Nissan Repair: Xterra Transmission, knock sensor, dash panel

Question

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-----Question-----
I have a 2000 Xterra V-6 3.3liter, The SUV was running a little rough so I took it in for a tune-up and since it had a little over 100k I had the timing belt,water pump and thermostat replaced along with a tune-up.
A couple of days after I got the car back the transmission started acting up it would shift real hard into second gear and would not shift into overdrive and if you take your foot off the accelerator it feels like the transmission goes into neutral.  When you turn the key on the overdrive light on the dash panel flashes and the check engine light comes on.  My mechanic ran a code and came up with 475 I think?? solenoid A and also a knock sensor.  I have had the car for about two years 50k and have never changed the filter.  could this be the problem.  Thanks for your help.

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Addis,

I hate to say it but the code is correct and that is what the transmission does when the solenoids act up.  I would hope for the best and have it replaced along with a fluid and filter change.  Nissan has a good software program that limits the damage to the transmission when things screw up so lets hope no clutches or bands got cooked.  But, take it in pronto.  The knock sensor is a common problem with your year model.  I have seen more than I care to.  The transducer goes bad inside the sensor and it has to be replaced.


Von,

My mechanic replaced the solenoids and fluid and filter and it appeared to fix the problem but only temporarily. He drove it for about 20 miles and it started doing the same thing shifting hard into second and would not go into overdrive.  He had cleared the codes before driving and they came back clear (except for the knock sensor of course). When he returned and the transmission was acting up again he ran another diagnostic and it came back with C5 and B2 as well as the 475 or 745?? I cant remember which it is.  The C5 and B2 came up original but he was unable to locate what these codes meant. Could they be the problem and what do these codes mean.  He said the inside of the transmission looked good(as far as no metal shavings in the pan or on the magnet).  Again thanks for your help.

Addis  

Answer
Addis,

THe problen is two fold.  First, the usual problem is the computer that controls the solenoids and if that does not correct the problem then you are looking at the solenoids.  Have him check the transmission shift computer for proper function and go from there.