troubleshooting SUZUKI SWIFT 2008 2.G Service Workshop Manual
Page 1413 of 1496
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Body Electrical Control System CheckS7RS0BA204002
Interior light• Each door switch
• Key reminder switch • Interior light
Warning buzzer • Key reminder switch
• Tail light switch
• Driver side door switch
• TCM (reverse signal) (if equipped)
• ECM (vehicle speed signal)
• Keyless start control module (if equipped) • Warning buzzer (located in BCM)
Rear end door window 
defogger • Rear end door window defogger switch
• Generator • Rear end door window defogger 
relay
Rear end door opener • Manual door lock switch (unlock signal)
• Key cylinder switch (unlock signal)
• Keyless entry transmitter (unlock signal) (if 
equipped)
• Rear end door opener switch • Rear end door opener relay
Theft deterrent light • Key reminder switch • Theft deterrent light (located in 
information display or clock)
Control Input Output
Step
Action YesNo
1  ) Customer complaint analysis
1) Perform customer complaint analysis.
Was customer complaint analysis performed? Go to Step 2.
Perform customer 
complaint analysis.
2  ) Problem symptom confirmation
1) Perform problem symptom confirmation.
Does trouble recur? Go to Step 3.
Go to Step 7.
3  ) DTC check
1) Check DTC.
Is it malfunction code? Go to Step 4.
Go to Step 5.
4  ) Troubleshooting for DTC
1) Check and repair according to DTC diag. flow.
Are check and repair completed? Go to Step 7.
Check and repair 
malfunction part(s).
5  ) Body electrical control system symptom diagnosis
1) Perform check and repair referring to “Symptom  Diagnosis” of system having a trouble.
Is there faulty condition? Repair or replace 
malfunction part(s).
Go to Step 6.
6  ) Check for intermittent problem
1) Check for interm ittent problem.
Is there faulty condition? Repair or replace 
malfunction part(s).
Go to Step 7.
7  ) Final confirmation test
1) Clear DTC referring to “DTC Clearance”.
2) Check DTC referring to “DTC Check”.
Is there any DTC? Go to Step 4.
End.  
Page 1414 of 1496
Downloaded from www.Manualslib.com manuals search engine 10B-11 Body Electrical Control System: 
Customer Complaint Analysis
Record details of the problem (failure, complaint) and how it occurred as described by the customer.
For this purpose, use of such a questionnaire form as shown in figure will facilitate collectin g information to the point 
required for proper analysis and diagnosis. Customer questionnaire (example)
Problem Symptom Confirmation
Check if what the custom er claimed in “Customer 
Questionnaire” is accurately f ound in the vehicle. If that 
symptom is found, check whether the symptom is 
identified as a failure. (This step should be shared with 
the customer if possible.)
DTC Check
Check DTC stored in BCM me mory referring to “DTC 
Check”, record it and then clear it referring to “DTC 
Clearance”. DTC indicates malfunction that occurred in 
the system but does not indicate  whether it exists now or 
it occurred in the past and the normal condition has been 
restored now. To check which case applies, clear DTC 
once and check whether or not any fault exists.
Troubleshooting for DTC
Based on the DTC indicated in Step 3 and referring to 
applicable DTC flow, locate the cause of the trouble, 
namely in a sensor, wire harness, connector, BCM or 
other part and repair or replace faulty parts. Body Electrical Control System Symptom Diagnosis
Check the parts or system 
suspected as a possible 
cause referring to symptom diagnosis of each system.
Check for Intermi ttent Problem
Check parts where an intermit tent trouble is easy to 
occur (e.g., wire harness, connector, etc.), referring to 
“Intermittent and Poor Connec tion Inspection in Section 
00”.
Final Confirmation Test
Confirm that the problem symptom has gone and the 
body electrical control system is free from any abnormal 
conditions. If what has been repaired is related to the 
malfunction DTC, check DTC  again and confirm that no 
DTC is indicated.
Customers name: 
  Model: 
 VIN: 
 
Date of issue: 
  Date Reg: 
 Date of problem: 
  Mileage: 
 
Problem Symptoms
Power door lock system does not operate
Keyless entry system does not operate  
Rear end door window defogger does not operate
Rear wiper does not operate
Rear end door opener does not operate  
Other            
Frequency of Occurrence 
Continuous / Intermittent (       times a day, a month) 
/ Other          
 
Environmental Condition  
Weather:  
Fine / Cloudy / Rain / Snow / Other          
 
Temperature:    (F ) 
Diagnostic Trouble Code  Normal code / Malfunction code (           )
 
Warning buzzer does not sound
Interior light does not light
Theft deterrent light does not flush
I5RS0DA20006-01  
Page 1419 of 1496
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BCM Power Circuit and Ground Circuit CheckS7RS0BA204007
Wiring Diagram
Troubleshooting
I4RS0AA20008-01
[A]: Junction block assembly connector viewed from harness side3. Ignition switch
1. BCM 4. Battery
2. Junction block assembly
Step Action YesNo
1 Fuse check
1) Turn ignition switch to OFF position.
2) Check circuit fuses for condition.
Are circuit fuses in good condition? Go to Step 2.
Replace fuse and check 
for short circuit to 
ground.
2 Power supply circuit check
1) Disconnect connectors from junction block assembly.
2) Check for proper connection to junction block assembly 
connector at terminal “E40-2”.
3) If OK, then measure voltage between “E40-2” terminal of  junction block assembly connector and vehicle body 
ground.
Is voltage 10 – 14 V? Go to Step 3.
Repair power supply 
circuit.  
Page 1420 of 1496
Downloaded from www.Manualslib.com manuals search engine 10B-17 Body Electrical Control System: 
DTC B1133 (DTC No. 1133): Battery Voltage Too HighS7RS0BA204008
Wiring Diagram
Refer to “BCM Power Circuit and Ground Circuit Check”.
DTC Detecting Conditi on and Possible Cause
Flow Test Description
Step 1: Check charging system
DTC Troubleshooting 3
Power supply circuit check
1) Check for proper connection to junction block assembly 
connector at terminals “G32-2” and “G32-5”.
2) If OK, turn ignition switch ON.
3) Measure voltage between following terminals. • Between “G32-2” terminal of junction block assembly connector and vehicle body ground
• Between “G32-5” terminal of junction block assembly  connector and vehicle body ground
Is each voltage 10 – 14 V? Go to Step 4. Repair power supply 
circuit.
4 Ground circuit check
1) Turn ignition switch to OFF position.
2) Check for proper connection to junction block assembly 
connector at terminals “G33-3”, “G34-9” and “L05-4”.
3) If OK, then measure resistance between following  terminals.
• Between “G33-3” terminal of junction block assembly connector and vehicle body ground
• Between “G34-9” terminal of junction block assembly  connector and vehicle body ground
• Between “L05-4” terminal of junction block assembly  connector and vehicle body ground
Is each resistance 2 
Ω or less? BCM power supply 
circuit and ground circuit 
are in good condition.
Repair ground circuit.
Step Action Yes No
DTC detecting condition
Possible cause
Power voltage supplied from battery to BCM is 
higher than 16V. • Charging system malfunction
• BCM malfunction
Step
Action YesNo
1 Charging system operation check
1) Check generator for operation referring to “Generator 
Test (Overcharged Battery Check) in Section 1J”.
Is it in good condition? Substitute a known 
good BCM (included in 
junction block 
assembly) and recheck.
Repair charging system.  
Page 1421 of 1496
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DTC B1141 / DTC B1142 (No. 1141 / No. 1142): Outside Air Temperature (Ambient Temp.) Sensor 
Circuit Malfunction
S7RS0BA204009
Wiring Diagram
DTC Detecting Condition and Possible Cause
Flow Test Description
Step 1: Check whether malfunction is in outside air temperature sensor.
Step 2: Check outside air temperature sensor input circuit.
Step 3: Check outside air temperature sensor ground circuit (for DTC B1141).
DTC Troubleshooting
I4RS0AA20010-01
[A]: BCM connector viewed from harness side 3. Junction block assembly
1. Outside air temperature sensor 4. Outside air temperature sensor connector
2. BCM
DTC detecting condition Possible cause
DTC B1141 (DTC No. 1141):
Input signal from outside air temperature sensor is higher 
than 4.88 V. • Open in outside air temperature sensor circuit
• Outside air temperature sensor malfunction
• BCM malfunction
DTC B1142 (DTC No. 1142):
Input signal from outside air temperature sensor is lower 
than 0.1 V. • Short in outside air temperature sensor circuit
• Outside air temperature sensor malfunction
• BCM malfunction
Step
Action YesNo
1 Check outside air temperature sensor
1) Turn ignition switch to OFF position.
2) Disconnect connector from outside air temperature 
sensor.
3) Check outside air temperature sensor for resistance  referring to “Outside Air Temperature Sensor Inspection 
(If Equipped) in Section 9C”.
Is it in good condition? Go to Step 2.
Replace outside air 
temperature sensor.  
Page 1423 of 1496
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DTC Troubleshooting
DTC B1157 (No. 1157): Air Bag Deployment Signal InputS7RS0BA204011
Wiring Diagram
Refer to “DTC B1150 (No. 1150): Air Bag Communication Circuit Malfunction”.
DTC Detecting Conditi on and Possible Cause
Flow Test Description
Step 1: Check DTC for SDM.
DTC Troubleshooting Step Action Yes No
1 Check air bag communication circuit
1) Turn ignition switch to OFF position.
2) Disconnect connector from SDM referring to “SDM 
Removal and Installation in Section 8B”.
3) Disconnect connector from junction block assembly.
4) Turn ignition switch to ON position.
5) Measure voltage between “L29-37” terminal of SDM  connector and vehicle body ground.
Is voltage 0 V? Go  to Step 2. Short to power supply in 
air bag communication 
circuit.
2 Check air bag communication circuit
1) Turn ignition switch to OFF position.
2) Connect connectors to junction block assembly.
3) Turn ignition switch to ON position.
4) Measure voltage between “L04-2” terminal of junction 
block assembly connector and vehicle body ground.
Is voltage 4 – 6 V? Go to Step 3.
Short to ground in air 
bag communication 
circuit. If OK, substitute 
a known-good BCM 
(included in junction 
block assembly) and 
recheck.
3 Check air bag communication circuit
1) Measure voltage between “L29-37” terminal of SDM 
connector and vehicle body ground.
Is voltage 4 – 6 V? Substitute a known-
good SDM and recheck.
Open or high resistance 
in air bag 
communication circuit.
DTC detecting condition
Possible cause
Air bag deployment signal is fed from SDM to BCM. • Air bag component parts
• BCM malfunction
StepAction YesNo
1 DTC check of SDM
1) Check DTC stored in SDM re ferring to “DTC Check in 
Section 8B”.
Is DTC B1021 detected? Go to “DTC B1021: 
Front Air Bag Module 
Deployed in Section 
8B”.
Substitute a known-
good BCM (included in 
junction block 
assembly) and recheck.  
Page 1424 of 1496
Downloaded from www.Manualslib.com manuals search engine 10B-21 Body Electrical Control System: 
DTC B1170 (No. 1170): EEPROM Access ErrorS7RS0BA204012
DTC Detecting Condition and Possible Cause
DTC Troubleshooting
NOTE
Before performing steps below, be sure to perform “Body Electrical Control System Check”.
 
1) Ignition switch OFF.
2) Replace BCM.
3) Repeat BCM Check Flow Table.
DTC U0155 (No. 0155): Lost Communication with Instrument Panel Cluster (IPC) Control ModuleS7RS0BA204019
Wiring Diagram
ABS model DTC detecting condition Possible cause
Data write error or check sum error. BCM malfunction
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I7RS0BA20004-01
[A]: BCM connector (viewed from harness side)  1. ECM
[B]: ECM connector (viewed from harness side) 2. TCM (A/T model)
[C]: Combination meter connector (viewed from harness side) 3. BCM
[D]: TCM connector (viewed from harness side) 4. Combination meter
[E]: Keyless start control module connector (viewed from harness side) 5. Keyless start control module (if equipped)
[F]: ABS control module connector (viewed from harness side) 6. ABS control module
7. Data link connector (DLC)  
Page 1426 of 1496
Downloaded from www.Manualslib.com manuals search engine 10B-23 Body Electrical Control System: 
DTC TroubleshootingStep Action YesNo
1 DTC check of BCM
Is DTC U0155 (No. 0155) and DTC U1073 (No. 1073) 
detected together? Go to “DTC U1073 (No. 
1073): Control Module 
Communication Bus 
Off”.Go to Step 2.
2 Control module connector check
1) Check connection of connectors of all control modules 
communicating by means of CAN.
2) Recheck BCM for DTC.
Is DTC U0155 (No. 0155) detected? Go to Step 3.
Intermittent trouble.
Check for intermittent 
referring to “Intermittent 
and Poor Connection 
Inspection in Section 
00”.
3 Combination meter power and ground circuit check
1) Turn ignition switch to ON position.
Do warning lights in combi nation meter other than key 
indicator light light up? Go to Step 4.
Check combination 
meter power and 
ground circuit. If circuit 
is OK, substitute a 
known-good 
combination meter and 
recheck.
4 CAN communication circuit check
1) Turn ignition switch to OFF position.
2) Disconnect connectors from BCM, combination meter 
and steering angle sensor (ESP ® model).
3) Check CAN communication circuit between BCM and  combination meter for open, short and high resistance.
Is each CAN communication circuit in good condition? Go to Step 5.
Repair circuit.
5 CAN communication circuit check
1) Disconnect connectors of all control modules 
communicating by means of CAN.
2) Check CAN communication circuit between control  modules other than Step 4 for open, short and high 
resistance.
Is each CAN communication circuit in good condition? Go to Step 6.
Repair circuit.
6 DTC check of BCM
1) Connect connectors of disconnected control modules 
communicating by means of CAN.
2) Disconnect connector of any one of control module other  than BCM.
3) Recheck BCM for DTC.
Is DTC U0155 (No.0155) detected? Disconnect connectors 
of control modules other 
than the one whose 
connector is 
disconnected in Step 2) 
one by one and check 
that DTC U0155 is 
detected by BCM each 
time connector is 
disconnected. When 
DTC U0155 is not 
detected by BCM while 
checking in this way, go 
to description under 
“NO” below. If DTC 
U0155 is detected by 
BCM even when 
connectors of all control 
modules that use CAN 
communication with 
BCM are disconnected, 
substitute a known-
good BCM and recheck.Check power and 
ground circuit of control 
module disconnected in 
Step 2). If circuit is OK, 
substitute a known-
good control module 
disconnected in Step 2) 
and recheck.  
Page 1427 of 1496
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DTC U1073 (No. 1073): Control Module Communication Bus OffS7RS0BA204014
Wiring Diagram
Refer to “DTC U0155 (No. 0155): Lost Communication with Instrument Panel Cluster (IPC) Control Module”.
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure 1) Connect scan tool to DLC with  ignition switch turned OFF.
2) Turn ON ignition switch and clear DTC by using scan tool.
3) Start engine and run it for 1 min. or more.
4) Check DTC.
DTC Troubleshooting DTC detecting condition Trouble area
Transmission error that is inconsistent between transmission data and 
transmission monitor (CAN bus monitor)  data is detected more than 7 
times continuously.
(1 driving detection logic) • CAN communication circuit
• Combination meter
• BCM (included in junction block 
assembly)
• TCM (A/T model)
• ABS/ESP ® control module
• Keyless start control module (if equipped)
•ECM
• Steering angle sensor (if equipped)
Step Action YesNo
1 Control module connector check
1) Check connection of connectors of all control modules 
communicating by means of CAN.
2) Recheck DTC.
Is DTC U1073 detected? Go to Step 2.
Intermittent trouble. 
Check for intermittent 
referring to “Intermittent 
and Poor Connection 
Inspection in Section 
00”.
2 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 3.
Repair circuit.  
Page 1429 of 1496
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DTC TroubleshootingStep Action Yes No 1 DTC check of BCM
Is DTC U1100 (No. 1100) and DTC U1073 (No. 1073) 
detected together? Go to “DTC U1073 (No. 
1073): Control Module 
Communication Bus 
Off”.Go to Step 2.
2 DTC check of ECM
1) Check ECM for DTC.
Is DTC P1674 detected? Go to “DTC P1674: 
CAN Communication 
(Bus Off Error) in 
Section 1A”.Go to Step 3.
3 DTC check of ABS/ESP ® control module
1) Check ABS/ESP ® control module for DTC.
Is DTC U1073 detected? Go to “DTC U1073: 
Control Module 
Communication Bus Off 
in Section 4E” or “DTC 
U1073: Control Module 
Communication Bus Off 
in Section 4F”.Go to Step 4.
4 Control module connector check
1) Check connection of connectors of all control modules 
communicating by means of CAN.
2) Recheck BCM for DTC.
Is DTC U1100 (No. 1100) detected? Go to Step 5. Intermittent trouble. 
Check for intermittent 
referring to “Intermittent 
and Poor Connection 
Inspection in Section 
00”.
5 DTC check of ABS/ESP ® control module
1) Check DTC for ABS/ESP ® control module.
Is DTC U1100 detected? Go to Step 6. Go to Step 7.
6 CAN communication circuit check
1) Disconnect connector s from ECM and ABS/ESP ® 
control module.
2) Check CAN communication circuit between ECM and  ABS/ESP ® control module for open, short and high 
resistance.
Is each CAN communication circuit in good condition? Check ECM power and 
ground circuit. If circuit 
is OK, substitute a 
known-good ECM and 
recheck.
Repair circuit.
7 CAN communication circuit check
1) Disconnect connector s from BCM and ABS/ESP ® 
control module.
2) Check CAN communication circuit between BCM and  ABS/ESP ® control module for open, short and high 
resistance.
Is each CAN communication circuit in good condition? Go to Step 8. Repair circuit.
8 CAN communication circuit check
1) Disconnect connectors of all control modules 
communicating by means of CAN.
2) Check CAN communication circuit between control  modules other than Step 7 for open, short and high 
resistance.
Is each CAN communication circuit in good condition? Go to Step 9. Repair circuit.