A few months ago, my brother's '05 Pursuit began to have some automatic transmission slipping.
To give you an idea of what's happening, it's as if the car struggles to find the right gear typically between 1st-3rd. If the car is recently started and is still "cold", it struggles to get into the right gear. It has problems going up hills when "cold" and feels like it can't catch the right gear. When accelerating from a light at typical speeds, it can feel just fine and transition from gear to gear nicely, but sometimes it sticks in 1st too long, then slips and the revs spike and then it finds second gear. If you accelerate fast/hard either from a light or when attempting to pass like on the highway, it'll slip trying to downshift then spike the revs at the point it should change and sometimes go back into that gear or find the next.
At first he took it to his mechanic who performed a transmission service. This didn't help. He then picked up a transmission from a scrapper with low milage and replaced his original with this. This hasn't corrected the problem either which leads me to believe that it wasn't the transmission to begin with.
It's never thrown a CEL code during this period of time.
My suspicion is that it's an ECU problem. I've been told I can replace the ECU and have it re-programmed at a GM shop.
Can anyone offer some advice as to what they suspect is going on?
2005 Pontiac Pursuit (G5)
Saturday, December 8th, 2012 AT 6:38 PM