What is wrong with my car?
I have a 2003 Nissan Altima 2.5 S with approx. 78,000 miles on it. Periodically, while driving on the freeway or on city streets, it begins to jerk and the RPM gauge goes crazy for a second. Any idea what this problem could be? When the mechanic drove it, it didn't do it. The check engine light is not on. I thought it might be bad gas but I put in Chevron gas and it still did it. Any ideas on what it could be? I contacted Nissan and they said that a recall had not been performed on my car for the ECM. This will be performed in the morning. When I spoke to the mechanic, he said that wouldn't be the cause of what I'm describing.
The ECM recall could very well be the problem. If the "flash" for reprogramming the ECM corrects it, problem solved. If not, it sounds like you may have a throttle position sensor going bad or other engine-related sensor causing a glitch. I really believe the ECM reflash may fix it.
Do the gauges and lights flash on and off when this occurs? If so its definately an electrical issue. I woud start with the ignition switch. Your engine is a qr25de and its a drive by wire throttle system. Or in other words your throttle is controlled by a wire and not by your foot. So its definately an electrical and not mechanical issue I would think. I would agree with checking out sensors. Although if a sensor were failing it would most likely set off a diagnostic trouble code. Check for loose electrical connections under the hood.
It sounds like a cam or crank sensor. The ECU monitors the signals to adjust ignition and valve timing, as well as provide an RPM reading. If the dealer tech says the ECU flash won't fix it, that's because that campaign was issued to correct a different issue that you may not have experienced. When manufacturers issue a recall/campaign, the symptom being corrected is stated in the paperwork the dealer receives, so the tech can tell you if it is the fix or not.
i worked at a local nissan dealer and from wat you are describing the prob is the ECM so the relearn should fix your problems