GenVibe - Community for Pontiac Vibe Enthusiasts

I have a 2009 base with a 2.4L and 5 speed automatic transmission. The original wheels were 17x7. I replaced them with an 18x8. As soon as i drove the car after replacing the wheels i lost second and fifth gear. Second gear does not even show up in the dash display. 5th shows up but it never will shift to 5th. I tried putting the original wheels and tires back on but still no 2nd or 5th which i am not sure how tire size would have anything to do with it. It is not showing any codes related to this. Only code i get is P0328 for a knock sensor. I am kind of at a loss unless the PCU/ECU went bad for some reason. Any ideas or anyone experienced anything like this?
Thanks

Swapping wheels would have nothing to do with the lack of shifting you are experiencing. Have you done any recent maintenance or modifications? Have you checked your transmission fluid level?

P0328 is unlikely to be the cause of the lack of shift. I'd recommend ensuring the knock sensor is good (it's behind the manifold and a bear to get to). If the sensor is good, it's most likely a broken wire on the way to the sensor.

Also unlikely the ECU just crapped the bed out of nowhere.

I haven't done anything to the car other than the wheel and tire change. Without a code i am not sure what to even try. The car still runs fine but obviously going from first to third there is a very noticeable lack of power.

I would say it is likely a coincidence and nothing to do with a wheel swap.

In this context what do you mean by "lost". Do you lose drive completely in 2nd and 5th or does it stay in a higher or lower gear? What happens if you manually shift into 2nd for example. Can you get 2nd back. If you can it is likely a shift solenoid that's gone out and need to be replaced. If not then it could be a sticking valve or one of the components ts that is responsible for engaging in 2nd and 5th like a clutch piston or band is not applying. Potentially many causes there including something broken or a leaking seal not allowing hydraulic pressure to build up.

Unfortunately I only have the repair manuals for the A246E which is the 4 speed auto on my vehicle so I do not have the power flow diagrams and application chart to help diagnose the issue for you.

You could start with the general advice of doing a fluid and filter change - unless one was done recently.

is the outside diameter / height of the tires different from stock?

The car starts out in first then shifts to third then fourth and that is it. No fifth. I can not manually shift to second because it does not show up on the dash display. The car has about 90,000 miles on it. I will try a transmission filter change and see if that helps. I am thinking it is more of an electronic problem but it could probably use a filter change anyway.

The tire diameter is a little bigger. About 28mm. They fit with no issues and seem to ride a bit better.

With most transmissions (cannot speak about yours specifically since the design could be different) manually shifting into a gear is different to shifting into it from "D'. 2nd from "D" is electronically controlled. If you move the shift lever to "2" the second gear is engaged manually using the manual valve inside the VB. In that situation the shift solenoids don't play a part.

A common test with some transmissions I've repaired is to disconnect the solenoid wiring from the ECM and then drive while shifting manually. If a gear is still missing it usually points to a non-electronic issue. Not sure if this test is valid with this transmission. You can check with ATRA or ATSG if they have a service manual for this transmission - or see if the FSM has troubleshooting procedures.

So I would be inclined to rule out an electronic issue if you cannot get "2" by shifting into "2". But I could be wrong since the design may not work that way.