Shooting - Honda BF135A Manual

BF135A•BF150A
3. Knock sensor signal line short circuit test
-1. Check for the continuity between the No. 15 (Red/Blue)
terminal of the ECM connector A and the body ground.
ECM CONNECTOR A
VIEWED FROM THE
TERMINAL SIDE
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.
• A/F Heater Troubleshooting
DTC 41-3: A/F heater is abnormal
1. Symptom reproduction test
-1. Connect the HDS pocket tester and clear the DTC
-2. Start the engine and warm it up 5 minutes or more by
KS (RED/BLUE)
-3. Check the DTC again using the HDS pocket tester.
2. A/F heater relay check
-1. Turn the ignition switch OFF and disconnect the A/F
-2. Turn the ignition switch ON. Measure the voltage
-3. Turn the ignition switch OFF and disconnect the A/F
-4. Measure the voltage between the No. 1 (White/ Green)
once. If the DTC can not be cleared, go on the trou-
bleshooting.
running the engine at 3,000 min
Does the DTC 41-3 appear?
YES – Perform "2. A/F heater relay check".
NO – Temporary failure (Disappeared)
sensor 4P connector.
between the No. 3 (White) terminal of the A/F sensor
harness side 4P connector and the engine ground.
A/F SENSOR HARNESS
SIDE 4P CONNECTOR
AFHT+ (WHITE)
VIEWED FROM THE TERMINAL SIDE
Is there the battery voltage?
YES – Perform "3. A/F sensor heater check".
NO – Go to the step 3.
heater relay 4P connector.
terminal of the A/F heater relay harness side 4P con-
nector and the engine ground.
• Note that the battery voltage is constantly applied to
the White/Green terminal. Take care not to short-cir-
cuit the terminal.
A/F HEATER RELAY HARNESS
SIDE 4P CONNECTOR
+B (WHITE/GREEN)
VIEWED FROM THE
TERMINAL SIDE
-1 (rpm) under no load.
5-44