I've noticed something new in my 2009 (just turned 61,000 miles). When on the highway on cruise (65 - 70 mph) in 6th gear, as I begin a slight incline, the car will make a momentary minor "jerk" and I can see the needle of the Tachometer twitch just a bit. If I don't address it - it'll continue - and sometimes it'll downshift on its own.
This never happened before, but is fairly routine now. Mind you I'm not towing, the car is essentially empty, no apparent head wind.
I've begun to drive on longer highway trips in "manual" mode in "6", and as I approach an incline that I suspect will induce this twitch - I manually down-shift to 5th - and no more issue. Perhaps a component has begun to wear after 60,000 miles... but I never had this issue in the previous 9+ yrs.
Can you share more details (part #'s, etc.) about the little plastic discs and seals?Based on other posts on delayed shifts, I ordered the parts and spent a saturday to replace them. Little plastic discs ($34) that wear and tear.
$107 total with trans fluid and seals.
https://www.acadiaforum.net/24-engi...lace-tehcm-tcm-transmission-module-p0752.html
Sonnax Pressure Switch Installation Tool Kit - 124740-TL30Can you share more details (part #'s, etc.) about the little plastic discs and seals?
First, I am not a mechanic. My car is a 2012 (purchased in late 2012) with about 107K miles. In great condition cosmetically but with some "old age issues'. I noticed the shuddering, jerking, skipping, quick hesitation at about 106k, about 1-2 months ago. It happens going up small inclines, on flat roads, highways... at any speed and Usually once in the AM and maybe PM. In late December, I needed to change the SPark Plugs and the Water pump ( I had an ongoing leak for about 2 months). My next fix, part of the "annual physical on my car" would be a transmission flush just due to the miles. My aim is to be preventative and plan out potential cost. But I called a mechanic today to find out about the "shuddering" and his 1st thought was transmission. We schedule an appt for Friday with a stop at transmission person. On my way home tonight, the shuddering/hesitation feeling happened many times. My car felt a bit sluggish also. I have no warning light. On some occasions (2-3 times a month), there is a burning smell which I have smelled for years and the dealer could not ID the problem. If it happens to be a transmission issue, would a transmission flush fix the problem. New transmission is definitely not part of my plan. Thoughts?Just bought 2012 gmc acadia with117k on it. Mint cobdition cosmetically and seemed to drive fine untill yesterday. It seems when im doing about 40 mph or 60 mph the rpms drop betweem 1700 and 2100 and i get the shudder/buck. If i let of gas or accelerate it powers through but when in steady speeds in traffic it gives those issues. Let me know what you think? Ive read several posts here that start with a lot of minor work and end withtorque converter. Hope this isnt the case.
Start by checking the transmission fluid level/condition and clear the code. If it's good and the code persists, the problem is deeper. This article should give you some idea of what possible repairs are necessary: https://www.autoblog.com/2016/09/14/p0989-obd-ii-trouble-code-transmission-fluid-pressure-sensor-sw/My 2008 does this exact same thing. I got my computer scanned and it said P0989 "Transmission fluid pressure switch 5 circuit low voltage." Any ideas how to fix?
I have a 2012 and have replaced all the coils and plugs the purge valve the MAS sensor and had the throttle body cleaned and still have the same problem that hesitation will drive you nuts I’m no pro but I’m thinking this whole problem is the torque converter good luck with yoursJust bought 2012 gmc acadia with117k on it. Mint cobdition cosmetically and seemed to drive fine untill yesterday. It seems when im doing about 40 mph or 60 mph the rpms drop betweem 1700 and 2100 and i get the shudder/buck. If i let of gas or accelerate it powers through but when in steady speeds in traffic it gives those issues. Let me know what you think? Ive read several posts here that start with a lot of minor work and end withtorque converter. Hope this isnt the case.
I recently had this same issue on my 09. in my case I changed all the injectors, sparks plugs, crank shaft position sensor, shock sensor, fuel pump, fuel pump control module and coils. And nothing changed. But it’s all came down to a minor issue. The green colored rubber ring/seal on the pcv situated on top of the engine was worn out. And finally when changed the engine runs mints and no more shuddering.Just bought 2012 gmc acadia with117k on it. Mint cobdition cosmetically and seemed to drive fine untill yesterday. It seems when im doing about 40 mph or 60 mph the rpms drop betweem 1700 and 2100 and i get the shudder/buck. If i let of gas or accelerate it powers through but when in steady speeds in traffic it gives those issues. Let me know what you think? Ive read several posts here that start with a lot of minor work and end withtorque converter. Hope this isnt the case.
