Suzuki GSX-R1000. Service Manual - part 10

1A-82 Engine General Information and Diagnosis: 

Step

Action

Yes

No

1

7) Check the continuity between the Y/W wire and terminal 

“18”. Also, check the continuity between the B/Br wire 
and terminal “35”.

Special tool

(A):  09900–25008 (Multi circuit tester set)
(B):  09900–25009 (Needle-point probe set)

Tester knob indication
Continuity test (

)

ECM couplers (Harness side)

Is the continuity OK?

Go to Step 3.

Y/W wire shorted to 
VCC, or B/Br wire open.

(Black)

(Gray)

?

“18”

“35”

(A)

(B)

I947H1110048-02

Engine General Information and Diagnosis:  1A-83

P1654-L (Use of SDS)

Step

Action

Yes

No

1

1) Turn the ignition switch OFF.

2) Lift and support the fuel tank. Refer to “Fuel Tank 

Removal and Installation” in Section 1G (Page 1G-9).

3) Check the STP sensor couplers (1) and (2) for loose or 

poor contacts.
If OK, then check the STP sensor lead wire continuity.

4) Disconnect the STP sensor couplers (1) and (2).

5) Check the continuity between the Y/W wire and ground. 

Also, check the continuity between the Y/W wire and B/
Br wire.
If the sound is not heard from the tester, the circuit 
condition is OK.

Special tool

(A):  09900–25008 (Multi circuit tester set)

Tester knob indication
Continuity test (

)

6) Disconnect the ECM couplers. Refer to “ECM Removal 

and Installation” in Section 1C (Page 1C-1).

Go to Step 2.

R or Y/W wire open, or 
Y/W wire shorted to 
ground.

1

2

I947H1110054-01

(A)

I947H1110049-01

1A-84 Engine General Information and Diagnosis: 

Step

Action

Yes

No

1

7) Check the continuity between the Y/W wire and terminal 

“18”. Also, check the continuity between the R wire and 
terminal “7”.

Special tool

(A):  09900–25008 (Multi circuit tester set)
(B):  09900–25009 (Needle-point probe set)

Tester knob indication
Continuity test (

)

ECM couplers (Harness side)

Is the continuity OK?

Go to Step 2.

R or Y/W wire open, or 
Y/W wire shorted to 
ground.

2

1) Connect the ECM couplers.

2) Turn the ignition switch ON.

3) Measure the input voltage between the R wire and 

ground. Also, measure the input voltage between the R 
wire and B/Br wire.

Special tool

(A):  09900–25008 (Multi circuit tester set)

Tester knob indication
Voltage (

)

STP sensor input voltage
4.5 – 5.5 V
((+) terminal: R – (–) terminal: Ground, (+) terminal: R 
– (–) terminal: B/Br)

Is the voltage OK?

Go to Step 3.

Open or short circuit in 
the R or B/Br wire.

(Black)

(Gray)

?

(B)

(A)

“7”

“18”

I947H1110050-01

V

(A)

I947H1110051-01

Engine General Information and Diagnosis:  1A-85

3

1) Turn the ignition switch OFF.

2) Connect the ECM couplers and STP sensor couplers.

3) Remove the air cleaner box cover. Refer to “Air Cleaner 

Element Removal and Installation” in Section 1D 
(Page 1D-6).

4) Disconnect the STVA lead wire coupler (1).

5) Insert the needle point probes to the lead wire coupler.

6) Turn the ignition switch ON.

7) Measure the STP sensor output voltage at the coupler 

(between the Y/W wire (+) and B/Br wire (–)) by turning 
the secondary throttle valve (close and open) with your 
finger.

Special tool

(A):  09900–25008 (Multi circuit tester set)
(B):  09900–25009 (Needle-point probe set)

Tester knob indication
Voltage (

)

STP sensor output voltage
Secondary throttle valve is closed: Approx. 0.7 V
Secondary throttle valve is opened: Approx. 4.1 V
((+) terminal: Y/W – (–) terminal: B/Br)

Is the voltage OK?

• R, Y/W or B/Br wire 

open or shorted to 
ground, or poor “7”, 
“18” or “35” 
connection.

• If wire and 

connection are OK, 
intermittent trouble or 
faulty ECM.

• Recheck each 

terminal and wire 
harness for open 
circuit and poor 
connection.

• Replace the ECM 

with a known good 
one, and inspect it 
again. Refer to “ECM 
Removal and 
Installation” in 
Section 1C 
(Page 1C-1).

If check result is not 
satisfactory, replace the 
STP sensor with a new 
one. Refer to “STP 
Sensor Removal and 
Installation” in Section 
1C (Page 1C-7).

Step

Action

Yes

No

1

I947H1110052-01

V

(A)

(B)

I947H1110053-01

I705H1110071-01

1A-86 Engine General Information and Diagnosis: 

DTC “C31” (P0705): GP Switch Circuit Malfunction

B947H11104021

Detected Condition and Possible Cause

Wiring Diagram

ECM coupler (Harness side)

Troubleshooting

CAUTION

!

 

When using the multi-circuit tester, do not strongly touch the terminal of the ECM coupler with a 
needle pointed tester probe to prevent terminal damage.

 

NOTE

After repairing the trouble, clear the DTC using SDS tool. Refer to “Use of SDS Diagnosis Reset 
Procedures” (Page 1A-14).

 

Detected Condition

Possible Cause

No Gear Position switch voltage
GP switch voltage is not within the following range.
GP switch voltage > 0.6 V

• GP switch circuit open or short.

• GP switch malfunction.

• ECM malfunction.

N

1

5

4

2

3

ECM

GP

E1

6

B/W

P

Bl

P

B/W

GP switch

Side-stand relay

Neutral indicator light

Side-stand switch

Ignition
switch

To the engine stop switch

22

36

I837H1110067-01

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 27 28 29 30 31 32 33 34 35 36

37 38 39 40 41 42 43 44 45 46 47 48

49 50 51 52 53 54 55 56 57 58 59 60

61 62 63 64 65 66 67 68 69 70 71 72

I837H1110007-02

Engine General Information and Diagnosis:  1A-87

Step

Action

Yes

No

1

1) Turn the ignition switch OFF.

2) Lift and support the fuel tank. Refer to “Fuel Tank 

Removal and Installation” in Section 1G (Page 1G-9).

3) Check the GP switch coupler (1) for loose or poor 

contacts.
If OK, then measure the GP switch voltage.

4) Support the motorcycle with a jack.

5) Fold the side-stand to up position.

6) Make sure the engine stop switch is in the “RUN” 

position.

7) Insert the needle pointed probe to the lead wire coupler.

8) Turn the ignition switch ON.

9) Measure the voltage between the P and B/W wire, when 

shifting the gearshift lever from 1st to Top.

Special tool

(A):  09900–25008 (Multi circuit tester set)
(B):  09900–25009 (Needle-point probe set)

Tester knob indication
Voltage (

)

GP switch voltage
0.6 V and more
((+) terminal: P – (–) terminal: B/W)

Is the voltage OK?

• P wire open or 

shorted to ground.

• If wire and 

connection are OK, 
intermittent trouble or 
faulty ECM.

• Recheck each 

terminal and wire 
harness for open 
circuit and poor 
connection.

• Replace the ECM 

with a known good 
one, and inspect it 
again. Refer to “ECM 
Removal and 
Installation” in 
Section 1C 
(Page 1C-1).

• P or B/W wire open, 

or P wire shorted to 
ground.

• Loose or poor 

contacts on the ECM 
coupler.

• If wire and 

connection are OK, 
replace the GP 
switch with a new 
one. Refer to “Gear 
Position (GP) Switch 
Removal and 
Installation” in 
Section 5B (Page 5B-
14).

1

I947H1110055-01

V

(A)

(B)

I947H1110056-01

1A-88 Engine General Information and Diagnosis: 

DTC “C32” (P0201), “C33” (P0202), “C34” (P0203) or “C35” (P0204): Primary Fuel Injector Circuit 
Malfunction

B947H11104022

Detected Condition and Possible Cause

Wiring Diagram

ECM coupler (Harness side)

Troubleshooting

CAUTION

!

 

When using the multi-circuit tester, do not strongly touch the terminal of the ECM coupler with a 
needle pointed tester probe to prevent terminal damage.

 

NOTE

After repairing the trouble, clear the DTC using SDS tool. Refer to “Use of SDS Diagnosis Reset 
Procedures” (Page 1A-14).

 

Detected Condition

Possible Cause

CKP signal is produced but fuel injector signal is 
interrupted by 4 times or more continuity.

• Injector circuit open or short.

• Injector malfunction.

• ECM malfunction.

ECM

Fuel pump relay

Primary fuel injector

Y/R

Gr/W

Gr/B

Gr/Y
Gr/R

#21
#31
#41

#11

To engine  
stop switch

#2

#3

#4

#1

46
45
44
43

I837H1110070-02

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 27 28 29 30 31 32 33 34 35 36

37 38 39 40 41 42 43 44 45 46 47 48

49 50 51 52 53 54 55 56 57 58 59 60

61 62 63 64 65 66 67 68 69 70 71 72

I837H1110007-02

Engine General Information and Diagnosis:  1A-89

Step

Action

Yes

No

1

1) Turn the ignition switch OFF.

2) Lift and support the fuel tank. Refer to “Fuel Tank 

Removal and Installation” in Section 1G (Page 1G-9).

3) Check the primary fuel injector coupler (1) for loose or 

poor contacts.
If OK, then measure the injector resistance.

4) Disconnect the injector coupler and measure the 

resistance between terminals.

Special tool

(A):  09900–25008 (Multi circuit tester set)

Tester knob indication
Resistance (

Ω

)

Injector resistance
11 – 13 

Ω

 at 20 

°

C (68 

°

F)

(Terminal – Terminal)

Go to Step 2.

Replace the injector 
with a new one. Refer to 
“Throttle Body 
Disassembly and 
Assembly” in Section 
1D (Page 1D-11).

1

I947H1110057-01

(A)

I947H1110058-01

1A-90 Engine General Information and Diagnosis: 

Step

Action

Yes

No

1

5) If OK, then check the continuity between each terminal 

and ground.

Special tool

(A):  09900–25008 (Multi circuit tester set)

Injector continuity

∞

 

Ω

 (Infinity)

Are the resistance and continuity OK?

Go to Step 2.

Replace the injector 
with a new one. Refer to 
“Throttle Body 
Disassembly and 
Assembly” in Section 
1D (Page 1D-11).

2

1) Turn the ignition switch ON.

2) Measure the injector voltage between the Y/R wire and 

ground.

NOTE

Injector voltage can be detected only for 3 
seconds after ignition switch is turned ON.

 

Special tool

(A):  09900–25008 (Multi circuit tester set)

Tester knob indication
Voltage (

)

Injector voltage
Battery voltage
((+) terminal: Y/R – (–) terminal: Ground)

Is the voltage OK?

• Gr/W wire open or 

shorted to ground, or 
poor “46” connection 
(#1 cylinder side).

• Gr/B wire open or 

shorted to ground, or 
poor “45” connection 
(#2 cylinder side).

• Gr/Y wire open or 

shorted to ground, or 
poor “44” connection 
(#3 cylinder side).

• Gr/R wire open or 

shorted to ground, or 
poor “43” connection 
(#4 cylinder side).

• If wire and 

connection are OK, 
intermittent trouble or 
faulty ECM.

• Recheck each 

terminal and wire 
harness for open 
circuit and poor 
connection.

• Replace the ECM 

with a known good 
one, and inspect it 
again. Refer to “ECM 
Removal and 
Installation” in 
Section 1C 
(Page 1C-1).

Open circuit in the Y/R 
wire.

(A)

I947H1110059-01

(A)

I947H1110060-01

Engine General Information and Diagnosis:  1A-91

DTC “C36” (P1764), “C37” (P1765), “C38” (P1766) or “C39” (P1767): Secondary Fuel Injector Circuit 
Malfunction

B947H11104023

Detected Condition and Possible Cause

Wiring Diagram

ECM coupler (Harness side)

Troubleshooting

CAUTION

!

 

When using the multi-circuit tester, do not strongly touch the terminal of the ECM coupler with a 
needle pointed tester probe to prevent terminal damage.

 

NOTE

After repairing the trouble, clear the DTC using SDS tool. Refer to “Use of SDS Diagnosis Reset 
Procedures” (Page 1A-14).

 

Detected Condition

Possible Cause

Some failure exists in the fuel injector signal in a high 
load, high revolution condition.

• Injector circuit open or short.

• Injector malfunction.

• ECM malfunction.

ECM

Fuel pump relay

Secondary fuel injector

Y/R

Lg

Lg/W
Lg/B

Lg/Bl

#22
#32
#42

#12

To engine  
stop switch

#2

#3

#4

#1

59
58

56

57

I947H1110125-01

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 27 28 29 30 31 32 33 34 35 36

37 38 39 40 41 42 43 44 45 46 47 48

49 50 51 52 53 54 55 56 57 58 59 60

61 62 63 64 65 66 67 68 69 70 71 72

I837H1110007-02

1A-92 Engine General Information and Diagnosis: 

Step

Action

Yes

No

1

1) Turn the ignition switch OFF.

2) Lift and support the fuel tank. Refer to “Fuel Tank 

Removal and Installation” in Section 1G (Page 1G-9).

3) Check the secondary fuel injector coupler (1) for loose or 

poor contacts.
If OK, then measure the injector resistance.

4) Disconnect the injector coupler and measure the 

resistance between terminals.

Special tool

(A):  09900–25008 (Multi circuit tester set)

Tester knob indication
Resistance (

Ω

)

Injector resistance
11 – 13 

Ω

 at 20 

°

C (68 

°

F)

(Terminal – Terminal)

Go to Step 2.

Replace the injector 
with a new one. Refer to 
“Throttle Body 
Disassembly and 
Assembly” in Section 
1D (Page 1D-11).

1

I947H1110061-01

(A)

I947H1110062-01

Engine General Information and Diagnosis:  1A-93

Step

Action

Yes

No

1

5) If OK, then check the continuity between each terminal 

and ground.

Special tool

(A):  09900–25008 (Multi circuit tester set)

Injector continuity

∞

 

Ω

 (Infinity)

Are the resistance and continuity OK?

Go to Step 2.

Replace the injector 
with a new one. Refer to 
“Throttle Body 
Disassembly and 
Assembly” in Section 
1D (Page 1D-11).

2

1) Turn the ignition switch ON.

2) Measure the injector voltage between the Y/R wire and 

ground.

NOTE

Injector voltage can be detected only for 3 
seconds after ignition switch is turned ON.

 

Special tool

(A):  09900–25008 (Multi circuit tester set)

Tester knob indication
Voltage (

)

Injector voltage
Battery voltage
((+) terminal: Y/R – (–) terminal: Ground)

Is the voltage OK?

• Lg wire open or 

shorted to ground, or 
poor “59” connection 
(#1 cylinder side).

• Lg/W wire open or 

shorted to ground, or 
poor “58” connection 
(#2 cylinder side).

• Lg/B wire open or 

shorted to ground, or 
poor “57” connection 
(#3 cylinder side).

• Lg/Bl wire open or 

shorted to ground, or 
poor “56” connection 
(#4 cylinder side).

• If wire and 

connection are OK, 
intermittent trouble or 
faulty ECM.

• Recheck each 

terminal and wire 
harness for open 
circuit and poor 
connection.

• Replace the ECM 

with a known good 
one, and inspect it 
again. Refer to “ECM 
Removal and 
Installation” in 
Section 1C 
(Page 1C-1).

Open circuit in the Y/R 
wire.

(A)

I947H1110063-01

(A)

I947H1110064-01

1A-94 Engine General Information and Diagnosis: 

DTC “C40” (P0505 / P0506 / P0507): ISC Valve Circuit Malfunction

B947H11104024

Detected Condition and Possible Cause

Wiring Diagram

ECM coupler (Harness side)

Troubleshooting

CAUTION

!

 

• Be careful not to disconnect the ISC valve coupler at least 5 seconds after ignition switch is turned 

to OFF. 
If the ECM coupler is disconnected within 5 seconds after ignition switch is turned to OFF, there is a 
possibility of an unusual value being written in the ECM and causing an error of ISC valve operation.

• When using the multi-circuit tester, do not strongly touch the terminal of the ECM coupler with a 

needle pointed tester probe to prevent terminal damage.

 

NOTE

After repairing the trouble, clear the DTC using SDS tool. Refer to “Use of SDS Diagnosis Reset 
Procedures” (Page 1A-14).

 

Detected Condition

Possible Cause

C40/P0505

The circuit voltage of motor drive is 
unusual.

• ISC valve circuit open or shorted to ground.

C40/P0506

Idle speed is lower than the desired idle 
speed.

• Air passage clogged.

• ISC valve is fixed.

• ISC valve preset position is incorrect.

C40/P0507

Idle speed is higher than the desired idle 
speed.

• Disconnected ISC valve hose.

• ISC valve is fixed.

• ISC valve preset position is incorrect.

ECM

ISC. 1A

ISC. 1B

ISC. 2A

ISC. 2B

ISC valve

Y

Bl

Br

G

Y

Bl

Br

G

39

38

37

49

I947H1110065-01

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 27 28 29 30 31 32 33 34 35 36

37 38 39 40 41 42 43 44 45 46 47 48

49 50 51 52 53 54 55 56 57 58 59 60

61 62 63 64 65 66 67 68 69 70 71 72

I837H1110007-02

Engine General Information and Diagnosis:  1A-95

Step

Action

Yes

No

1

1) Turn the ignition switch OFF.

2) Remove the air cleaner box. Refer to “Air Cleaner Box 

Removal and Installation” in Section 1D (Page 1D-7).

3) Check the ISC valve coupler (1) for loose or poor 

contacts.
If OK, then check the ISC valve lead wire continuity.

4) Disconnect the ISC valve coupler and ECM coupler. 

Refer to “ECM Removal and Installation” in Section 1C 
(Page 1C-1).

5) Check the continuity between terminal “A” and terminal 

“39”, terminal “B” and terminal “38”, terminal “C” and 
terminal “37”, terminal “D” and terminal “49”.

Special tool

(A):  09900–25008 (Multi circuit tester set)
(B):  09900–25009 (Needle-point probe set)

Tester knob indication
Continuity test (

)

ECM couplers (Harness side)

Is the continuity OK?

Go to Step 2.

Bl, Y, G or Br wire open.

1

I947H1110066-01

(A)

(B)

“A”

“C”

“D”

“B”

“37”

“38”

“39”

“49”

I947H1110067-01

1A-96 Engine General Information and Diagnosis: 

2

1) Check the continuity between each ISC valve terminal 

and ground.

Special tool

(A):  09900–25008 (Multi circuit tester set)

Tester knob indication
Resistance (

Ω

)

ISC valve continuity

∞

 

Ω

 (Infinity)

(Terminal – Ground)

2) If OK, then measure the resistance (between the Bl wire 

terminal “A” and Y wire terminal “B”) and (between the G 
wire terminal “C” and Br wire terminal “D”).

ISC valve resistance
Approx. 80 

Ω

 at 20 

°

C (68 

°

F)

(Terminal: “A” – Terminal: “B”, Terminal: “C” – 
Terminal: “D”)

Is the resistance OK?

If wire is OK, 
intermittent trouble or 
faulty ECM.

Replace the ISC valve 
with a new one. Refer to 
“Throttle Body Removal 
and Installation” in 
Section 1D (Page 1D-
10).

Step

Action

Yes

No

(A)

I947H1110068-01

(A)

“A”

“B”

“C”

“D”

I947H1110069-01

Engine General Information and Diagnosis:  1A-97

ACTIVE CONTROL INSPECTION (ISC RPM 
CONTROL)
Check 1

1) Set up the SDS tool. (Refer to the SDS operation 

manual for further details.)

2) Check that the engine is running.

3) Click the “Active control”.

4) Click the “ISC rpm control” (1).

5) Check that the “Spec” (2) is idle speed 1 150 

±

 100 

rpm.

6) Check that the “Desired idle speed” (3) is within the 

specified idle rpm.

Check 2

1) Click the button (4) and decrease the “Spec” (2) to 1 

050 rpm slowly.

2) Check that the “Desired idle speed” (3) is nearly 

equal to the “Spec” (2). At the same time, check that 
the number of steps (5) in the ISC valve position 
decreases.

3) Click the button (6) and increase the “Spec” (2) 

slowly.

4) Check that the “Desired idle speed” (3) is nearly 

equal to the “Spec” (2). Also, check that the number 
of steps (5) in the ISC valve position increases.

Check 3

1) Click the button (6) and increase the “Spec” (2) to 1 

500 rpm slowly.

2) Check that the “Desired idle speed” (3) is nearly 

equal to the “Spec” (2). Also, check that the number 
of steps (5) in the ISC valve position increases.

1

I947H1110130-02

2

I947H1110152-01

3

I947H1110153-01

2

6

4

I947H1110154-01

3

5

I947H1110155-01

2

6

I947H1110156-01

3

5

I947H1110157-01