Iac Valve Troubleshooting - Honda BF135A Manual

• IAC Valve Troubleshooting

DTC 14-1: IAC valve current is abnormal
1. Symptom reproduction test
-1. Connect the HDS pocket tester and clear the DTC
once. If the DTC can not be cleared, go on the trou-
bleshooting.
-2. Start the engine and let it run at idling under no load.
-3. Measure the engine speed using the HDS pocket
tester.
Is the engine speed 650 min
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 No. 1 and No. 2
terminals of the IAC valve.
IAC VALVE SIDE 2P
CONNECTOR
VIEWED FROM THE
TERMINAL SIDE
Is the measured 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.
5-41
-1 (rpm) or above?
-2. Check for the continuity between the IAC valve No. 2
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 – Perform "4. IAC valve line open circuit check".
4. IAC valve line open circuit check
-1. Connect the IAC valve 2P connector.
-2. Disconnect the ECM connector B.
-3. Measure the resistance between the No. 26
(Green/White) and the No. 34 (Black) terminals of the
ECM connector B.
ECM CONNECTOR B
EACVM
(BLACK)
VIEWED FROM THE
TERMINAL SIDE
Is the measured resistance 10 – 13 ?
YES – Perform "5. IAC valve line short circuit check".
NO – Repair open in the wire between the ECM
and the IAC valve.
BF135A•BF150A
EACVP
(GREEN/WHITE)