Downshift trouble with automatic Ion

[LadyStone]

Hi! I am in need of some help. I have a 2004 Saturn Ion Level2 with an automatic transmission that I just recently had shipped from the mainland to Hawaii (I had it in Wisconsin for 3 years prior to the move). I have noticed multiple times within the last week or so that when my car is trying to down shift it seems to stick at 3k RPMs or 2k RPMs and I will have to press on the gas to remind it to downshift. Just a little concerned seeing as I'm in a new state and don't want to break down. WHAT COULD THIS BE A RESULT OF?!?!

[Ruley73]

Originally Posted by LadyStone

Hi! I am in need of some help. I have a 2004 Saturn Ion Level2 with an automatic transmission that I just recently had shipped from the mainland to Hawaii (I had it in Wisconsin for 3 years prior to the move). I have noticed multiple times within the last week or so that when my car is trying to down shift it seems to stick at 3k RPMs or 2k RPMs and I will have to press on the gas to remind it to downshift. Just a little concerned seeing as I'm in a new state and don't want to break down. WHAT COULD THIS BE A RESULT OF?!?!

Is your Ion a Sedan or a Quad Coupe? They have different transmissions so that's why I'm asking. The 2003-2004 Ion Sedans have an Aisin AF23 5-speed automatic, but 2003-2004 Ion Quad Coupes have a very failure prone CVT (Continuously Variable Transmission) that doesn't use traditional gears. Some late 2004 Quad Coupes did get the Aisin AF23 transmission as Saturn stopped installing the CVT around March/April 2004 amid the problems.

[LadyStone]

It is a 2004 Ion Sedan

[LadyStone]

Also I want to add my car does slow down its just that the RPMs stick. If that makes sense.

[Ruley73]

How many miles are on the car?
Is your Check Engine Light on? If so, go to your local auto parts store (i.e. AutoZone) to have the codes checked.

Do you notice this when accelerating? I think you meant that the transmission isn't upshifting properly. It sounds like from what your describing it stays in the lower gear longer than normal until you tap the gas pedal. Am I interpreting that correctly?

[LadyStone]

So my car just hit 111K miles and no check engine light on. So I think I have a better way to explain it now that I have drove it more and tried to pin point the problem (sorry I wasn't so clear before). It never happens when I am accelerating/going up hill but I will notice that when I am slowing down/applying the break and/or going down hill my car slows down but the RPMs stay between 2 and 3K RPMs and it will take me either braking or tapping on the gas pedal to get it from "sticking" (if that's the correct way of saying it).

Does this make any more sense?

[Ruley73]

Originally Posted by LadyStone

So my car just hit 111K miles and no check engine light on. So I think I have a better way to explain it now that I have drove it more and tried to pin point the problem (sorry I wasn't so clear before). It never happens when I am accelerating/going up hill but I will notice that when I am slowing down/applying the break and/or going down hill my car slows down but the RPMs stay between 2 and 3K RPMs and it will take me either braking or tapping on the gas pedal to get it from "sticking" (if that's the correct way of saying it).

Does this make any more sense?

Yes, this makes sense. What you are experiencing is generally considered normal operation for the Aisin transmission. It has a feature called "Downhill mode" in which the transmission tries to maintain speed on downhill grades.

The following description is taken from documentation released for GM techs for the Aisin AF33-5 used in the Chevy Equinox. This transmission is a more robust variant of the same transmission used in your Ion (Aisin AF23-5) and functions similarly.

Downhill Mode Feature
This mode is sometimes called auto-grade braking. Downhill mode, similar to the uphill mode, will occasionally cause customers to believe there is a shifting issue with their new vehicle. In downhill mode, the Aisin AF33-5 applies clutches to maintain a constant speed. The customer will feel engine braking, a process that uses the compression of the engine to slow the vehicles descent of the hill along with an increase in engine RPMs. Again, this is normal operation.

GM eventually implemented a calibration that removed the Downhill Mode feature from the Equinox as of June 1, 2005, but they never removed it from the Ion. The best you can do is take your car to a dealership to make sure your Ion has the latest calibration. Changing the fluid would be a good idea too at that mileage. Make sure the shop uses the correct fluid (GM T-IV p/n 88900925 or Toyota T-IV). The use of Dexron VI fluid will cause permanent damage.

[LadyStone]

Ruley73 thank you so much for your help! I feel like I understand completely now what is going on! I will definitely take it in for a maintenance but I will be able to be a little more at ease while driving my vehicle!

Mahalo!