Suzuki GSX-R750 Service Manual page 246

4-90 FI SYSTEM DIAGNOSIS
Step 2 (When indicating C44/P0135:)
1) Connect the HO2 sensor coupler.
2) Insert the needle pointed probe to the HO2 sensor coupler.
3) Turn the ignition switch ON and measure the heater voltage
between W (O/W) wire and ground.
4) If the tester voltage indicates the battery voltage, it is good
condition.
 Heater voltage: Battery voltage
NOTE:
Battery voltage can be detected only before starting the engine.
 09900-25008: Multi-circuit tester set
09900-25009: Needle pointed probe set
 Tester knob indication: Voltage ()
Is the voltage OK?
• O/W or W wire open or shorted to ground, or
poor 'a connection.
• Recheck each terminal and wire harness for
open circuit and poor connection.
YES
• If wire and connection are OK, intermittent trou-
ble or faulty ECM.
• Replace the ECM with a known good one, and
inspect it again.
• Open or short circuit in the W/B wire or O/W
wire.
NO
• Loose or poor contacts on the ECM coupler
(Terminal a) or HO2 sensor coupler.

When using the multi-circuit tester, do not storongly
touch the terminal of the ECM coupler with a needle
pointed tester probe to prevent the terminal damage
or terminal bend.
5) After repairing the trouble, clear the DTC using SDS tool.
(4-27)
(+ W – - Ground)
2
2
ECM couplers (Harness side)
V