
circuit to ground.
Blower motor relay faulty Check blower motor relay referring to “Blower
Motor Relay Inspection in Section 7A”.
Blower motor resistor faulty Check blower motor resistor referring to
“Blower Motor Resistor Inspection in Section
7A”.
Blower speed selector faulty Check blower speed selector referring to
“Blower Speed Selector Inspection in Section
7A”.
Wiring or grounding faulty Repair as necessary.
Blower motor faulty Check blower motor referring to “Blower Motor
Inspection in Section 7A”.
Page 957 of 1496

Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Manual Type 7B-9
Abnormal Noise Symptom Diagnosis of A/C SystemS7RS0B7214002
Abnormal Noise from Compressor
Abnormal Noise from Magnetic Clutch
Abnormal Noise from Tubing
Abnormal Noise from Condenser Assembly
Abnormal Noise from Crankshaft PulleyInsufficient airflow of
cooled air
A/C evaporator clogged or frosted
Check A/C evaporator and evaporator
thermistor (evaporator temperature sensor)
referring to “Evaporator Inspection” and
“Evaporator Thermistor (Evaporator
Temperature Sensor) Inspection”.
Air leaking from HVAC unit or air duct Repair as necessary.
Blower motor faulty Check blower motor referring to “Blower Motor
Inspection in Section 7A”.
Wiring or grounding faulty Repair as necessary.
Condition Possible cause Correction / Reference Item
Condition
Possible cause Correction / Reference Item
During compressor
operation, a rumbling
noise is heard
proportional to engine
revolutions Inadequate clearance in scroll area
Replace compressor.
A loud noise is heard at a
certain rpm,
disproportionately to
engine revolution Loose or faulty compressor drive belt
Adjust drive belt tension or replace drive belt.
Loose compressor mounting bolts Retighten mounting bolts.
A loud rattle is heard at
low engine rpm Loose compressor clutch plate bolt
Retighten clutch plate bolt.
Replace compressor if it was operated in this
condition for a long time.
Condition Possible cause Correction / Reference Item
A rumbling noise is heard
when compressor is not
in operation Worn or damaged bearings
Replace magnet clutch assembly.
A chattering noise is
heard when compressor
is in operation Faulty magnet clutch clearance
(excessive clearance)
Adjust magnet clutch clearance.
Worn magnet clutch friction surface Replace magnet clutch assembly.
Compressor oil leaked from shaft seal,
contaminating the friction surface Replace compressor body assembly.
Condition
Possible cause Correction / Reference Item
A droning noise is heard
from inside of the vehicle,
but not particularly
noticeable in engine
compartment Faulty tubing clamps
Reposition clamps or increase the number of
clamps.
Resonance caused by pulsation from
variations in re frigerant pressure Attach a silencer to tubing, or modify its
position and length.
Condition
Possible cause Correction / Reference Item
Considerable vibration in
condenser assembly Resonance from condenser assembly
bracket and body Firmly insert a silenc
er between condenser
assembly bracket and body.
Condition Possible cause Correction / Reference Item
A large rattling noise is
heard at idle or sudden
acceleration Loosen crankshaft pulley bolt
Retighten bolt.