Inspect the camshaft sprocket in the following procedures:
If they are worn or damaged, replace the sprocket/ camshaft assembly and cam chain as a set.

Camshaft inspection
Cam chain tension adjuster inspectionDTC “c23” (p1651-h/l): to sensor circuit
malfunction
Detected condition and possible cause
Detected condition
Possible cause
C23
The sensor voltage should be the
following for 2 sec. And more, after ignition
switch is turned on.
0.2 V ≤ Sensor voltage < 4.8 V
To sensor circuit open or shor ...
Starter clutch inspection
Refer to “starter clutch removal and installation” .
Starter clutch
Install the starter driven gear onto the starter clutch.
Turn the starter driven gear by hand to inspect the
starter clutch for a smooth movement. The gear
turns in one direction only. If a large resistance is felt
...
Oil pump inspection
Inspect the oil pump in the following procedures:
remove the oil pump. Refer to “oil pump removal and installation” .
Rotate the oil pump by hand and check that it moves
smoothly. If it does not move smoothly, replace the
oil pump assembly.
Caution
do not attempt t ...