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Discussion Starter #1
Just wanted to throw this out there to see if it is just me being paranoid or if there's actually something going on.
I have a 1500 high roof and have it built out into a partial camper (basically I have bed and battery bank, a removable kitchen but I can still carry sheets of full plywood). I live in CO and I know some of the passes around here are pretty burly.

1. Automatic Shift Points: When going over some passed my tranny runs super rough. I'll hit an incline and it will automatically downshift. This is normal, but once it levels back out it will stay running at 5,000-5,500 RPM's for 20-30 seconds. I've only had this van for 3 months now but this seems odd to me. I've never had a vehicle that runs this high of an RPM before it shifts? Any thoughts from anyone.

2. Descent Control: When going downhill the van will automatically downshift to reduce the wear on the brakes. In the past I would sometimes downshift when going down super steep hills or around corners but the amount that it does it in the van seems excessive. I'll be going down a hill going 60 and it will drop gears and drop me down to 55. I don't really understand this, only because some of tis time I want to be going 70. I've tried shifting into the Manual drive, but there's no way to override this. If I try to shift up, it won't let me. Is this just how this transmission is designed and does everyone deal with this?

3. Engine Lights: I keep getting 3 lights coming on: 1) I've had the hazard looking light on the dash come on a few ties this summer and the dash will display "service parking assistance". It will stay on until I turn the car off and back on. 2) Check engine light throwing code P0335, which is the crankshaft position sensor. 3) Going over any big passes the E-Brake light will come on and again stay on until I restart the engine. Does anyone have any information or tips on these? I've called the dealership and asked them about them but the response is always "you can bring it in but there's really nothing that we can do unless the lights are still on when t shows up here" This really doesn't do me any good unless I make it 2 hours to the nearest dealership without turning the car off.

Overall love the van, and been loving the camping trips and how fun it is as a daily driver.

Thanks in advance,
Andy
 

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Gas or diesel?
 

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In mountains this summer the downshifting happened more often when the cruise control was on.
It was much less when the cruise control was not only disengaged but turned off. FYI
 

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I did some serious mountain climbing this summer in Colorado and Utah. The biggest thing I don't like is when in manual mode it will still do the crazy downshift. Don't like that at all. There's going to be lots of failures with this transmission when mileage gets high. It has to shift way too much. My trip was just shy of 6000 miles and I thought the tranny went through ****. On my return home to FL, came across I10 doing 70 and van was shifting constantly on the rolling hills. I slowed to 68 and put it in 5th gear just to keep the shifts down, and this is Florida, not exactly mountainous. I think the gear ratio should be lower.
 

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The programming on the trans is such that it loves to downshift going downhill. Cruise exacerbates it, and tow haul also makes it worse. Both my pms do this and neither has anything wrong with the trans. Its just a programming (or lack thereof) choice by the engineers.

Yours may have something actually wrong. The dealers line is complete BS because all codes will be stored in history, along with freeze frame data when they triggered.

There is nothing "special" about the pm gasser that requires you take it to the dealer. Any decent modern independant mechanic has all the tools he needs to diagnose it. Id take it to one of those guys, and at least he can steer you in a direction. Or find another dealer, prefereably one who doesnt think brake codes are ignorable.
 

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Discussion Starter #7
Thanks guys. I guess all along it was just me, I'll try to find someone local that can take a look of it.

Sent from my SM-G930V using Tapatalk
 

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1 and 2 are normal, 3 is not but certain active or pending codes could cause the powertrain to go into some sort of "safe" mode to protect itself, which can have the symptom of odd gear shifting (being in the "wrong" gear, etc).

The engineers are not necessarily crazy to have programmed the shifting the way they did. I can see their rationale even I don't necessarily fully agree with it.

(1) is to avoid "gear hunting". If it commands a downshift due to an incline, it delays the subsequent upshift until the load on the engine is light enough that it won't "hunt" between gears. It avoids this behaviour of some old school automatics: Bog down in top gear due to not wanting to downshift until almost full throttle in the too-high gear, then drop down a gear and take off for redline at full throttle, then back off the throttle and upshift, thus leading to bogging down in top gear, rinse and repeat until you get to the top of the hill.

(2) is to avoid inexperienced drivers - and there are plenty of those! - cooking the brakes on long down-grades, or having the vehicle feel like it is "running away". Cooked brakes to the point of having no brakes is recall or lawsuit material in this day and age. The way it is, is the way it's gotta be to avoid that. Personally I'd have only activated this logic in tow-haul mode or on cruise control, OR delay the downshift until the driver actually applies the brake pedal.
 

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So it sounds like the shift points are not adjustable. Is that correct?

If true, I can live with it, but it's pretty annoying.
 
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