Cmp Sensor Troubleshooting - Honda BF135A Manual

• CMP Sensor Troubleshooting

MIL blinks 8 times.
1. Symptom reproduction test
-1. Reset the ECM.
-2. Start the engine and let it run at idling under no load.
-3. Check the MIL.
Does the MIL come ON?
YES – Check the pulse plate. If it is normal, perform
"2. CMP sensor power supply line open circuit
check". If it is abnormal, replace the pulse
plate and recheck.
NO – Temporary failure (Disappeared)
2. CMP sensor power supply line open circuit check
-1. Turn the ignition switch ON. Measure the voltage
between the No. 1 (Yellow/Black) terminal of the CMP
sensor harness side 3P connector and the engine
ground.
CMP SENSOR HARNESS SIDE
3P CONNECTOR
IGP
(YELLOW/BLACK)
VIEWED FROM THE TERMINAL SIDE
Is there the battery voltage?
YES – Perform "3. CMP sensor signal line open cir-
cuit check".
NO – Repair open in the wire between the No. 4
fuse and the CMP sensor.
3. CMP sensor signal line open circuit check
-1. Turn the ignition switch ON. Measure the voltage
between the No. 3 (Green) terminal of the CMP sensor
harness side 3P connector and the engine ground.
CMP SENSOR HARNESS SIDE
3P CONNECTOR
VIEWED FROM THE TERMINAL SIDE
5-77
TDC (GREEN)
Is the voltage 4.75 – 5.25V?
YES – Perform "4. CMP sensor signal line short cir-
cuit check".
NO – Repair open in the wire between the CMP
sensor and the ECM.
4. CMP sensor signal line short circuit check
-1. Turn the ignition switch OFF and disconnect the CMP
sensor 3P connector.
-2. Check for the continuity between the No. 3 (Green) ter-
minal of the CMP sensor harness side 3P connector
and the engine ground.
CMP SENSOR HARNESS SIDE
3P CONNECTOR
VIEWED FROM THE TERMINAL SIDE
Is there the continuity?
YES – Repair short in the wire between the CMP
sensor and the ECM.
NO – Perform "5. CMP sensor ground line open cir-
cuit check".
5. CMP sensor ground line open circuit check
-1. Turn the ignition switch OFF and disconnect the CMP
sensor 3P connector.
-2. Check for the continuity between the No. 2 (Green/
Black) terminal of the CMP sensor harness side 3P
connector and the engine ground.
CMP SENSOR HARNESS SIDE
3P CONNECTOR
VIEWED FROM THE TERMINAL SIDE
Is there the continuity?
YES – Perform "6. CMP sensor check".
NO – Repair open in the wire between the CMP
sensor and the engine ground.
BF135A•BF150A
TDC (GREEN)
LG1
(GREEN/BLACK)