QuestionHi, I have a 2006 Nissan Sentra with 39,000 miles. Up to this point, I haven't had anything wrong with it. On Sunday I went to pull out of my driveway and as I rounded a corner the "service engine soon" light came on and when I pressed the gas nothing happened. It could rev in neutral to about 1500 rpm but basically after 30-60 seconds in gear, I was riding on only momentum.
I had it towed to the dealer and they checked it out. They said it was not the fuel pump, which apparently had a recall on it for my car, and told me I had to replace the electronic throttle sensor and air filter. They also recommended air-cleaning the throttle body, which I declined.
I drove the car back last night, and had 40 miles on it since the repair when I pulled into work this morning and the exact same thing happened - engine light came on, and the acceleration was nonexistent.
I had it towed back to the dealer, and they're "working on it," but right now I'm out $250 and scratching my head. Any ideas as to what could be going on? Help is much appreciated!
AnswerHi Will,
Without actually looking at it, everything is a guess. All things being equal my best guess would also be the TPS (Throttle Position Sensor) However, I believe your vehicle incorporates a DBW (Drive-By Wire) system which would lead me to believe either the PCM is having a fault reading/controlling the throttle body or the throttle body itself is going bad.
You can try doing a wiggle-test whereas you start/idle the vehicle and without breaking them, wiggle the wire harness and the connectors to the throttle body and observe if any of them trip the MIL (Malfunction Indicator Lamp). If it does, then a bad connection and/or bad sensor or wire will be the cause. If not, I'd still lean toward the throttle body unit itself.
Next time the fault occurs, with the engine idling, have a friend push the throttle and observe if the throttle plate moves at the same time. I'm sure that even with a bad TPS the engine speed will still increase, albeit a bit rough, but it should still operate above 1500RPM.
What codes are being displayed?
Looking for a reputable service technician? My advice on finding a good technician is: Steer clear of the dealership and 'chain' stores like Firestone, Sears, Pep Boys, Monro Muffler/Brake, Midas, etc. as they usually only employ ONE ASE Certified Tech just so they can say they do and chances are, that guy is the asst. manager or manager and is not in the store to diagnose/repair vehicles anyway. Find a service location in the link below or get some names out of the yellow-pages and do a drive-by. Garages that employ ASE Certified Technicians will be marked with the 'Blue-Seal' insignia. If unsure about whether a place employs Certified Techs, just ask to see their credentials. ALL ASE Certified Technicians will be PROUD to show and display their certificate(s).
Thanks for the question, I hope this information was helpful to you.
Fred
Knucklebusters Used Auto & Truck Parts, Inc.
www.knucklebusters.us
570-453-0910
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