# '07 Sentra drove through water; Mechanics puzzled



## MySentra07 (Dec 8, 2014)

Roughly three months ago, I was forced to drive through deep water in my 2007 Nissan Sentra. I made it through, but the Check Engine light came on almost immediately afterwards. The interior floors were soaked, as well. I got the ball rolling towards having my insurance company and a mechanic checking the car out, and went to the local Auto Zone to have the codes read before taking it into the shop. The car showed codes for issues concerning the TCM or engine speed signal circuit, and the air/fuel ratio sensor. All the auto shop did initially was to change the oil and the air filter, which I could have done at home. Within days of leaving the shop, the warning light was back on. I went back to Auto Zone and the reader brought up the same two codes. I showed these to the mechanic, and their solution was to change the car's throttle body. That didn't solve anything, as the light was back on again soon enough, showing the exact same two codes. Now the mechanic says I need a new air/fuel ratio sensor, but that the insurance company won't cover it because the problem likely wasn't caused by the water. I disagree, as that code's been showing since the day of the incident. And what of the code for the TCM/speed signal circuit? Can anyone offer me any information or advice on this nightmare scenario?!


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## smj999smj (Jan 1, 2006)

What I would be concerned with is water getting into the harness connectors and corrosion issues. Rather than just replace the air/fuel ration because that's the code that is being triggered, I would perform resistance and continuity checks on the circuits, which is what one is supposed to do if they are following the diagnostic procedure for the given code rather than guessing. Now, I'm not saying they didn't do that, but I wouldn't be surprised if the didn't, just based on my experience working in both independent shops and Nissan dealers. Now, if water got into the vehicle, my suggestion would be to get rid of it. Flood cars tend to be nothing but problems afterwards.


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