BF135A•BF150A
5-42
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.
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
once. If the DTC can not be cleared, go on the trou-
bleshooting.
-2. Start the engine and warm it up for 5 minutes by run-
ning the engine at 3,000 min
-1
(rpm) under no load.
-3. Disconnect the neutral switch 2P connector.
-4. Increase the engine speed gradually and run the
engine at 4,500 min
-1
(rpm) for a few seconds.
-5. Check the DTC again using the HDS pocket tester.
Does the DTC 21-1 appear?
YES –
Perform “2. Spool solenoid valve check”.
NO –
Temporary failure (Disappeared)
2. Spool solenoid valve check
-1. Turn the ignition switch OFF and disconnect the spool
solenoid valve connector.
-2. Measure the resistance between the spool solenoid
valve side 1P connector (Green/White) terminal and
the body ground.
Is the measured resistance 12 – 18
?
YES –
Perform “3. VTEC signal line short circuit
check”.
NO –
Replace the spool solenoid valve.
ECM CONNECTOR B
VIEWED FROM THE
TERMINAL SIDE
SOLENOID VALVE SIDE
1P CONNECTOR
VIEWED FROM THE
TERMINAL SIDE
EACVM
(BLACK)
EACVP
(GREEN/WHITE)