Cosmo Kramer

My 2011 S with 130,000 miles on it has an issue in the cold weather. Upon startup, the transmission hesitates when shifting from R-D. When taking off from a stop acts like it is in neutral until the revs build a bit then slams into gear and takes off. Once I have driven a few minutes and the transmission warms a bit its fine, at fully warm it drives 100% no issues at all. The colder it is outside the worse the symptoms are. Today it was very cold, -20 deg C and it was bad for the first 15 min.

I have verified the transmission fluid to be correct and scanned the transmission for codes with my Durametric and there is nothing. Once the outside ambient temperature goes above freezing these issues on initial startup go away. I am wondering if someone previous to my ownership put in the incorrect spec fluid and the flow characteristics when cold are causing issues.

Any other ideas?

deilenberger

That sort of symptom is usually low fluid level in the transmission. When the transmission is cold the fluid will decrease in volume, but it would surprise me if it was enough that it would cause these symptoms - if the fluid level hot was correct.

When you checked the level - did you check it at the specified temp, after running the fluid up to hot and allowing it to cool down to the specified temperature? Do you know if the fluid has ever been changed? While Porsche calls for it at 160k miles, most people seem to do it before 100k..

chsu74

I have your exact symptom and at 64K miles. It has happened ever since owning the car at 51K and 3 years ago. My OBII reader calls out a "aux transmission fluid pump stalled" code but nothing pops up when read by PIWIS.

Cosmo Kramer

chsu74

I had another incident where lightly braking on the highway so the torque converter disengages and then will not engage until you rev the accelerator into very high rpms.

Also a common symptom is braking lightly on a hill with the hold function on. It will buck every now and then like the torque converter engaging while car is completely stopped. If I did not have the brake on, it would hit the car in front of me.

Quadcammer also experienced this when he borrowed my CD for a few weeks this past summer.

jtakhtalian

I don't know the details but I remember having previously seen a Porsche Recall titled WF52 - Transmission Pump Recall. I never did get much more info other than it had shown up on a 2011 Cayenne's CarFax report. Here's a pic of the CarFax report with the recall info. Perhaps your dealer can offer some info that might help shed some light on whether there is a relation.

chsu74

Thank You!

Cosmo Kramer

Just a thought here. I am wondering if a weak battery could cause the issue. I know mine doesn't have much life left.

chsu74: How old is your battery and what is the floating voltage on a cold day?

chsu74

I am not sure about my battery life. I travel quite a bit and do plug the car in if the car does not get driven in one week's time. I have not been able to get the voltage show up on the Cayenne like other folks on the bottom of the PCM. There is no option for me and its frustrating but I also have not seen it on other loaners so dunno..

Cosmo Kramer

My understanding is the auxiliary pump is activated with the start stop system but maybe it is used at other times as well. It is electric and I know low voltage can cause these cars to do really wonky things.

chsu74

My '13 CD do not have a start and stop system. There are stuff that popped up on google but I don't think anyone definitively knows.

edde

I mentioned what feels like a sloppy torque converter when I bought this S last January. Nothing as dramatic as a slip tho. But on flat ground when the car won't crawl forward it'll take a moment to engage and it can be a hard sort of hit.. I also have had just a few occasions where it will surge forward as I'm coming to a stop. Aside from that sometimes a hard or sloppy downshift from 3rd to 2nd and I feel like a delayed downshift on the highway when I get on it - I'm watching the road so I'm not sure if it's trying to drop 2 gears at once but I think so.

I mention all this because of this report I found after state safety inspection in December. No one mentioned it but I found it on my icarscanner. I've talked to a local mech who wants to drive it and then see what he can find. As soon as I get a break in the weather I plan to go see him.

Here's the report. My scanner reports no DTC's related to Triptronic. My battery is less than a year old, but the car doesn't seem to know that from the scanner. Voltages seem normal though. Start stop works. FWIW.

deilenberger

The voltage can be displayed on the multi-instrument-display section of the instrument cluster. It does not show up on the PCM. It's a selectable line item for the MID.

chsu74

Got it. Thanks. Its at the instrument display field 4 line option instead of the top or bottom display.

deilenberger

Actually - if you look at each line, it can be on any of the 4 programmable lines. Mine is:

Line 1 - Boost
Line 2 - Compass
Line 3 - Voltage
Line 4 - Telephone (which is rather redundant since that also does display on the bottom of the PCM display..)

BTW - there are more choices for each line you have to scroll down on the selection menu to see them.. And to get this to stay how you set it - press "Set" on the door memory, then set #1. Then when you stop the vehicle, lock it using the key (button) you want it to be remembered on.