HONDA marine BF135A, Руководство по ремонту, Страница: 38 / 49

5-35
4. Heater line short circuit check
-1. Turn the ignition switch OFF and disconnect the
ECM connector C.
-2. Check for the continuity between the No. 3
(Black/White) terminal of the ECM connector C and
the engine ground, and between the No. 4 (White)
terminal of the ECM connector C and the engine
ground.
Is there the continuity?
YES – Repair short in the wire between the A/F
sensor and the ECM.
NO – Perform “5. Heater line open circuit check”.
5. Heater line open circuit check
-1. Turn the ignition switch OFF and connect the A/F
sensor 4P connector.
-2. Measure the resistance between the No. 3
(Black/White) and the No. 4 (White) terminals of the
ECM connector C.
Is the resistance 2 – 3 (at room temperature)?
YES – Replace the A/F sensor and recheck. If it is
still abnormal, substitute a known-good
ECM and recheck.
NO – Repair open in the wire between the A/F
sensor and the ECM.
DTC 41-4: A/F sensor heater is abnormal
1. Symptom reproduction test
-1. Connect the Dr. H and clear the DTC once. If the
DTC can not be cleared, go on the troubleshooting.
-2. Start the engine and warm it up for 5 minutes or
more by running the engine at 3,000 min -1 (rpm)
under no load.
-3. Check the DTC again using the Dr. H.
Does the DTC 41-4 appear?
YES – Perform “2. A/F heater relay check”.
NO – Temporary failure (Disappeared)
2. A/F heater relay check
-1. Turn the ignition switch OFF and disconnect the A/F
sensor 4P connector.
-2. Turn the ignition switch ON. Measure the voltage
between the No. 3 (White) terminal of the A/F sensor
harness side 4P connector and the engine ground.
Is there the battery voltage?
YES – Perform “3. A/F heater harness check”.
NO – Go to the step 3.
-3. Turn the ignition switch OFF and disconnect the A/F
heater relay 4P connector.
-4. Measure the voltage between the No. 1 (White/
Green) terminal of the A/F heater relay harness side
4P connector and the engine ground.
• Note that the battery voltage is constantly
applied to the White/Green terminal. Take care
not to short-circuit the terminal.
VIEWED FROM THE
TERMINAL SIDE
A/F SENSOR HARNESS
SIDE 4P CONNECTOR
VIEWED FROM THE
TERMINAL SIDE
AFHT+
(WHITE)
A/F HEATER RELAY HARNESS
SIDE 4P CONNECTOR
VIEWED FROM THE TERMINAL SIDE
+B (WHITE/GREEN)
ECM CONNECTOR C
ECM CONNECTOR C
AFHT
(BLACK/WHITE)
AFHT+ (WHITE)
AFHT
(BLACK/WHITE)
AFHT+ (WHITE)
VIEWED FROM THE
TERMINAL SIDE