# Crankshaft, Camshaft, O2 sensors replaced, SES light is on



## mongepor (Dec 9, 2014)

Hi,

I have an 2004 B15 Sentra, recently the SES light turned on, the scan said it was the Crankshaft sensor.

The mechanic replaced all the Crankshaft, Camshaft, O2 sensors one was Nissan original and the other two BOSH, just after one month or so the SES light turned on again, we scanned it and the same error code.

Why if the sensors are brand new and good quality the same error code will come up again in just a short time?

Thanks


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## smj999smj (Jan 1, 2006)

You are assuming Bosch is good quality? Sometimes....sometimes not. Not sure why an oxygen sensor was replaced for a crankshaft code? It's possible the new part failed. Usually when I replace cam and crank position sensors on these Nissans, I use the "sensor kit" which was originally put together for the recall. Non-Nissan sensors have had a poor history on these engines. Also, if the sensor kit was used, the cam and crank sensors look the same except for a white paint dot; the one with the paint dot is the crank position sensor. Also, just because a diagnostic code triggers for one particular item, it's not necessarily that item that is faulty. Trouble codes are only designed to put the technician in the right direction. Once the code is retrieved, there is a diagnostic procedure in the service manual for that particular code which most be followed to isolate the exact cause. Perhaps the sensor is not bad, but the circuit. I had a QR25DE Altima that triggered a cam position sensor code and the owner installed a new sensor. Six weeks later the car shut down and triggered the same code. It turned out there was too much resistance in the sensors ground circuit. There is a component test you can do on the sensor. Specification will vary depending on whether it's a Hitachi or Mitsubishi sourced sensor. The resistance is checked using an ohmmeter at approximately 70 degrees F. The problem is, that the sensor may be fine at room temperature, but will start to breakdown after it gets hotter, as when the engine has been driven for 20 or so minutes.


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## mongepor (Dec 9, 2014)

Hello smj999smj,

I hope that you see this message, it looks like you know what you are talking about so I want to post an update on my situation.

#1 I am in Costa Rica (Central America) I believe the car was brought here from US.

Yesterday the mechanic scanned the car once again, and everything was looking good, he said that even the scan is showing the camshaft position error (the sensor in the top left side of the engine) the car seems to be working perfectly.

The crank and camshaft sensor were replaced with Nissan genuine sensors bought here in the Nissan store.

The mechanic tested the voltage and it was good, so he recommended me the following:

To put back on the old camshaft sensor in order to test the voltage. He believes that the sensors sold in US work with different voltages than the sensors sold here in Central America and that may be causing the SES light to turn on.

Does this sounds right to you?

Yesterday he turned off the SES light but it turned back on withing less than 10 miles 

Thanks for you help, the SES light is driving me crazy.


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## smj999smj (Jan 1, 2006)

I'm not an expert on non-US Nissans, but it wouldn't make sense for Nissan to use different voltages based on region. Also, keep in mind that Nissan does have a plant in Mexico that ships cars to the US. You can tell where the vehicle was manufactured by the first digit of the VIN #. US VINs start with "1" or "5," Mexican Vins start with "3" and Japanese VINs start with "J." They do use two different brand sensors, Hitachi and Mitsubishi, and they do have different resistance specs, but the sensors, themselves, are interchangeable. My advise is still the same: refer to the Nissan factory service manual for your vehicle and perform the diagnostics for the code that was set. You can get downloadable service manuals online; you need the "EC" section of the manual. NissanHelp.com has manuals in their "knowledge base" section and Nico's website also has them.


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