4-70 FI SYSTEM DIAGNOSIS
Step 1
ECM power supply circuit check
1) Turn the ignition switch OFF.
2) Remove the seat. (
8-5)
3) Disconnect the ECM couplers
1
.
4) Check for proper terminal connection to the ECM couplers.
5) If connections are OK, Measure the voltage between R/Y and
ground.
09900-25008: Multi circuit tester set
09900-25009: Needle-point probe set
Tester knob indication: Voltage (
)
ECM input voltage:
Battery voltage
(
+
terminal: R/Y –
-
terminal: Ground)
Is check result OK?
DTC “C42” (P1650): IG SWITCH CIRCUIT MALFUNCTION
DETECTED CONDITION AND POSSIBLE CAUSE
TROUBLESHOOTING
NOTE:
Refer to IGNITION SWITCH INSPECTION for details. (
9-43)
1
YES
Replace the ECM with a known good one, and
inspect it again.
NO
Check Fuel fuse for blowout. If fuse is not blown,
repair or replace the R/Y wire.
DETECTED CONDITION
POSSIBLE CAUSE
Ignition switch signal is not input to the ECM.
• Ignition system circuit open or short.
• ECM malfunction.
1
