Questions and Answers

Nissan Sentra Sudden Acceleration Q. I have a 2002 Nissan Sentra GXE with a 1.8 litre engine and 4-speed automatic transmission. The car also has air conditioning, power rack-and-pinion steering and cruise control. No ABS, just standard power brakes. The car currently has only 13,000 miles on it.

I have had the car for 1½ years now (bought it new). I have had no problems with this car until now. In the last month, on a totally intermittent basis, I've run into a sudden acceleration problem on 5 or 6 occasions.

I've taken it to a Nissan Dealer twice to have it checked. No trouble codes have been registered or found. The Nissan dealer lubed and adjusted the throttle cable on the first visit and ran an "idle air learn". The problem reoccurred anyway. I took the car back, they did more checking but found nothing and referred it to Nissan Consumer Affairs and Technical Assistance.

I asked the dealer if they had checked the cruise control and they stated that shouldn't be the cause of the problem unless it's on at the time the problem appears (which it is not). The cruise control seems to operate normally on the highway when engaged. However, my research indicates that all auto manufacturers have had sporadic problems with their cruise controls causing sudden acceleration and the solution is to replace the cruise control module even if no codes are stored.

I live in Ohio and we had a very rough winter this past year. Salt was used on the highways extensively. Perhaps hidden corrosion or a bad sensor or circuit board is the cause of this problem.

Specifically, the problem occurs when decelerating to a stop. The car will all of a sudden buck mildly once or twice and then the sudden acceleration begins with engine rpm's reaching 2,000 to 3,000. It is resolved by either putting the car in park (automatic transmission) and then the engine rpm's readjust themselves to normal or by turning off the engine and then back on. Repeating the problem on demand is not possible.

Have you heard of any cases such as this? Any ideas on what may be the possible causes? Any possibility it is in fact the cruise control module even though the cruise control is NOT activated at the time? Is the EGR system a possible cause as well? What should be done to help diagnose this, disconnect the cruise control for awhile and see if it stops?

Is there something that the dealer may be overlooking? Everyone seems to be at a loss as to what is causing this. This is frustrating and dangerous. I fear driving the car because you cannot predict when this sudden acceleration will occur again. Please help. Thanks a million

A. Sudden Acceleration Syndrome (SAS) has been something that has plagued all car makers for many years. In fact, the current shift interlock systems, where you need to depress the brake to shift out of PARK, was born to help prevent SAS.

Shifting into NEUTRAL or PARK will cut the cruise off, so my gut feeling is that it may be related to the cruise control system. I would disconnect the cruise control cable at the throttle body and see if the problem goes away. If it does, then you know it is the cruise control that is the problem.

Loosen the lock nut and slide the cable out of the bracket. Then open the throttle to full open and remove the cable end form the throttle drum. Put the cable back in it's bracket so it won't flop around and get tangled in anything.