Honda BF135A Manual page 185

BF135A•BF150A
7. CKP sensor check
-1. Connect the HDS pocket tester and clear the DTC
once.
-2. Start the engine and let it run at idling under no load.
Check the DTC with the HDS pocket tester.
Does the DTC 4-1 appear?
YES – Replace the CKP sensor and recheck. If the
DTC 4-1 appears again, substitute a known-
good ECM and recheck.
NO – End of the check
DTC 4-2: CKP pulse 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 let it run at idling under no load.
-3. Check the DTC with the HDS pocket tester.
Does the DTC 4-2 appear?
YES – Check the crank pulse plate for deformation
and damage. Replace the crank pulse plate
with a new one if it is deformed or damaged,
and check again. If abnormal, replace the
CKP sensor and check. If the DTC 4-2 still
appears, replace the ECM.
NO – Temporary failure (Disappeared)
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