tranny shifts hard (sometimes)- 2001 olds alero

[heather1511]

ok here goes....the trac off light, svc vehicle soon, and brake light came on and then went off. it comes and goes but latley the tranny has been shifting hard into first gear (only sometimes) I have had it to 3 shops and nothing is reading on the scanner. I had the hub assembly changed because of the light issue before but i took it in the same day they came on so im not sure if the tranny would have shifted funny then. I called the dealer and told them what was going on and they said they would scan it for 90.00 but if nothing came up then i would have to wait until something did, where do i go from here? by the way i just had the speed sensor or some sensor changed a few days ago and that didnt help, it was by the engine i think

[lebky]

engine size and year would help , anyway if you have 3.1l 96-98 check vacuum modulator, and vacuum lines going to vacuum modulator from the intake manifold. You can use vacuum pump and aply about 15 inHG to vacuum modulator see if it holds the vacuum if not replace it. You can check if any oil drips from the vacuum line connection if you do not have a vacuum pump. If you see any oil modulator is bad.

[heather1511]

oh yeah sorry--2001 olds alero 2.4

[xeroinfinity]

Welcome to AF heather1511.

THe only way you will find out whats wrong is with the proper scan tool. Most part store scan tools dont read ABS or B & U codes. This requires a GM Tech II scanner or other equivalant.
Then after the repairs are made the scan tool is needed again to clear the codes.

Hope that helps.