P1674 SUZUKI SWIFT 2007 2.G Service User Guide
Page 566 of 1496
Downloaded from www.Manualslib.com manuals search engine 4E-27 ABS: 
DTC U1100: Lost Communication with ECM (Reception Error)S7RS0B4504019
Wiring Diagram
Refer to “DTC U1073: Control Module Communication Bus Off”.
DTC Detecting Condition
Reception error of communication data for ECM is detected more than specified time continuously.
DTC Troubleshooting Step Action Yes No 1 Was “ABS Check” performed? Go to Step 2. Go to “ABS Check”.
2 1) Check DTC for ABS.
Is DTC U1073 detected? Go to “DTC U1073: 
Control Module 
Communication Bus 
Off”.Go to Step 3.
3 1) Check DTC for ECM. Is DTC P1674 detected? Go to “DTC P1674: 
CAN Communication 
(Bus Off Error) in 
Section 1A”.Go to Step 4.
4 1) Check connection of connectors of all control modules  communicating by means of CAN.
2) Check DTC for ABS.
Is DTC U1100 detected? Go to Step 5. Intermittent trouble.
Check for intermittent 
referring to “Intermittent 
and Poor Connection 
Inspection in Section 
00” in related manual.
5 1) Turn ignition switch to OFF position.
2) Disconnect connectors of  ABS control module and ECM 
communicating by means of CAN.
3) Check CAN communication circuit between ABS control  module and ECM for open, short and high resistance.
Is CAN communication circuit in good condition? Go to Step 6. Repair or replace the 
CAN communication 
line.
6 1) Disconnect connectors of all control modules  communicating by means of CAN.
2) Check CAN communication circuit between control  modules other than Step 5 for open, short and high 
resistance.
Is each CAn communication circuit in good condition? Go to Step 7. Repair or replace the 
CAN communication 
line.
7 1) Turn ignition switch to OFF position. 2) Connect connector of disconnected control modules communicating by means of CAN.
3) Disconnect connector from any one of control modules  other than BCM and ABS control module.
4) Recheck ABS contro l module for DTC
IS DTC U1100 detected? Disconnected 
connectors of control 
modules other than the 
one whose connector is 
disconnected in Step 3) 
one by one and check 
that DTC U1100 is 
detected by ABS control 
module each time 
connector is 
disconnected.
When DTC U1100 is not 
detected by ABS 
module while checking 
in this way, go to 
description under “NO” 
below. If DTC U1100 is 
detected by ABS control 
module, go to Step 8.Check power and 
ground circuit of control 
module disconnected in 
Step 3) circuit is OK, 
substitute a know-good 
control module 
disconnected in Step 3) 
and recheck.  
Page 621 of 1496
Downloaded from www.Manualslib.com manuals search engine Electronic Stability Program:  4F-47
DTC Troubleshooting
DTC C1090: Invalid Communication with ECMS7RS0B4604040
DTC Detecting Condition and Trouble Area
DTC TroubleshootingStep Action Yes No
1 Was “Electronic Stability Pr ogram Check” performed? Go to Step 2. Go to “Electronic 
Stability Program 
System Check”.
2 DTC check for ESP®
1) Connect scan tool to DLC with ignition switch turned 
OFF.
2) Turn ignition switch ON and check DTC for ESP ®.
Is there any DTC(s) other than C1075, C1076 and C1078? Go to applicable DTC 
diag. flow.
Go to Step 3.
3 Check sensor calibration
1) Calibrate all sens ors referring to “Sensor Calibration”.
2) Clear all DTC(s) and check DTC for ESP ®.
Is DTC C1075, C1076 and/ or C1078 still detected? DTC C1075: Substitute 
a known-good steering 
angle sensor and 
recheck.
DTC C1076: Substitute 
a known-good ESP
® 
hydraulic unit / control 
module assembly and 
recheck.
DTC C1078: Substitute 
a known-good yaw rate 
/ G sensor assembly 
and recheck. Calibration was 
incompleted.
DTC Detecting Condition
Trouble Area
ESP ® control module rolling counte r failure is detected by 
ECM. • CAN communication circuit
•ECM
• ESP
® control module
Step Action YesNo
1 Was “Electronic Stability Pr ogram Check” performed? Go to Step 2.Go to “Electronic 
Stability Program 
System Check”.
2 DTC check for ESP®
1) Connect scan tool to DLC with ignition switch turned 
OFF.
2) Turn ignition switch ON and check DTC for ESP ®.
Is there any DTC(s) other than C1038 and C1090? Go to applicable DTC 
diag. flow.
Go to Step 3.
3 DTC check for ECM
1) Check DTC for ECM.
Is DTC P1674 and/or DTC P1685 detected? Go to applicable DTC 
diag. flow.
Substitute a known-
good ESP
® hydraulic 
unit / control module 
assembly and recheck.  
Page 624 of 1496
Downloaded from www.Manualslib.com manuals search engine 4F-50 Electronic Stability Program: 
DTC Troubleshooting
DTC U1100: Lost Communication with ECM (Reception Error)S7RS0B4604058
Wiring Diagram
Refer to “Wiring Diagram” under “DTC U1073: Control Module Communication Bus Off”.
DTC Detecting Condition and Trouble Area
DTC TroubleshootingStep Action Yes No
1 Was “Electronic Stability Pr ogram Check” performed? Go to Step 2. Go to “Electronic 
Stability Program 
System Check”.
2 DTC check for ESP®
1) Check connection of connectors of all control modules 
communicating by means of CAN.
2) Recheck DTC for ESP ®.
Is DTC U1073 indicated? 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 or replace the 
CAN communication 
line.
4 DTC check for ESP®
1) Connect connectors of disconnected control modules 
communicating by means of CAN.
2) Disconnect each connector. •ECM
• Keyless start control module (if equipped)
• Combination meter
• Steering angle sensor
•BCM
3) Recheck DTC for ESP ®.
Is DTC U1073 detected? Check ESP
® control 
module power and 
ground circuit. If circuits 
are OK, substitute a 
known-good ESP ® 
hydraulic unit / control 
module assembly and 
recheck. Check applicable 
control module power 
and ground circuit. If 
circuit is OK, substitute 
a known-good 
applicable control 
module and recheck.
DTC Detecting Condition
Trouble Area
ECM message data is missing from CAN communication. • CAN communication circuit
•ECM
• ESP® control module
Step Action YesNo
1 Was “Electronic Stability Pr ogram Check” performed? Go to Step 2.Go to “Electronic 
Stability Program 
System Check”.
2 DTC check for ESP®
1) Check DTC for ESP ®.
Is DTC U1100 and DTC U1073 detected together? Go to “DTC U1073: 
Control Module 
Communication Bus 
Off”.Go to Step 3.
3 DTC check for ECM
1) Check DTC for ECM.
Is DTC P1674 detected? Go to “DTC P1674: 
CAN Communication 
(Bus Off Error) in 
Section 1A”.Go to Step 4.  
Page 717 of 1496
Downloaded from www.Manualslib.com manuals search engine Automatic Transmission/Transaxle:  5A-73
DTC P1777: TCM Lost Communication with ECM (Reception Error)S7RS0B5104040
Wiring Diagram
Refer to “DTC P1774: CAN Communication Bus Off”
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure1) 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:” and confirm 
that the trouble has been corrected.
 
DTC detecting condition Trouble area
Reception error of communication data fo r ECM is detected more than specified 
time continuously. •ECM
•TCM
• 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 of CAN.
2) Recheck DTC.
Is there DTC P1777? Go to Step 3.
Intermittent trouble. 
Check for intermittent 
referring to “Intermittent 
and Poor Connection 
Inspection in Section 
00”.
3 DTC check
1) Check ECM for DTC referring to “DTC Check in Section 
1A”.
Is there DTC P1674? Go to “DTC P1674: 
CAN Communication 
(Bus Off Error) in 
Section 1A”.
Check ECM power and 
ground circuit. If circuit 
is OK, CAN 
communication circuit 
between ECM and ABS 
hydraulic unit / control 
module is open circuit.
4 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.  
Page 1429 of 1496
Downloaded from www.Manualslib.com manuals search engine Body Electrical Control System:  10B-26
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.  
Page 1430 of 1496
Downloaded from www.Manualslib.com manuals search engine 10B-27 Body Electrical Control System: 
DTC U1101 (No. 1101): Lost Communication with TCMS7RS0BA204016
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 9
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 U1100 (No.1100) detected? Disconnect connectors 
of control modules other 
than the one whose 
connector is 
disconnected in Step 2) 
one by one and check 
that DTC U1100 is 
detected by BCM each 
time connector is 
disconnected. When 
DTC U1100 is not 
detected by BCM while 
checking in this way, go 
to description under 
“NO” below. If DTC 
U1100 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.
Step Action Yes No
DTC detecting condition
Trouble area
BCM can not receive CAN data from TCM for longer than specified 
time continuously. • CAN communication circuit
• BCM (included in junction block assembly)
• TCM (A/T model)
Step
Action YesNo
1 DTC check of BCM
Is DTC U1101 (No. 1101) 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 TCM
1) Check TCM for DTC.
Is DTC P1774 detected? Go to “DTC P1774: 
CAN Communication 
Bus Off in Section 5A”.
Go to Step 3.
3 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 4.  
Page 1450 of 1496
Downloaded from www.Manualslib.com manuals search engine 10C-7 Immobilizer Control System: 
Scan Tool DataS7RS0BA304005
Scan Tool Data Definitions
NUMBER OF LEARNT KEY
0 – 4 PCS:  The number of the transponder code in the transponder  built in the ignition key that is registered with ECM
NOTE
A maximum of four transponder codes can be registered with ECM. Therefore, the maximal value 
should be 4.
 
INPUT YEAR
20**:  The year in which the transponder code in the transpon der built in the ignition key is registered with ECM
INPUT MONTH
1 – 12:   The month in which the transponder code in the transpond er built in the ignition key is registered with ECM
Immobilizer Indicator Lamp Does Not Come ON with Ignition Switch ON and Engine StopS7RS0BA304006
Wiring Diagram
Refer to “Immobilizer Control System Wiring Circuit Diagram”.
Circuit Description
When the ignition switch is turned ON, ECM read the code by  the coil antenna from ignition key. Then if the code in 
transponder in the key match with the one  registered with ECM, transmits indication ON signal of immobilizer indicator 
lamp to combination meter in order to turn immobilizer indicator lamp on. And then, combination meter turns 
immobilizer indicator lamp on. When th e engine starts to run and no malfunction is detected in the system, ECM 
transmits immobilizer indi cator lamp indication OFF signal to combination  meter in order to turn immobilizer indicator 
lamp off. And then, comb ination meter turns immobilizer indicator lamp off, but if  a malfunction was or is detected, 
immobilizer indicator lamp is flashes ON and OF F, when ignition switch turn to ON position.
Troubleshooting Scan Tool Data Vehicl
e Condition Normal Data
NUMBER OF LEARNT KEY Ignition switch at ON position 0 – 4 INPUT YEAR Ignition switch at  ON position 2005 or later
INPUT MONTH Ignition switch at ON position 1 – 12
Step Action YesNo
1 Immobilizer indicator lamp power supply check
1) Turn ignition switch to ON position.
Do other warning lights come ON? Go to Step 2.
Go to Step 4.
2 DTC check of ECM
1) Connect scan tool to DLC with ignition switch turned 
OFF.
2) Turn ON ignition switch and check DTC.
Is DTC P1674, P1675, P1678 and/or P1685 detected? Go to applicable DTC 
diag. flow.
Go to Step 3.
3 DTC check of BCM
1) Check BCM for DTC referring to “DTC Check in Section 
10B”.
Is DTC U1073, U1100 and/or U1144 detected? Go to applicable DTC 
diag. flow.
Substitute a known-
good combination meter 
and recheck. If 
immobilizer indicator 
lamp still remains OFF, 
substitute a known good 
ECM and recheck.  
Page 1451 of 1496
Downloaded from www.Manualslib.com manuals search engine Immobilizer Control System:  10C-8
Immobilizer Indicator Lamp Remains ON after Engine StartsS7RS0BA304007
Wiring Diagram
Refer to “Immobilizer Control S ystem Wiring Circuit Diagram”.
Circuit Description
When the ignition switch is turned ON, ECM read the code by  the coil antenna from ignition key. Then if the code in 
transponder in the key match with the one  registered with ECM, transmits indication ON signal of immobilizer indicator 
lamp to combination meter in order to turn immobilizer indicator lamp on. And then, combination meter turns 
immobilizer indicator lamp on. When th e engine starts to run and no malfunction is detected in the system, ECM 
transmits immobilizer indicator lamp indication O FF signal to combination meter in order to turn immobilizer indicator 
lamp off. And then, comb ination meter turns immobilizer indicator lamp off, but if  a malfunction was or is detected, 
immobilizer indicator lamp is flashes ON and OF F, when ignition switch turn to ON position.
Troubleshooting 4
Fuse check
1) Turn ignition switch to OFF position.
2) Check for fuse blown at combination meter circuit fuse in 
junction block assembly.
Is fuse in good condition? Go to Step 5. Replace fuse and check 
for short to power or 
ground 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 for open, short and high resistance.
Is each CAN communication circuit in good condition? Go to Step 6. Repair circuit.
6 Combination meter power and ground circuit check
1) Remove combination meter referring to “Combination 
Meter Removal and Installation in Section 9C”.
2) Check for proper connection to combination meter  connector terminals.
3) If OK, then turn ignition switch to ON position, Check  terminal voltage of combination meter between power 
supply and ground terminal. Refer to “Combination 
Meter Circuit Diagram in Section 9C”.
Is it 10 – 14 V? Substitute a known-
good combination meter 
and recheck. If 
immobilizer indicator 
lamp still remains OFF, 
substitute a known good 
ECM and recheck.
Repair power supply 
and/or ground circuit.
Step Action Yes No
Step
Action YesNo
1 DTC check of ECM
1) Start engine and recheck DTC of ECM while engine 
running.
Is DTC P1674, P1675, P1678 and/or P1685 detected? Go to applicable DTC 
diag. flow.
Go to Step 2.
2 CAN communication circuit check
1) Disconnect connectors from  ECM, BCM, ABS control 
module and combination meter.
2) Check CAN communication circuit for open, short and  high resistance.
• Between ECM and ABS control module
• Between BCM and ABS control module
• Between BCM and combination meter
Is each CAN communication circuit in good condition? Substitute a known-
good combination meter 
and recheck. If 
immobilizer indicator 
lamp still remains ON, 
substitute a known-
good ECM and recheck.
Repair circuit.  
Page 1454 of 1496
Downloaded from www.Manualslib.com manuals search engine 10C-11 Immobilizer Control System: 
Detecting Condition and Trouble Area
DTC Confirmation Procedure1) Engine start knob turn to ON position.
2) Check DTC for ECM.
Troubleshooting
DTC P1618: CAN Communication Error (Reception Error for Keyless Start Control Module) (Vehicle 
equipped with keyless start system only)
S7RS0BA304011
Detecting Condition and Trouble Area
DTC Confirmation Procedure 1) Turn Ignition switch to ON position.
2) Check DTC for ECM.
Troubleshooting Detecting Condition Trouble Area
ECM detects different ID codes registered in ECM and 
keyless start control module. • Keyless start control module
•ECM
Step
Action YesNo
1 Was “Immobilizer Control S ystem Check” performed? Go to Step 2.Go to “Immobilizer 
Control System Check”.
2 Registration of the Ignition Key
1) Clear DTC referring to “Diagnostic Trouble Code (DTC) 
Clearance”.
2) Register ignition key with ECM referring to “Registration  of the Ignition Key”.
Is ignition key able to be registered? Go to Step 3.
Go to Step 4.
3 Keyless start system operation check
Engine start using keyless start system.
Does engine start? Unregistration of remote 
controller ID code.
Check DTC for ECM. 
When DTC is detected, 
go to applicable DTC.
4 DTC check of ECM
Check DTC for ECM.
Is DTC P1618 and/or P1615 detected other than P1616? Go to DTC P1618 
troubleshooting.
Go to DTC P1615 
troubleshooting.
Detecting Condition
Trouble Area
Reception error of communication data for keyless start 
control module is detected for longer than specified time 
continuously. • CAN communication circuit
• Combination meter
• Keyless start control module
•BCM
•ECM
• ABS/ESP®
 control module
Step Action YesNo
1 Was “Immobilizer Control S ystem Check” performed? Go to Step 2.Go to “Immobilizer 
Control System Check”.
2 DTC check of ECM
Is DTC P1674, P1675, P1678 and/or P1685 detected 
together? Go to applicable DTC 
diag. flow.
Go to Step 3.  
Page 1457 of 1496
Downloaded from www.Manualslib.com manuals search engine Immobilizer Control System:  10C-14
DTC P1625: Immobilizer Antenna ErrorS7RS0BA304015
Detecting Condition and Trouble Area
DTC Confirmation Procedure1) Turn ignition switch to ON position.
2) Check DTC in ECM.
Troubleshooting
DTC P1636: Immobilizer Information Registration FailureS7RS0BA304016
DTC Detecting Condition and Trouble Area
Troubleshooting 3
Registration of unregistered ignition key with ECM
1) Register unregistered igniti on key with ECM referring to 
“Registration of the Ignition Key”.
Was registration of ignition key completed? Unregistered ignition 
key.
Go to Step 4.
4 Registration of the spare ignition key
1) Register the spare ignition key referring to “Registration 
of the Ignition Key”.
Was registration of spare ignition key completed? Replace ignition key 
which cannot be 
registered.
Substitute a known-
good ECM and recheck.
Step Action Yes No
Detecting Condition
Trouble Area
ICM • ICM
•ECM
StepAction YesNo
1 Was “Immobilizer Control S ystem Check” performed? Go to Step 2.Go to “Immobilizer 
Control System Check”.
2 DTC confirmation
1) Clear DTC(s) referring to “Diagnostic Trouble Code 
(DTC) Clearance”.
2) Turn the ignition switch to OFF position.
3) Check ECM for DTC referring to “Diagnostic Trouble  Code (DTC) Check”.
Is DTC P1625 still detected? Replace ICM and 
recheck DTC. If DTC 
P1625 is still detected, 
substitute a known-
good ECM and recheck.
Intermittent trouble. 
Check for intermittent 
referring to “Intermittent 
and Poor Connection 
Inspection in Section 
00”.
Detecting Condition
Trouble Area
The registration  of the immobilizer control system 
information in ECM is failed. • CAN communication wire circuits
•BCM
•ECM
Step
Action YesNo
1 Was “Immobilizer Control S ystem Check” performed? Go to Step 2.Go to “Immobilizer 
Control System Check”.
2 DTC check of ECM
1) Check ECM for DTC referring to “DTC Check in Section 
1A”.
Is DTC P1674, P1675, P1678 and/or P1685 detected? Go to applicable DTC 
diag. flow.
Go to Step 3.