MPI <4G63>
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Troubleshooting
13D-81
Examples of Abnormal Wave Patterns
D
Example 1
Cause of problem
Sensor interface malfunction
Wave pattern characteristics
Rectangular wave pattern is output even when the engine
is not started.
D
Example 2
Cause of problem
Damaged rectifier or vortex generation column
Wave pattern characteristics
Unstable wave pattern with non
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uniform frequency.
However, when an ignition leak occurs during acceleration,
the wave pattern will be distorted temporarily, even if
the air flow sensor is normal.
CAMSHAFT POSITION SENSOR AND CRANK ANGLE
SENSOR
Measurement Method
1.
Disconnect the camshaft position sensor connector and
connect the special tool test harness (MB991709) in
between (All terminals should be connected).
2.
Connect the oscilloscope special pattern pickup to
camshaft position sensor terminal No. 2.
3.
Disconnect the crank angle sensor connector and connect
the special tool test harness (MD998478) in between.
4.
Connect the oscilloscope special patterns pickup to crank
angle sensor terminal No. 2.
Alternate Method (Test harness not available)
1.
Connect the oscilloscope special patterns pickup to
engine-A/T-ECU terminal No. 56 (When checking the
camshaft position sensor signal wave pattern).
2.
Connect the oscilloscope special patterns pickup to
engine-A/T-ECU terminal No. 45 (When checking the
crank angle sensor signal wave pattern).
Crank angle
sensor connector
Camshaftposition
sensor connector
Oscilloscope
Special patterns
pick-up