Suzuki kq750 2008, Service Manual

Page: 133 / 576

Engine General Information and Diagnosis: 1A-62
DTC “C40” (P05057): ISC Valve Circuit Malfunction
B831G21104019
Detected Condition and Possible Cause
Wiring Diagram
ECM coupler (Harness side)
Troubleshooting
CAUTION
!
• Be careful not to disconnect at lease 3 seconds after ignition switch is turned to OFF.
If the ECM coupler is disconnected within 3 seconds after ignition switch is turned to OFF, there is a
possibility of an usual valve being written in 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 the terminal damage or terminal bend.
NOTE
After repairing the trouble, clear the DTC using SDS tool. Refer to “Use of SDS Diagnosis Reset
Procedures (Page 1A-13)”.
Detected Condition Possible Cause
No voltage is applied to ISC valve motor, although ignition
switch is turned ON, or voltage is applied to ISC valve
motor, although ignition switch is turned OFF. • ISC valve circuit open or shorted to the ground.
• ISC valve malfunction.
• ECM malfunction.
ISC valve
ECM
IS1A
M
BATT
IS1B
B/Lg
R/B
P/W
IS2A G
IS2B
W/Bl
17
4
34
16
33
I831G1110062-01
I831G1110019-01