CRANKSHAFT POSITION (CKP) SENSOR INSPECTION [LF, L3]

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Note
•  Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart.

Air Gap Inspection

1.  Verify that the CKP sensor is securely installed.

2.  Using a thickness gauge, measure the air gap between the plate projections at the back of crankshaft pulley and the CKP sensor.

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•  If not within the specification, inspect the plate projections for cracks or bending.
―  If there is any malfunction, replace the Crankshaft pulley.
CKP sensor air gap
0.5—1.5 mm {0.02—0.05 in}


Visual inspection

1.  Remove the battery cover.

2.  Disconnect the negative battery cable.

3.  Remove the plug hole plate. (See PLUG HOLE PLATE REMOVAL/INSTALLATION [LF, L3].)

4.  Perform the following procedure for easier access.

(1)  Remove the front tire (RH).
(2)  Remove the splash shield.

5.  Disconnect the CKP sensor connector.

6.  Remove the CKP sensor. (See CRANKSHAFT POSITION (CKP) SENSOR REMOVAL/INSTALLATION [LF, L3].)

7.  Verify that there are no metal shavings on the CKP sensor.

•  If there is a malfunction, replace the CKP sensor.
(See CRANKSHAFT POSITION (CKP) SENSOR REMOVAL/INSTALLATION [LF, L3].)


Voltage Inspection

1.  Idle the engine.

Caution
•  Water penetrating the connector will cause sensor malfunction. To prevent this, be careful not to damage the wiring harnesses or the waterproof connector so as to cause water penetration.

2.  Measure the output voltage using a oscilloscope.

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•  If not within the specification, replace the CKP sensor.
(See CRANKSHAFT POSITION (CKP) SENSOR REMOVAL/INSTALLATION [LF, L3].)

CKP sensor voltage

Terminal

Voltage (V)

Condition
A
1.0 or less
Under any condition
B
4.8 or more
High output*
0.8 or less
Low output*
C
B+
Under any condition

*  :Output voltage varies with crankshaft rotation.


Circuit Open/Short Inspection

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1.  Disconnect the PCM connector. (See PCM REMOVAL/INSTALLATION [LF, L3].)

2.  Inspect the following wiring harnesses for open or short. (Continuity check)


Open circuit

•  If there is no continuity, the circuit is open. Repair or replace the harness.
―  CKP sensor terminal A and body ground
―  CKP sensor terminal B and PCM terminal 2W*1, 2U*2
―  CKP sensor terminal C and PCM terminal 2AQ*1, 2T*2


Short circuit

•  If there is continuity, the circuit is shorted. Repair or replace the harness.
―  CKP sensor terminal A and power supply
―  CKP sensor terminal B and power supply
―  CKP sensor terminal B and body ground
―  CKP sensor terminal C and body ground

*1  :MTX, LF ATX (FS5A-EL)
*2  :LF ATX(FN4A-EL), L3 ATX