Ground SUZUKI SWIFT 2008 2.G Service Workshop Manual
Page 916 of 1496
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P/S Control Module Power Supply and Ground Circuit CheckS7RS0B6304022
Wiring Diagram
1
[A ]
123
4 5 67
89
11
10
12 13
141516
17 18 19 20
[B ]
7
1
2
MBLK
REDE51-1
E51-2
12V
 LT  GRN 
/BLKE52-1 E49-1
GRNGRNWHTBLK
WHY
3
3
5
6
1 2
E49-2BLK
I7RS0B630012-01
[A]: Connector “E52” (viewed from harness side)
2. Ignition switch5. “EPS” fuse
[B]: Connector “E49” (viewed from harness side) 3. Individual circuit fuse box No.1 6. “IG1 SIG” fuse
1. Main fuse box 4. Junction block assembly7. P/S control module
StepAction YesNo
1 Circuit fuse check
1) Disconnect P/S control modu le connector with ignition 
switch turned OFF.
2) Check for proper connection to P/S control module  connector at “E49-1”, “E49-2” and “E52-1” terminals.
3) If OK, check “P/S” fuse and “IG1 SIG” fuse for blowing.
Are “P/S” fuse and “IG1 SIG” fuse in good condition? Go to Step 2.
Replace fuse(s) and 
check for short in 
circuits connected to 
fuse(s).
2 Power supply circuit check
1) Measure voltage between “E49-1” terminal of P/S 
control module connector and body ground.
Is voltage 10 - 14 V? Go to Step 3.
“GRN” or “BLK” wire is 
open circuit.
3 Ignition signal check
1) Turn ignition switch to ON position.
2) Measure voltage between “E52-1” terminal of P/S 
control module connector and body ground.
Is voltage 10 - 14 V? Go to Step 4.
“LT GRN/BLK” or “GRN” 
wire is open circuit.
4 P/S control module ground circuit check
1) Turn ignition switch to OFF position.
2) Disconnect connectors from P/S control module.
3) Measure resistance between “E49-2” terminals of P/S 
control module connector and body ground.
Is resistance 1 
Ω or less? Go to Step 5. “BLK” wire is open or 
high resistance circuit.  
Page 917 of 1496
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Inspection of P/S Control Module and Its CircuitsS7RS0B6304023
The P/S control module (1) and its circuits can be checked at the P/S control module wiring couplers (2) by measuring 
voltage and resistance.
CAUTION! 
P/S control module cannot be checked by itself. It is strictly prohibited to connect voltmeter or 
ohmmeter to the P/S control module with connectors disconnected from the P/S control module.
 
5 P/S control module ground circuit check
1) Connect connectors to P/S control module.
2) Start engine.
3) Measure voltage between “E49-2” terminals of P/S 
control module connector and body ground when 
steering wheel fully turned to left or right.
Is voltage 0.3 V or less? P/S Control Module 
Power Supply and 
Ground Circuit is in 
good condition.
“BLK” wire is open or 
high resistance circuit.
Step Action Yes No
[A]
12
3
4 5 67
89
11
10
12 13
141516
17 18 19 20
[B]
[C]
12
1
1 2
2
I6RS0C630016-03
[A]: Connector “E52” (viewed from harness side) [C]: Connector “E49” (viewed from harness side)
[B]: Connector “E51” (viewed from harness side)  
Page 918 of 1496
Downloaded from www.Manualslib.com manuals search engine 6C-36 Power Assisted Steering System: 
Voltage Check1) Remove console box.
2) Check for voltage at each terminal with co nnectors connected to the P/S control module.
NOTE
As each terminal voltage is affected by the battery voltage, confirm if the battery voltage is 11 V or 
more when ignition switch is ON.
*: The voltage of this circuit may not be checked by voltmeter. If so, use oscilloscope.
 
Terminal Wire colorCircuit Normal voltage Remarks
E49-1 GRN Main power supply for 
internal memory and P/S 
motor 10 – 14 V
—
E49-2 BLK Ground for P/S control 
module Below 0.3 V
—
E51-1 BLK Motor output 1 *0 – 1 V
↑↓
10 – 14 V
(“Reference 
waveform No.1: ”,  “Reference 
waveform No.2: 
”and “Reference 
waveform No.3: ”) • Engine idling and steering wheel at 
straight position
• Voltage between “E51-1” and vehicle  body ground
E51-2 RED Motor output 2 *0 – 1 V
↑↓
10 – 14 V
(“Reference 
waveform No.1: ”,  “Reference 
waveform No.2: ”  and “Reference 
waveform No.3: ”) • Engine idling and steering wheel at 
straight position
• Voltage between “E51-2” and vehicle  body ground
E52-1 LT GRN/BLK Ignition switch signal for P/S 
control module 10 – 14 V Ignition switch ON
E52-2 — —— —
E52-3 — —— —
E52-4 PPL Vehicle speed signal *0 – 1 V
↑↓
8 – 14 V
(“Reference 
waveform No.9” 
under “Inspection of 
ECM and Its Circuits  in Section 1A”.) • Ignition switch ON
•Front left tire tu
rned quickly with right 
tire locked
E52-5 GRY “EPS” warning light 0 V “EPS” warning light OFF
E52-6 BLU Torque sensor signal (Sub) About 0 – 2.5 V
• Steering wheel with left turn
• Out put voltage varies linearly 
depending on steering force
About 2.5 V Steering wheel at free
About 2.5 – 6 V • Steering wheel with right turn
• Out put voltage varies linearly 
depending on steering force
E52-7 — —— —
E52-8 GRN Main power supply for torque 
sensor About 12 V• Ignition switch ON
• Check voltage between “E52-8” and 
“E52-9” terminals
E52-9 BRN Ground for torque sensors Below 0.3 V —
E52-10 — —— —  
Page 919 of 1496
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E52-11 PPL/WHT Data link connector——
E52-12 BRN Engine speed signal *0 – 1 V
↑↓
8 – 14 V
(“Reference 
waveform No.30”  and “Reference 
waveform No.31” 
under “Inspection of 
ECM and Its Circuits  in Section 1A”.) Engine idling
E52-13 — —— —
E52-14 RED/BLU P/S operation signal (idle up 
signal) About 12 V Ignition switch ON
0 – 1 V Engine idling and turned steering 
wheel to the right or left until it stops
E52-15 — —— —
E52-16 YEL Torque sensor internal failure 
signal About 5 V At the moment of Ignition switch ON
0 V Ignition switch ON
E52-17 — —— —
E52-18 WHT Torque sensor signal (Main) About 0 – 2.5 V
• Steering wheel with left turn
• Out put voltage varies linearly 
depending on steering force
About 2.5 V Steering wheel at free
About 2.5 – 6 V • Steering wheel with right turn
• Out put voltage varies linearly 
depending on steering force
E52-19 GRY Ground for shield wire Below 0.3 V—
E52-20 RED 5 V reference power supply 
for torque sensor About 5 V• Ignition switch ON
• Check voltage between “E52-20” 
and “E52-9” terminals
Terminal Wire color
Circuit Normal voltage Remarks  
Page 920 of 1496
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Reference waveform No.1
Motor output signal 1(1), Motor output signal 2(2), with 
engine idlingReference waveform No.2
Motor output signal 1(1), Motor output signal 2(2), with 
engine idling
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 
at straight position
I6RS0B630017-01
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 µ
s/DIV 
Measurement 
condition • Engine is idling and steering wheel 
is turned to left or right at turning 
speed of 90 ° /sec
[A]: Steering wheel is turned left at turning speed of 90 ° /sec
[B]: Steering wheel is turned right at turning speed of 90 ° /sec
[C]: 12 V ON
[D]: GND ON [E]: 1 duty cycle
I6RS0B630018-01  
Page 921 of 1496
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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 929 of 1496
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P/S Motor and Its Circuit InspectionS7RS0B6306013
1) Remove console box.
2) Disconnect motor connector (“E51”) from P/S control module with ignition switch OFF.
3) Check for resistance between terminals of motor  connector (“E51”).
If check result is not as specified, replace steering 
gear case assembly.
Motor circuit resistance
4) Check for continuity between terminal of motor connector (“E51”) and body ground.
If check result is not as specified, replace steering 
gear case assembly.
Motor circuit resistance
5) Hoist vehicle.
6) Connect “E51” connector to P/S control module with  ignition switch OFF position.
7) Using ammeter (2), check that P/S motor (1) current  is as following table with id ling engine. If check result 
is not satisfactory, check P/S control module 
referring to “Inspection of P/S Control Module and Its 
Circuits”. If OK, replace steering gear case 
assembly.
Motor current at hoisted vehicle
“E51-1” and “E51-2” (For motor) About 1  Ω
“E51-2” and body ground No continuity 
1. Connector “E51” (viewed from harness side)
E51
11 2
I6RS0C630025-01
Condition When 
steering 
wheel is left  at straight 
position: [A] When 
steering 
wheel is 
turned left or  right by turning 
speed with 
90°  /sec: [B] When 
steering 
wheel is kept  fully turned left or right 
until it stops.:  [C]
Motor 
current Approx. 0 A Approx.
0 – 4 A Approx.
30 – 45 A
1
32
E51-1
E51-2
[C] [A]
[B] [B]
I6RS0C630022-01  
Page 939 of 1496
Downloaded from www.Manualslib.com manuals search engine Heater and Ventilation:  7A-3
Diagnostic Information and Procedures
Heater and Ventilation Symptom DiagnosisS7RS0B7104001
ConditionPossible cause Correction / Reference Item
Blower motor does not 
operate with blower 
speed selector ON 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”.
Blower motor resistor faulty Check blower motor resistor referring to 
“Blower Motor Resistor Inspection”.
Blower speed selector faulty Check blower speed selector referring to 
“Blower Speed Selector Inspection”.
Blower motor faulty Check blower motor referring to “Blower Motor 
Inspection”.
Wiring or grounding faulty Repair as necessary.
Incorrect temperature 
output Temperature control cable broken or 
bent (manual A/C) Check temperature control cable.
Temperature control lever faulty (manual 
A/C) Check temperature control lever.
Incorrect installation of temperature 
control cable (manual A/C) Check position and adjust it as necessary.
Temperature control door assembly 
broken Repair temperature control door assembly.
Air ducts clogged Repair air ducts.
Heater core leaked or clogged Replace heater core.
Heater hoses leaked or clogged Replace heater hoses.
Thermostat faulty Check thermostat referring to “Thermostat 
Inspection in Section 1F”.
Temperature control actuator faulty 
(automatic A/C) Check temperature control actuator referring to 
“Temperature Control Actuator Inspection in 
Section 7B”.
HVAC control module faulty (automatic 
A/C) Check HVAC control module referring to 
“Inspection of HVAC Control Module and Its 
Circuit in Section 7B”.
Wiring or grounding faulty (automatic A/
C) Repair as necessary.
Air outlet port does not 
change or does not agree 
with air flow selector’s 
position even if air flow 
selector is changed Air flow control cable broken or bent 
(manual A/C)
Check air flow control cable.
Air flow control lever faulty (manual A/C) Check air flow control lever.
Incorrect installation of air flow control 
cable (manual A/C) Check position and adjust it as necessary.
Air flow control door assembly broken Repair air flow control door assembly.
Air ducts leaked or clogged Repair air ducts.
Air flow control actuator faulty 
(automatic A/C) Check air flow control actuator referring to “Air 
Flow Control Actuator 
Inspection in Section 
7B”.
HVAC control module faulty (automatic 
A/C) Check HVAC control module referring to 
“Inspection of HVAC Control Module and Its 
Circuit in Section 7B”.
Wiring or grounding faulty (automatic A/
C) Repair as necessary.
Air intake door does not 
change even if air intake 
mode is changed Air intake door broken
Repair air intake door.
Air intake control actuator faulty Check air intake control actuator referring to 
“Air Intake Control Actuator Inspection”.
Air intake selector faulty Check air intake selector referring to “Air Intake 
Selector Inspection”.
Wiring or grounding faulty Repair as necessary.  
Page 955 of 1496
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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
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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.