Suzuki GA413 Service Manual page 942

6F-10 IGNITION SYSTEM
8) If ignition timing is out of specification, check the followings:
D CKP sensor
D Crankshaft timing belt pulley (signal rotor)
D TP sensor
D Test switch signal circuit (if equipped)
D VSS
9) After checking Initial Ignition Timing, release ignition timing
fixation by using SUZUKI scan tool or disconnect service wire
from monitor connector.
10) With engine idling (initial ignition timing not fixed, throttle open-
ing at closed position and car stopped), check that ignition tim-
ing fluctuates between 65 – 165 BTDC. (Constant variation
within a few degrees from 65 – 165 indicates no abnormality but
proves operation of electronic timing control system.) Also,
check that increasing engine speed advances ignition timing.
If above check results are not satisfactory, check CKP sensor,
test switch terminal circuit and ECM.
11) Install the inspection hole cap and engine service hole cover.