2005 aveo no reverse?

[nails]

Hey guys, new to this site and new to aveo's but was hoping you guys might be able to help me or point me in the right direction. I haven't had the aveo for long but everything was working perfectly until the other day when I put it in reverse and it just revved up and didn't move so i put it in park and back in reverse and it worked fine for a while but now when i put it in reverse it just revs up and dosen't move. It drive forward just fine no problems and it isn't throwing and check engine codes, I have a bad feeling its the transmission but before spending a bunch of money to take it to the dealer i was hoping someone had some other suggestions to try. Any help is much appreciated.

[slayerized6]

Auto transmission? Might be a bad solenoid.

[nails]

Yes it is an auto transmission, I was also wondering if it was the reverse solenoid but not sure how to test it.

[avguy]

First thing to do for any A/T issue is to check the fluid level and quality - did you do that? Next, is everything working properly with the forward shifting, including torque converter lockup? If so, check for a bad PNP switch or linkage issue first. One red flag for an issue there would be if the reverse lights aren't coming on when shifted into R. The Aveo PNP switch is well-known to fail and cause issues with P, but perhaps its possible that problems on the R side might show up first.

If everything is ok with PNP and linkage, then disconnect the TCM connector to see if it will reverse with the tranny in limp mode. If it does reverse in limp, then it's certainly either the shift solenoid, TCM, or one of their wiring/connectors.

If none of the above stuff leads anywhere, you're probably looking at an internal transmission issue. Best at that point to visit a transmission shop to have the TCM scanned for codes, and pressure testing done, in order to attempt to diagnose the exact problem and corresponding estimated cost to repair.

[nails]

The fluid level is good and the fluid looks nice and red and doesn't smell burnt. The linkage seems to work ok, it goes in drive and all other gears no problem. The reverse lights do come on, but other than that not sure how to test pnp switch. I will try to disconnect the tcm connector and try that, is that the plug on the side of the transmission under the master cylinder?

[avguy]

Reverse lights are switched on via the PNP when the shift selector is moved to R, so that being the cause of no reverse is out of the mix. An issue in the remainder of that circuit (going to the TCM) is possible, but would be a real long shot. However, I do recall someone a while back posting that the TCM connector in their Aveo had become corroded, so that's something to check as well. My '05 is a standard, but IIRC, the TCM on my daughter's '06 is located next to the brake pedal assembly.

[nails]

Well I unpluged the tcm and still no change, and the connectors all look good. Could it still be the solenoid or tcm?

[avguy]

.... Could it still be the solenoid or tcm?

Yes, but the solenoid (which is actually 5 individual/separate solenoids) is located in the valve body, so only the TCM is a routine DIY. You COULD try just hanging on a boneyard TCM, but I'd try scanning for TCM codes before doing that if it were mine. If you decide to have it scanned for codes, disconnect the battery first in order to get a clean slate.

[nails]

Thank you I will try to find a shop to scan the tcm, I will let you know what i find out.