C11" Cmp Sensor Circuit Malfunction - Suzuki GSX-R750 Service Manual

4-34 FI SYSTEM AND INTAKE AIR SYSTEM

"C11" CMP SENSOR CIRCUIT MALFUNCTION

DETECTED CONDITION
No CMP sensor signal for 4 seconds at engine
cranking.
INSPECTION
• Lift and support the fuel tank with its prop stay. ( 4-51)
• Remove the air cleaner box. ( 4-61 and -62)
Turn the ignition switch OFF.
1
Check the CMP sensor coupler for loose or poor contacts.
If OK, then measure the CMP sensor resistance.
Disconnect the CMP sensor coupler and measure the re-
sistance.
CMP sensor resistance: 0.9 – 1.7 kΩ Ω Ω Ω Ω
If OK, then check the continuity between each terminal
and ground.
CMP sensor continuity: ∞Ω
[ 09900-25008: Multi circuit tester
U Tester knob indication: Resistance (Ω Ω Ω Ω Ω )
Yes
2 Disconnect the CMP sensor coupler.
Crank the engine a few seconds with the starter motor, and
measure the CMP sensor peak voltage at the sensor.
CMP sensor peak voltage: More than 0.7 V
Repeat the above test procedure a few times and mea-
sure the highest peak voltage.
If OK, then measure the CMP sensor peak voltage at the
ECM terminals. (G+/G– or [/d)
[ 09900-25008: Multi circuit tester
V Tester knob indication: Voltage (
No
Yes
B/Y or Br wire open or shorted to ground, or poor [ or d
connection. ( 4-25)
If wire and connection are OK, intermittent trouble or faulty ECM.
Recheck each terminal and wire harness for open circuit and
poor connection. ( 4-4)
(Terminal – Terminal)
∞Ω ∞Ω (Infinity) ∞Ω
∞Ω
(Terminal – Ground)
No Replace the CMP sensor
with a new one.
(B/Y – Br)
)
Loose or poor contacts on the CMP
sensor coupler or ECM coupler.
Replace the CMP sensor with a
new one.
Replace the ECM with a new one,
and inspect it again.
POSSIBLE CAUSE
• Metal particles or foreign material being
attached on the CMP sensor and rotor tip.
• CMP sensor circuit open or short.
• CMP sensor malfunction.
• ECM malfunction.
1
2
V
Peak volt
adaptor
ECM couplers