Suzuki Grand Vitara JB627. Manual - part 161

3C-48 Transfer: 

DTC U1100: Lost Communication with ECM

S6JB0B3304027

Wiring Diagram
Refer to “DTC U1073: Control Module Communication Bus Off”.

DTC Detecting Condition and Trouble Area

DTC Confirmation Procedure

1) Clear DTC using scan tool.
2) Start engine and run it for 1 min. or more.
3) Stop vehicle and check DTC.

Troubleshooting

DTC detecting condition

Trouble area

Reception error of communication data for ECM is detected for 
longer than specified time continuously.

• CAN communication circuit
• ABS or ESP

® hydraulic unit / control module

• ECM
• 4WD control module

Step

Action

Yes

No

1

Was “4WD control system check” performed?

Go to Step 2.

Go to “4WD Control 
System Check”.

2

DTC check
1) Check DTC in 4WD control module.

Is DTC U1100 and DTC U1073 detected together?

Go to “DTC U1073: 
Control Module 
Communication Bus 
Off”.

Go to Step 3.

3

DTC check
1) Check DTC in ECM.

Is DTC P1674 detected?

 Go to “DTC U0073: 
Control Module 
Communication Bus Off 
in Section 1A”.

Go to Step 4.

4

Check each control module connectors
1) Check connection of connectors of all control modules 

communicating by means of CAN.

2) Recheck in 4WD control module.

 Is DTC U1100 detected?

Go to Step 5.

NO    Intermittent 
trouble. Check for 
intermittent referring to 
“Intermittent and Poor 
Connection Inspection 
in Section 00”.

5

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 ECM power and 
ground circuit. If circuit 
is OK, substitute a 
known-good ECM and 
recheck.

Repair circuit.

Transfer: 3C-49

DTC U1101: Lost Communication with TCM

S6JB0B3304028

Wiring Diagram
Refer to “DTC U1073: Control Module Communication Bus Off”.

DTC Detecting Condition and Trouble Area

DTC Confirmation Procedure

1) Clear DTC using scan tool.
2) Start engine and run it for 1 min. or more.
3) Stop vehicle and check DTC.

Troubleshooting

DTC detecting condition

Trouble area

Reception error of communication data for TCM is detected for 
longer than specified time continuously.

• CAN communication circuit
• TCM
• 4WD control module

Step

Action

Yes

No

1

Was “4WD control system check” performed?

Go to Step 2.

Go to “4WD Control 
System Check”.

2

DTC check
1) Check DTC in 4WD control module.

Is DTC U1100 and DTC U1073 detected together?

Go to “DTC U1073: 
Control Module 
Communication Bus 
Off”.

Go to Step 3.

3

DTC check
1) Check DTC in TCM.

Is DTC P1774 detected?

Go to “DTC U0073: 
Control Module 
Communication Bus Off 
in Section 5A”.

Go to Step 4.

4

Check each control module connectors
1) Check connection of connectors of all control modules 

communicating by means of CAN.

2) Recheck in 4WD control module.

Is DTC U1100 detected?

Go to Step 5.

Intermittent trouble. 
Check for intermittent 
referring to “Intermittent 
and Poor Connection 
Inspection in Section 
00”.

5

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.

3C-50 Transfer: 

DTC U1121: Lost Communication with ABS / Electronic Stability Program Hydraulic Unit / Control 
Module

S6JB0B3304029

Wiring Diagram
Refer to “DTC U1073: Control Module Communication Bus Off”.

DTC Detecting Condition and Trouble Area

DTC Confirmation Procedure

1) Clear DTC using scan tool.
2) Start engine and run it for 1 min. or more.
3) Stop vehicle and check DTC.

Troubleshooting

Inspection of 4WD Control Module and Its Circuits

S6JB0B3304030

4WD control module and its circuits can be checked at coupler connected to 4WD control module by measuring 
voltage, pulse signal.

CAUTION

!

 

4WD control module cannot be checked by itself. It is strictly prohibited to connect voltmeter or 
ohmmeter to 4WD control module with couplers disconnected from it.

 

DTC detecting condition

Trouble area

Reception error of communication data for ABS or ESP

® 

hydraulic unit / control module is detected for longer than 
specified time continuously.

• CAN communication circuit
• ABS or ESP

® hydraulic unit / control module

• 4WD control module

Step

Action

Yes

No

1

Was “4WD control system check” performed?

Go to Step 2.

Go to “4WD Control 
System Check”.

2

DTC check
1) Check DTC in 4WD control module.

Is DTC U1100 and DTC U1073 detected together?

Go to “DTC U1073: 
Control Module 
Communication Bus 
Off”.

Go to Step 3.

3

DTC check
1) Check DTC in ABS or ESP

® hydraulic unit / control 

module.

Is DTC PU1073 detected?

Go to “DTC U1073: 
Control Module 
Communication Bus Off 
in Section 4E”.

Go to Step 4.

4

Check each control module connectors
1) Check connection of connectors of all control modules 

communicating by means of CAN.

2) Recheck in 4WD control module.

Is DTC U1100 detected?

Go to Step 5.

Intermittent trouble. 
Check for intermittent 
referring to “Intermittent 
and Poor Connection 
Inspection in Section 
00”.

5

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 ABS or ESP

® 

hydraulic unit / control 
module power and 
ground circuit. If circuit 
is OK, substitute a 
known-good ABS or 
ESP

® hydraulic unit / 

control module and 
recheck.

Repair circuit.

Transfer: 3C-51

Voltage and Signal Check

1) Check voltage using voltmeter (1) connected to each terminal of couplers.
2) Check signal using oscilloscope (2) connected to each terminal of couplers.

NOTE

• As each terminal voltage is affected by the battery voltage, confirm that it is 11 V or more when 

ignition switch is turned ON.

• Pulse signal cannot be measured by voltmeter. It can be measured by oscilloscope.
• Item with asterisk (*) in normal voltage column can be read only by oscilloscope.

 

Terminal arrangement of 4WD control module connector (Viewed from harness side)

1

2

I4JA01332053-01

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

I4JA01332054-01

Terminal 

Number

Wire 

Color

Circuit

Normal 

Voltage

Condition

E91-1

BLK

Ground

0 – 1 V

—

E91-2

BLU

Transfer actuator 
motor 1

10 – 14 V

Ignition switch turned to ON position and transfer shift 
actuator being rotated N 

→ 4H → 4H-lock direction or 4L-

lock 

→ 4H-lock direction

0 – 1 V

Ignition switch turned to ON position and transfer shift 
actuator in other than above-mentioned condition

E91-3

YEL

Transfer actuator 
motor 2

10 – 14 V

Ignition switch turned to ON position and transfer shift 
actuator being rotated 4H-lock 

→ 4H → N direction or 

4H-lock 

→ 4L-lock direction

0 – 1 V

Ignition switch turned to ON position and transfer shift 
actuator in other than above-mentioned condition

E91-4

—

—

—

—

E91-5

—

—

—

—

E91-6

—

—

—

—

E91-7

BLK/ORN Clutch switch

10 – 14 V

Ignition switch turned to ON position and clutch pedal 
released

0 – 1 V

Ignition switch turned to ON position and clutch pedal 
kept depressing

E91-8

PNK

Diagnosis switch

4 – 5 V

Ignition switch turned to ON position