C28" Stv Actuator Circuit Malfunction - Suzuki GSX-R750 Service Manual

"C28" STV ACTUATOR CIRCUIT MALFUNCTION

DETECTED CONDITION
The operation voltage does not reach the STVA.
ECM does not receive communication signal from
the STVA.
INSPECTION
• Lift and support the fuel tank with its prop stay.
• Remove the air cleaner element.
1
Turn the ignition switch ON and OFF.
Check the STVA lead wire coupler for loose or poor con-
tacts.
Turn the ignition switch ON to check the STVA operation.
(STV operating order: Full close → Full open → 20% open)
Yes
2
Turn the ignition switch OFF.
Disconnect the STVA lead wire coupler.
Check the continuity between each wire and ground.
STVA continuity: ∞Ω
If OK, then measure the STVA resistance. (between Pink
and Black wires) and (between W/B and Green wires)
STVA resistance: Approx. 6.5 Ω Ω Ω Ω Ω
[ 09900-25008: Multi circuit tester
U Tester knob indication: Resistance (Ω Ω Ω Ω Ω )
Yes
Loose or poor contacts on the STVA coupler.
If wire and connection are OK, intermittent trouble or faulty
ECM. Recheck each terminal and wire harness for open cir-
cuit and poor connection.
No
Loose or poor contacts on
the STVA coupler.
Open or short circuit in the
(Pink or Black) and (W/Bl
or Green) wires.
∞Ω ∞Ω
∞Ω ∞Ω (Infinity)
(+ Pink – - Black)
(+ + + + + W/B – - - - - - Green)
No
Replace the STVA
with a new one.
Replace the ECM with
new one, and inspect it
again.
POSSIBLE CAUSE
• STVA malfunction.
• STVA circuit open or short.
• STVA motor malfunction.
1
1
2
2
GSX-R750K2 ('02-MODEL) 11-7
Ground Ground
9