Honda BF135A Manual page 232

3. IAT sensor signal line short circuit check
-1. Turn the ignition switch OFF and disconnect the ECM
connector B.
-2. Check for the continuity between the No. 2 (Red/
Yellow) terminal of the IAT sensor harness side 2P
connector and the body ground.
IAT SENSOR HARNESS SIDE
2P CONNECTOR
VIEWED FROM THE TERMINAL SIDE
Is there the continuity?
YES – Repair short in the wire between the IAT sen-
sor and the ECM.
NO – Perform "4. IAT sensor ground line short cir-
cuit check".
4. IAT sensor ground line short circuit check
-1. Turn the ignition switch OFF.
-2. Check for the continuity between the No. 1 (Green/
Red) terminal of the IAT sensor harness side 2P con-
nector and the body ground.
IAT SENSOR HARNESS SIDE
2P CONNECTOR
SG2 (GREEN/RED)
VIEWED FROM THE TERMINAL SIDE
Is there the continuity?
YES – Perform "5. IAT sensor check".
NO – Repair open in the wire between the IAT sen-
sor and the engine ground.
5-79
TA (RED/YELLOW)
5. IAT sensor check
-1. Turn the ignition switch OFF and disconnect the IAT
sensor 2P connector.
-2. Measure the resistance between the No. 1 and the No.
2 terminals of the IAT sensor side 2P connector.
IAT SENSOR SIDE
2P CONNECTOR
VIEWED FROM THE TERMINAL SIDE
INTAKE AIR TEMPERATURE
Is there the resistance corresponding to the ambient
temperature?
YES – Substitute a known-good ECM and recheck.
NO – Replace the IAT sensor and recheck.
BF135A•BF150A