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5-27
BF135A•BF150A
• Tachometer Malfunction
1. Engine speed check using the HDS pocket tester.
-1. Turn the ignition switch OFF and connect the HDS
pocket tester.
-2. Start the engine and check the engine speed with the
HDS pocket tester.
Do the tachometer and tester readings agree?
YES –
Normal (Temporary problem has been
removed.)
NO –
Perform “2. Tachometer power line check”.
*Tolerance of genuine Honda tachometer:
At 2,000 rpm:±160 rpm
At 4,000 rpm:+200 rpm
–150 rpm
At 6,000 rpm:+200 rpm
–150 rpm
2. Tachometer power line check
-1. Turn the ignition switch OFF and disconnect the
Yellow/Black and the Black terminals of the tachome-
ter.
-2. Turn the ignition switch ON and measure the voltage
between the meter harness side Yellow/Black and the
Black terminals.
Is there the battery voltage?
YES –
Perform “3. Tachometer pulse line check”.
NO –
Repair open in the wire of the meter harness.
3. Tachometer pulse line check
-1. Turn the ignition switch OFF and disconnect the ECM
connector B.
-2. Disconnect the remote control harness 14P connector.
-3. Check for the continuity between the No. 12 (Gray) ter-
minal of the main harness side 14P connector and the
engine ground.
Is there the continuity?
YES –
Repair short in the main harness.
NO –
-4. Check for the continuity between the No. 12 (Gray) ter-
minal of the main harness side 14P connector and the
No. 33 (Gray) terminal of the ECM harness side con-
nector B.
Is there the continuity?
YES –
Check for open in the remote control harness
and meter harness wires. If the harnesses are
normal, substitute a known-good ECM and
recheck.
NO –
Repair open in the wire of the main harness.
MAIN HARNESS SIDE
14P CONNECTOR
VIEWED FROM THE
TERMINAL SIDE
MAIN HARNESS SIDE
14P CONNECTOR
ECM CONNECTOR B
VIEWED FROM THE
TERMINAL SIDE
TACHO
(GRAY)
GRAY