2006 SUZUKI SWIFT Inspection of BCM

Downloaded from www.Manualslib.com manuals search engine 5A-70 Automatic Transmission/Transaxle:
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure
1) Connect scan tool to DLC with ignition switch OFF.
2) Clear DTCs in TCM and ECM memories by us ing scan tool and turn ignition switch ON.
3) Shift select lever to each of “L”, “2”, “3”, “D”, “N”, “R” and “P” ranges for 20 seconds each.
4) Check DTC, pending DTC and freeze-frame data.
DTC Troubleshooting DTC detecting condition Trouble area
“3” position switch ON signal is inputted although transmission range
switch signal is inputted P, R, N or L. range. • “3” position switch or its circuit malfunction
•BCM
•TCM
Step
Action YesNo
1 Was “A/T System Check” performed? Go to Step 2.Go to “A/T System
Check”.
2 “3” position switch circuit for operation
1) Connect SUZUKI scan tool to DLC with ignition switch
OFF.
2) Turn ignition switch ON and check “3” position switch signal on scan tool data display when shifting select
lever to each range.
Does indicate “3” position swit ch (O/D OFF switch) condition
OFF when shifting select lever to “P”, “R”, “N” and “L” range? Substitute a known-
good TCM and recheck.
Go to Step 3.
3 “3” position switch signal inspection
With ignition switch ON, check voltage between “L01-8”
terminal of BCM coupler and ground.
“3” position switch specifications
Shift select lever to “3” or “2” range: Battery voltage
Shift select lever to other above range: 0 V
Is the result as specified? Substitute a known-
good BCM and recheck.
Go to Step 4.
4 Check “3” position switch operation
Is it in good condition? “LT GRN” wire shorted
to ground.
Replace “3” position
switch.

Downloaded from www.Manualslib.com manuals search engine 5A-72 Automatic Transmission/Transaxle:
DTC Troubleshooting
NOTE
Upon completion of inspection and repair work, perform “DTC Confirmation Procedure:” and confirm
that the trouble has been corrected.

Step Action YesNo
1 Was “A/T System Check” performed? Go to Step 2.Go to “A/T System
Check”.
2 Control module connector check
1) Check connection of connectors of all control modules
communicating by means of CAN.
2) Recheck DTC.
Is there DTC P1774? Go to Step 3.
Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”
3 CAN communication circuit check
1) Turn ignition switch to OFF position.
2) Disconnect connectors of all control modules
communicating by means of CAN.
3) Check CAN communication circuit between control modules for open, short and high resistance.
Is each CAN communication circuit in good condition? Go to Step 4.
Repair circuit.
4 DTC check
1) Turn ignition switch to OFF position.
2) Connect connectors of disconnected control modules
communicating by means of CAN.
3) Disconnect connector from any one of control modules other than BCM and TCM.
4) Recheck TCM for DTC.
Is DTC P1774 detected? Disconnect connectors
of control modules other
than the one whose
connector is
disconnected in Step 3)
one by one and check
that DTC P1774 is
detected by TCM each
time connector is
disconnected. When
DTC P1774 is not
detected by TCM while
checking in this way, go
to description under
“NO” below. If DTC
P1774 is detected by
TCM, go to Step 5.Check power and
ground circuit of control
module disconnect in
Step 3). If circuit is OK,
substitute a known-
good control module
disconnected in Step 3)
and recheck.
5 DTC check of BCM
1) Turn ignition switch to OFF position.
2) Disconnect connector from all control modules other
than BCM.
3) Check BCM for DTC referring to “DTC Check in Section 10B”
Is DTC U1073 (No. 1073) detected? Substitute a known
good BCM and recheck.
Substitute a known
good TCM and recheck.

Downloaded from www.Manualslib.com manuals search engine 5A-74 Automatic Transmission/Transaxle:
DTC P1778: TCM Lost Communication with BCM (Reception Error)S7RS0B5104041
Wiring Diagram
Refer to “DTC P1774: CAN Communication Bus Off”.
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure
1) Connect scan tool to DLC with ignition switch OFF.
2) Clear DTC.
3) Start engine and run it for 1 min. or more.
4) Check DTC.
DTC Troubleshooting
NOTE
Upon completion of inspection and repair work, perform “DTC Confirmation Procedure:” “DTC
Confirmation Procedure” and confirm that the trouble has been corrected.

DTC detecting condition Trouble area
Reception error of communication data fo r BCM is detected more than specified
time continuously. •ECM
•TCM
•BCM
• ABS control module
• CAN circuit
Step
Action YesNo
1 Was “A/T System Check” performed? Go to Step 2.Go to “A/T System
Check”.
2 Control module connector check
1) Check connection of connectors of all control modules
communicating by means by means of CAN.
2) Recheck DTC.
Is there DTC P1778? Go to Step 3.
Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”.
3 DTC check in BCM (bus off)
1) Check BCM for DTC referring to “DTC Check in Section
10B”.
Is there DTC U1073? Go to “DTC U1073 (No.
1073): Control Module
Communication Bus Off
in Section 10B”.
Go to Step 4.
4 DTC check in ABS control module
1) Check ABS control module for DTC referring to “DTC
Check in Section 4E”.
Is there DTC U1100? Go to “DTC U1100: Lost
Communication with
ECM (Reception Error)
in Section 4E”.
Go to Step 5.
5 DTC check in ECM
1) Check ECM for DTC referring to “DTC Check in Section
1A”.
Is there DTC P1678? Check BCM power and
ground circuit. If circuit
is OK, substitute a
known-good BCM and
recheck.Go to Step 6.
6 CAN communication circuit check
1) Turn ignition switch to OFF position.
2) Disconnect connectors of all control modules
communicating by means of CAN.
3) Check CAN communication circuit between control modules for open, short and high resistance.
Is each CAN communication circuit in good condition? Check TCM power and
ground circuit. If circuit
is OK, substitute a
known-good TCM and
recheck.
Repair circuit.

Downloaded from www.Manualslib.com manuals search engine 6C-12 Power Assisted Steering System:
Scan Tool Data Definitions
Battery Voltage
This parameter indicates battery positive voltage.
TQS Power Supply (Torque Sensor Power Supply, V)
This parameter indicates the power supply voltage which
the P/S control module supplies to the torque sensor.
TQS Main Torque (Torque Sensor Main Torque, N ⋅m)
The torque sensor is installed to detect the steering force
and the steering directio n. It consists of two
potentiometers and the main torque sensor is one of
these.
TQS Sub Torque (Torque Sensor Sub Torque, N ⋅m)
The torque sensor is installed to detect the steering force
and the steering directio n. It consists of two
potentiometers and the sub-torque sensor is one of
these. Its output characteristics are compared with those
of the main torque sensor.
Assist Torque (N ⋅m)
This parameter is an internal parameter of the P/S
control module. It is obtained by computing the torque
sensor input signal. Motor Control (Motor Control Current, A)
Based on the input signal, the P/S control module
determines the assist amount
and controls the current to
the motor suitable for that a ssist amount. This parameter
indicates that control value.
Motor Monitor (Motor Monitor Current, A)
This parameter indicates the actually measured value of
the current flowing to the motor. The motor circuit
condition is diagnosed by co mparing this parameter with
“Motor Control” parameter described previously.
Vehicle Speed (km/h, MPH)
Vehicle speed signal is fed from BCM. P/S control
module determines the amount of power assist based on
this vehicle speed signal and the torque sensor signal.
Engine Speed (rpm)
Engine speed signal is fed from the ECM so that it can
be used for trouble diagnos is of the electric power
steering system.
Motor Volt (V)
This parameter indicates the voltage between motor
terminals.
Ignition switch (ON, OFF)
This parameter indicates the condition of the power
supply through the ignition switch.
Visual InspectionS7RS0B6304007
Visually check the following pats and system.
P/S System Symptom DiagnosisS7RS0B6304008
This section describes trouble diagnosis of the P/S system parts whose trouble is not indicated by the on-board
diagnostic system (self-diagnostic functi on). When no malfunction is indicated by the on-board diagnostic system
(self-diagnosis function) and those stee ring basic parts as described in “Steering Symptom Diagnosis in Section 6A”
are all in good condition, check the following power steer ing system parts which may be a possible cause for each
symptom of the steering. Inspection Item Referring section
Battery Level, leakage, color “Batte ry Description in Section 1J”
Connectors of electric wire
harness Disconnection friction “Intermittent and Poor
Connection Inspection in Section 00”
Fuses Burning “Cautions in Body Electric al System Servicing in Section 9A”
Parts Installation, damage
Other parts that can be checked visually
Condition Possible cause Correction / Reference Item
Steering wheel feels
heavy (Perform “Steering
Force Check” before
diagnosis.) Steering wheel installed improperly
(twisted)
Install steering wheel correctly.
Poor performance of torque sensor Check torque sensor referring to “Torque
Sensor and Its Circuit Inspection”.
Poor performance of P/S motor Check motor referring to “P/S Motor and Its
Circuit Inspection”.
Steering gear case assembly faulty Replace.
Poor performance of vehicle speed
signal from ECM Check vehicle speed signal circuit referring to
“DTC C1121 / C1123 / C1124: VSS Circuit
Failure”.

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Serial Data Link Circuit CheckS7RS0B6304009
CAUTION!
Be sure to perform “EPS System Check” before starting “Troubleshooting”.

Wiring DiagramVehicle pulls to one side
during straight driving
Poor performance of torque sensor
Check torque sensor referring to “Torque
Sensor and Its Circuit Inspection”.
Steering gear case assembly faulty Replace.
Poor recovery after turns Poor performance of torque sensor Check torque sensor referring to “Torque
Sensor and Its Circuit Inspection”.
Steering column faulty Replace.
Abnormal noise P/S motor (built in steering gear case
assembly) malfunction Replace steering gear case assembly.
No idle up P/S control module faulty Check P/S control module referring to
“Inspection of P/S Control Module and Its
Circuits”.
Condition Possible cause Correction / Reference Item
MBLK
RED
E52-11 E51-1
E51-2PPL/WHT
[A ]
12
3
4 5 67
89
11
10
12 13
141516
17 18 19 2010 9 8 7654 3 21
16 15 14 13 12 11
26 25 24 2322 21 20 19 18 17
32 31 30 29 28 27
[C]
8
79
12V
[B ]
11
12
GRY
LT GRN
/BLK
E52-1
E52-5
E49-1
GRNGRNWHTBLK
WHY
G28-25G28-31
RED/BLK
10
3
4
4
5 6
4
4
1 2
4
E49-2BLK
I7RS0B630003-01
[A]: Connector “E52” (viewed from harness side) 3. Junction block assembly 8. P/S control module
[B]: Connector “E49” (viewed from harness side) 4. Fuse 9. T o ECM, BCM, Air bag SDM control module and ABS control
module assembly
[C]: Connector “G28” (viewed from harness side) 5. Comb ination meter 10. Individual circuit fuse box No.1
1. Main fuse box 6. “EPS” warning light 11. Serial data circuit
2. Ignition switch 7. Date link connector (DLC)

Downloaded from www.Manualslib.com manuals search engine 7A-6 Heater and Ventilation:
Blower Motor Relay InspectionS7RS0B7106007
1) Remove junction block assembly referring to “BCM (Included in Junction Block Assembly) Removal and
Installation in Section 10B”.
2) Disconnect blower motor relay (1) from junction block assembly (2).
3) Check that there is no continuity between terminal “C” and “D”. If there is continuity, replace relay.
4) Connect battery positive (+ ) terminal to terminal “B”
of relay. Connect battery negative (–) terminal “A” of
relay.
Check continuity between terminal “C” and “D”.
If there is no continuity wh en relay is connected to
the battery, replace relay.
HVAC Control Unit ComponentsS7RS0B7106008
“D”
“B” “A”
“C”
1
2
I4RS0B710008-01
45
61
7
10
9
238
I4RS0B710009-01
1. Heater control body assembly 4. Bulb 7. Air intake selector10. Rear defogger switch (if equipped)
2. Air flow selector 5. Temperature control cable 8. Temperature selector
3. Blower speed selector 6. Air flow control cable9. A/C switch (if equipped)

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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”.

Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Automatic Type 7B-39
Diagnostic Information and Procedures
A/C System Symptom DiagnosisS7RS0B7224001
4. Rear defogger relay 15. Evaporator temperature sensor 26. Radiator cooling fan relay No.1 37. Rear defogger switch
5. Rear defogger 16. Sunload sensor 27. Radiator cooling fan relay No.2 38. To BCM
6. Blower motor relay 17. Junction block assembly 28. Radiator cooling fan relay No.3 39. To ECM
7. Blower motor 18. ECM 29. Information display 40. To main relay
8. Blower motor controller 19. ECT sensor 30. Lighting switch 41. To main fuse
9. DLC 20. Radiator cooling fan motor 31. A/C switch 42. Back-light
10. Air intake actuator 21. Compressor relay 32. MODE (air flow) selector 43. Defroster indicator 11. Air flow control actuator 22. Compressor 33. Air intake selector 44. Rear defogger indicator
Condition Possible 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 “Inspection of
HVAC Control Module and Its Circuit”.
Evaporator temperature sensor faulty Check 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.
ECT sensor faulty Check ECT sensor referring to “ECT Sensor
Inspection in Section 1C”.
ECM faulty Check ECM referring to “A/C System
Inspection at ECM”.
HVAC control module faulty Check HVAC control module referring to
“Inspection of HVAC Control Module and Its
Circuit”.
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”.
Temperature selector, blower speed
selector, and/or air flow selector faulty Check HVAC control module referring to
“Inspection of HVAC Control Module and Its
Circuit”.
BCM faulty Check BCM referring to “Inspection of BCM
and its Circuits in Section 10B”.