C29" Stp Sensor Circuit Malfunction - Suzuki GSX-R750 Service Manual

11-8 GSX-R750K2 ('02-MODEL)

"C29" STP SENSOR CIRCUIT MALFUNCTION

DETECTED CONDITION
Signal voltage low or high.
Difference between actual throttle opening and
opening calculated by ECM in larger than specified
value.
0.2 V Sensor Voltage < 4.8 V
(
without the above range.
INSPECTION
• Lift and support the fuel tank with its prop stay.
1
Turn the ignition switch OFF.
Check the STP sensor coupler for loose or poor contacts.
If OK, then measure the STP sensor input voltage.
Disconnect the STP sensor coupler (White color).
Turn the ignition switch ON.
Measure the voltage at the Red wire and ground.
If OK, then measure the voltage at the Red wire and B/Br wire.
STP sensor input voltage: 4.5 – 5.5 V
[ 09900-25008: Multi circuit tester
V Tester knob indication: Voltage (
Yes
2 Turn the ignition switch OFF.
Remove the air cleaner element.
Disconnect the STP sensor coupler (White color).
Check the continuity between Yellow wire and ground.
STP sensor continuity: ∞Ω
If OK, then measure the STP sensor resistance at the cou-
pler (between Yellow and Black wires).
Close and open the secondary throttle valve by finger, and
measure the valve closing and opening resistance.
STP sensor resistance
Secondary throttle valve is closed:
Secondary throttle valve is opened: Approx. 3.9 kΩ Ω Ω Ω Ω
[ 09900-25008: Multi circuit tester
U Tester knob indication: Resistance (Ω Ω Ω Ω Ω )
)
+Red – -Ground
(
+Red – -B/Br
)
No
Loose or poor contacts on
the ECM coupler.
Open or short circuit in the
Red wire or B/Br wire.
∞Ω ∞Ω (Infinity) ∞Ω
∞Ω
(Yellow wire – Ground)
Approx. 0.5 kΩ Ω Ω Ω Ω
No
Reset the STP sensor
position correctly.
(22)
Replace the STP sensor
with a new one.
POSSIBLE CAUSE
• STP sensor maladjusted.
• STP sensor circuit open or short.
• STP sensor malfunction.
• ECM malfunction.
)
1
1
V
Ground Ground
V
Red
Ground
B/Br
Red