Vtec Solenoid Valve; Troubleshooting - Honda BF135A Manual

BF135A•BF150A
5. IAC valve line short circuit check
-1. Check for the continuity between the No. 26
(Green/White) terminal of the ECM connector B and
the engine ground, and between the No. 34 (Black) ter-
minal of the ECM connector B and the engine ground.
ECM CONNECTOR B
EACVM
(BLACK)
VIEWED FROM THE
TERMINAL SIDE
Is there the continuity?
YES – Repair short in the wire between the ECM
and the IAC valve.
NO – Substitute a known-good ECM and recheck.
• VTEC Solenoid Valve Troubleshooting
DTC 21-1: VTEC solenoid valve output is abnormal
1. Symptom reproduction test
-1. Connect the HDS pocket tester and clear the DTC
-2. Start the engine and warm it up for 5 minutes by run-
EACVP
(GREEN/WHITE)
-3. Disconnect the neutral switch 2P connector.
-4. Increase the engine speed gradually and run the
-5. Check the DTC again using the HDS pocket tester.
2. Spool solenoid valve check
-1. Turn the ignition switch OFF and disconnect the spool
-2. Measure the resistance between the spool solenoid
once. If the DTC can not be cleared, go on the trou-
bleshooting.
ning the engine at 3,000 min
engine at 4,500 min -1 (rpm) for a few seconds.
Does the DTC 21-1 appear?
YES – Perform "2. Spool solenoid valve check".
NO – Temporary failure (Disappeared)
solenoid valve connector.
valve side 1P connector (Green/White) terminal and
the body ground.
SOLENOID VALVE SIDE
1P CONNECTOR
VIEWED FROM THE
TERMINAL SIDE
Is the measured resistance 12 – 18 ?
YES – Perform "3. VTEC signal line short circuit
check".
NO – Replace the spool solenoid valve.
-1 (rpm) under no load.
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