2003 Impala with 3.8L auto trans. Out of the blue it started shifting real hard between all gears when up shifting. Acts like it is shifting way early and car jerks and shutters like it does when you shift a manual trans to early. After about 500 highway miles of this it threw a p0742 code. I started manually up shifting and if I run it up to about 2500 rpm before shifting into the next gear and lift of the accelerator for about 1 full sec before shifting I can make it shift pretty smooth. I was wondering if anyone had this before and what you had to do to fix it? I have read some threads on the p0742 code but did not see anyone exactly describe what I am experiencing. Thanks.
Your TCC(torque converter clutch) is stuck on. You have to get it fixed whether its a bad solenoid or a bad wire. If it is not repair you will lose your transmission. All I can say is bring it to a shop if you do not have access to diagnostic information. I would hate to lose a 3k transmission over a small problem.
Normally yes but that's what a code P0742 means. Maybe it's an intermittent stuck condition. Like when it calls to command the TCC to release and it doesn't. Could be a bad wire or like I said a stuck solenoid. I doubt the Torque Converter itself is bad.
Does it all the time since it first started. I followed this youtube video https://www.youtube.com/watch?v=Vel2mF2-So4&index=1&list=FLzLAp_5GM8ONGWGK4Cv9zOQ
for code P0742 and I had voltage at the "U" terminal with the harness unconnected and connected with the key on. Could not do the startup test as my car would not start with the connector unplugged. No other codes.
Tried an experiment yesterday. Took out fuse for trans solenoids and tried driving. Car did start ok. When put in drive engine would stall. Actually any fwd gear but 1st seemed to stall engine although I can't remember for sure if I tried 2nd. 1st would stay running but it seemed more like it was actually taking off in 2nd gear as it had less power than it normally did and seemed to go faster than 1st normally would. Anyhow I don't know if this is how a normal trans would act although I would not think the engine would stall in drive. Wondering if anyone knows about this. Thanks.
Just wanted to note in cool weather 40 degrees or so when I slow down and it shifts from 2nd to 1st there is a real noticeable drop in rpm just before it drops into first. It seems to want to almost stall the engine before it struggles to go into 1st gear. Seems to be less noticeable as engine warms up.
I've never pulled a solenoid fuse but I could imagine if the transmission is put in gear with no solenoid to engage that it may stall the car because it can't turn the transmission.
Replaced all 4 solenoids over the weekend and it is shifting normally once again. Not sure which one fixed it. Is there any good way to test them? I took some pictures that I plan on posting here when I get the time. Thanks everyone for your input.:yahoo:
I haven't seen one removed myself, but all solenoids work the same, generally.
If there is a 2 pin connector apply voltage to one and ground the other. You should hear (maybe see..) a click.
I dont know which voltage is required though.. as its computer based. Its either 12 or 5.
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