Nissan Xterra Forum : “2004 V6 Xterra speedometer / engine issue”
2004 V6 Xterra speedometer / engine issue
We bought a used 2004 V6 Xterra with 70,000 miles last year. The car normally runs well. But occassionally (maybe once a month), the speedometer & odometer both stop working while driving down the road. The engine keeps running, but the car is completely unresponsive to the gas pedal -- it slows down to 0 even when pressing the pedal to the floor. After 30 or 40 seconds, it returns to normal. But once this starts during a driving trip, it keeps repeating the off/on pattern until I park the car for a while. Then it'll act normally for a while until it happens again. The local Nissan dealership doesn't have a clue, even after hooking it up to a diagnositic machine (came back clean). Any ideas on what the problem is, or what I can tell them to check?
If you say it's effecting your tach and speedo so they just go 'dead' and the needles go to zero, when you are still rolling along, and the engine dies or simply goes to idle, that would sound like the main ECU, or Engine Control Unit. It is responsible for both the gauge display information and the engine/injector control.
If it's something that you can trace to:
a) after prolonged running
b) hot weather
c) heater on
I would suggest that it's temp related and the ECU is overheating inside. It could be something as simple as a bad solder connection that opens up as it heats up and things expand.
If it's more something that happens when it's damp, raining, or after a wash, then I would suggest a connector that is allowing water in and possibly pulling down the power supply so the ECU craps out. But that is less likely.
Either way, it sounds like it's electricl. Since it's the engine and the gauges, it sounds like the ECU.
Best of luck!
I dont think it's an electrical problem, because the computer would have read that theres an electrical problem. You might wanna check to see if the accelerator and that section of the engine is fine, simply because all three of those (tach, speed, and gas) dont respond all at the same time.
it is definate that it's a compute problem. Many of todays OBDII diagnostic systems do not store temporary info if what is occuring does not fall out of the 'normal' range. I've dealt with a few Nissans and the TCM (transmission control module) and ECM/PCM (engine control module/powertrain control module) communicate together to produce the signals needed - if one fails, the other uses 'default data' to continue doing what it 'thinks' is right and does not set any codes. the only real way to have it checked is on one of your trips - when it starts acting up, take it to a dealer and have their shop forman drive the vehicle. don't shut it off as any info that is stored will likely be lost. Also, you could see if a 'data recorder' is available that they can give you to record data as the problem happens. many manufactures have this available, not sure if nissan has it or not.