Suzuki GSX-R 1000 Service Manual: DTC “c15” (p0115-h/l): ect sensor circuit
malfunction
Detected condition and possible cause
Detected condition |
Possible cause |
C15 |
Output voltage is not with in the following
range.
0.15 V ≤ Sensor voltage < 4.85 V |
- Ect sensor circuit open or short.
- Ect sensor malfunction.
- Ecm malfunction.
- Ect sensor circuit is open or ground circuit open.
- Ect sensor circuit shorted to ground.
|
P0115 |
H |
Sensor voltage is higher than specified
value. |
L |
Sensor voltage is lower than specified
value. |
Wiring diagram

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” . |
C15 (use of mode select switch)
Step |
Action |
Yes |
No |
1 |
- Turn the ignition switch off.
- Remove the left side cowling. Refer to “exterior parts removal
and installation” in section 9d .
- Check the ect sensor coupler (1) for loose or poor
contacts.
If ok, then measure the ect sensor input voltage.

- Disconnect the ect coupler and turn the ignition switch
on.
- Measure the input voltage between the b/bl wire and
ground.
If ok, then measure the input voltage between the b/bl
wire and b/br wire.
Special tool
(a): 09900–25008 (multi
circuit tester set)
Tester knob indication
voltage ( )
Ect sensor input voltage
4.5 – 5.5 V
((+) terminal: b/bl – (–) terminal: ground, (+)
terminal: b/bl – (–) terminal: b/br)

Is the voltage ok? |
Go to step 2. |
- Loose or poor
contacts on the ecm
coupler.
- Open or short circuit
in the b/bl or b/br
wire.
|
P0115-h (use of sds)
Step |
Action |
Yes |
No |
1 |
- Turn the ignition switch off.
- Remove the left side cowling. Refer to “exterior parts removal
and installation” in section 9d .
- Check the ect sensor coupler (1) for loose or poor
contacts.
If ok, then check the ect sensor lead wire continuity.

- Disconnect the ect sensor coupler.
- Disconnect the ecm coupler. Refer to “ecm removal and
installation” in section 1c .
- Insert the needle pointed probes to the lead wire coupler.
- Check the continuity between the b/bl wire and terminal
“32”. 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 2. |
B/bl or b/br wire open. |
P0115-l (use of sds)
Step |
Action |
Yes |
No |
1 |
- Turn the ignition switch off.
- Remove the left side cowling. Refer to “exterior parts removal
and installation” in section 9d .
- Check the ect sensor coupler (1) for loose or poor
contacts.
If ok, then check the ect sensor lead wire continuity

- Disconnect the ect sensor coupler.
- Check the continuity between the b/bl wire and ground.
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 ( )

- Connect the ect sensor coupler.
- Insert the needle pointed probes to the lead wire coupler.
- Turn the ignition switch on.
- Measure the output voltage between the b/bl wire and
ground.
Special tool
(a): 09900–25008 (multi
circuit tester set)
(b): 09900–25009
(needle-point probe set)
Tester knob indication
voltage ( )
Ect sensor output voltage
0.15 – 4.85 V
((+) terminal: b/bl – (–) terminal: ground)

Are the continuity and voltage ok? |
Go to step 2. |
- B/bl wire shorted to
ground.
- If wire is ok, go to
step 2.
|
2 |
- Turn the ignition switch off.
- Disconnect the ect sensor coupler.
- Measure the ect sensor resistance.
Special tool
(a): 09900–25008 (multi
circuit tester set)
Tester knob indication
resistance (Ω)
Ect sensor resistance
approx. 2.45 KΩ at 20 °c (68 °f)
(terminal – terminal)

Note
refer to “ect sensor inspection” in section 1c for details. |
Is the resistance ok? |
- B/bl or b/br wire
open or shorted to
ground, or poor “32”
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 .
|
Replace the ect
sensor with a new one.
Refer to “ect sensor removal and installation” in section 1c . |
Detected condition and possible cause
Detected condition
Possible cause
C14
Output voltage is not within the following
range.
Difference between actual throttle op ...
Detected condition and possible cause
Detected condition
Possible cause
C21
Output voltage is not with in the following
range.
0.15 V ≤ Sensor voltage < ...
Other materials:
Service data
Valve + guide
unit: mm (in
Camshaft + cylinder head
unit: mm (in
Cylinder + piston + piston ring
unit: mm (in)
Conrod + crankshaft
unit: mm (in)
Balancer
unit: mm (in)
Throttle body
...
Voltage check
If voltage is supplied to the circuit being checked, voltage
check can be used as circuit check.
With all connectors/couplers connected and voltage
applied to the circuit being checked, measure
voltage between each terminal and body ground.
If measurements were taken as shown ...
Specifications
Service data
Fi sensors
Tightening torque specifications
Reference: for the tightening torque of fastener not specified in this
section, refer to “tightening torque list” in section 0c . ...