Honda BF135A - Ect Sensor 2 Troubleshooting

BF135A•BF150A
5-84
3. Knock sensor signal line short circuit check
-1. Check for the continuity between the test harness A-15
terminal and the engine ground.
Is there the continuity?
YES – Repair short in the wire between the ECM
and the spool solenoid valve.
NO – Substitute a known-good ECM and recheck.
• ECT Sensor 2 Troubleshooting
MIL blinks 24 times
1. Symptom reproduction test
-1. Reset the ECM.
-2. Turn the ignition switch OFF and connect the test har-
ness.
• Hold the sensor connector connected.
-3. Turn the ignition switch ON.
-4. Measure the voltage between the test harness B-12
terminal (+) and the A-2 terminal (–).
Is the voltage 0.08 – 4.99V?
YES – Temporary failure (Disappeared)
NO – Perform "2. ECT sensor 2 signal line open cir-
cuit check".
2. ECT sensor 2 signal line open circuit check
-1. Turn the ignition switch OFF. Disconnect the 2P con-
nector from the ECT sensor 2.
-2. Turn the ignition switch ON.
-3. Measure the voltage between the No. 2 (Red/Black)
terminal of the ECT sensor 2 harness side 2P con-
nector and the engine ground.
Is the voltage 4.75 – 5.25V?
YES – Perform "3. ECT sensor 2 ground line short
circuit check".
NO – Repair open in the wire between the ECT
sensor 2 and the ECM.
A-15
A-2
B-12
ECT SENSOR 2 HARNESS SIDE
2P CONNECTOR
VIEWED FROM THE TERMINAL SIDE
TOH1 (RED/BLACK)