Iac Valve Troubleshooting - Honda BF135A Manual

5. BARO sensor ground line open circuit check
-1. Turn the ignition switch ON. Measure the voltage
between the No. 1 (Green/Red) terminal of the BARO
sensor harness side 3P connector and the engine
ground.
BARO SENSOR HARNESS SIDE
3P CONNECTOR
SG2
(GREEN/RED)
VIEWED FROM THE TERMINAL SIDE
Is there the continuity?
YES – Perform "6. BARO sensor check".
NO – Repair open in the wire between the BARO
sensor and the engine ground.
6. BARO sensor check
-1. Turn the ignition switch ON.
-2. Measure the voltage between the A-5 terminal (+) and
the A-2 terminal (–) of the test harness.
A-2
Is the measurement 2.76 – 2.96V?
YES – Substitute a known-good ECM and recheck.
NO – Replace the BARO sensor and recheck.
5-81
A-5

• IAC Valve Troubleshooting

MIL blinks 14 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. Start the engine. Check the engine speed during
idling.
Is the engine speed 650 rpm or above?
YES – Temporary failure (Disappeared)
NO – Perform "2. IAC valve open circuit check".
2. IAC valve open circuit check
-1. Turn the ignition switch OFF and disconnect the IAC
valve 2P connector.
-2. Measure the resistance between the IAC valve No. 1
and the No. 2 terminals.
VIEWED FROM THE TERMINAL SIDE
Is the resistance 8 – 12 ?
YES – Perform "3. IAC valve short circuit check".
NO – Replace the IAC valve.
3. IAC valve short circuit check
-1. Check for the continuity between the IAC valve No. 1
terminal and the body ground.
IAC VALVE SIDE
2P CONNECTOR
VIEWED FROM THE TERMINAL SIDE
Is there the continuity?
YES – Replace the IAC valve.
NO – Go to the step 2.
BF135A•BF150A
IAC VALVE SIDE
2P CONNECTOR