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George H.
George H., Hyundai Technician
Category: Hyundai
Satisfied Customers: 18666
Experience:  Hyundai Gold certified, ASE Master tech 15+ years
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Hyundai Sonata 2002 Hyundai Sonata 4 cyl will not start-had

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2002 Hyundai Sonata 4 cyl will not start-had a cps code-sensor broke-replaced sensor-still not firing injector

Hello I will help you with your question,


This is the sensor at the snout of the crankshaft that you replaced?


Was the timing belt replaced as well?


Were all the stripped teeth removed from the crank area?


Was the wire for the sensor routed behind the power steering pump? Was the pump loosened to replace the sensor?


Was the shutter wheel replaced in the correct directionn of travel?


Usually it is one of these things that was done/not done that either breaks the new sensor, sends the wrong signal to the computer or cuts the sensor wire.


If you have a voltmeter make sure you have power and ground to the harness side of the connector with the key on and measure the other wire with a straight pin slid along the wire side of the connector so you can have it connected while you turn the crankshaft by hand, the voltage should toggle high to low as you turn the crank. If the voltage does not toggle then the problem is in the sensor or the wiring to the sensor from the connector.


Let me know what I can do to help you with this


Thank you



Customer: replied 6 years ago.
yes to above-the shutter wheel was not replace-scanner shows code gone but have no ground signal to injectors-have power but pulsating ground not ther-have noid switch in injector connection-am mechanic for 40 yyears-using alldata books on-line-no color codes on wires coming out of pcm

Good now I know what you are working with. Do you see cranking RPMs?



Customer: replied 6 years ago.
no cranking signal?-no rpm movement on my scanner-also no codes
Ok if there is no RPM then you will have to check at the crank sensor connector for power ground and signal as the crank is turned, disconnect the coil connectors in case the engine decides to start while you are turning the crank. See if the voltage toggles on the signal line. I often see the wiring cut by the timing belt if it is not installed in excatly the right place so if you have power and ground to the sensor but no toggle then the wire would have to be inspected.
Customer: replied 6 years ago.
the cps po335 code is not present-i went and bought a used ecm-still same problem-no ground to injector
Customer: replied 6 years ago.

at the 3 connectors-i have a 12 volt signal,i have a 5 volt at the second-the other s/b interupt signal-still no pulse at injector or the pulsating ground-have a noid in harness connector to 1 injector-have power to 2 prong connector


Customer: replied 6 years ago.
what color is this signal wire out of the 3

The 5 volt signal should be the signal and it should toggle from 5 volts to ground when you turn the crank. If it does not was the shutter wheel reinstalled to the crank snout?


You should not be able to replace the sensor without removing the shutter wheel as it slides in the sensor gap a little and prevents you from removing/installing the sensor.


The signal wire color on the harness side is not given so the pair of connectors that are side by side are the ground connection and the signal connection (look for the 5 volts when you rotate the crank


Let me know if you see the toggle, all the rest is secondary until you get the crank signal to the computer.



Customer: replied 6 years ago.


believe i found problem-looks like i installed sensor backwards

Thats pretty tough to do but as long as you found the problem.


Is the sensor broken?



Customer: replied 6 years ago.

no its very easy if u not a hy mechanic-the orignal was broken-it was flat-i had the slot magnet facing outwards-totally missed shutter plate-no break or anything-reassemble now-will let u know


Ok let me know if there is anything I can do to help



Customer: replied 6 years ago.
well its running but has a idlying problem and cutouts on steady speed-acceleration gets cutout and miss but will cruise at a steady speed-any advise will help me-specially u being a hyundai mechanic-i was a indepenant shop mechanic all my life-made a good living-retired working a little to stay busy-i am 68-always luv mechanics-dad was a mechanic at buick dealership-always made better money at independant shops-i will pay the 18 at least-council was worth it-will inform tomorrow

One of the things I see with this engine is leaking valve covers so check the two plug wires and the two plug boots for oil contamination along with the spark plugs. This engine only likes NGK or Denso plugs.


The PCV hose that runs from the intake plenum to the valve cover in the center of the plenum/cover is known to go soft and leak.


I need as much description of the cutting out (Miss? electrical? fuel?) as possible so I can understand what is happening.





George H. and 6 other Hyundai Specialists are ready to help you
Customer: replied 6 years ago.
left u a 5 tip-sensor can be installed backward-without damage to sensor-had broken balance belt-destroyed crankshaft sensor-true problem was a stuck lifter #1-he ran with it backfiring at take off??-anyway job completed-needed lifter and valve job-job completed-also backing firing set crasnkshaft sensor-map-maf sensors p codes all false

Glad to hear you got it sorted out and thanks for letting me know what happened.



Customer: replied 6 years ago.
hopefully u can help someon probably happems a lot when u don't change both beltsgood byelse with problem-from what i could see-

I always change both belts as it is easy enough to do when you are in there, If the engine was sludged then that could be why the lifter failed but I don't see many of those.


Anyway thanks again,



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