2002 Alero Trans issue, Bangs Real Hard into Drive/Reverse [Archive] - GrandAmGT.com Forum

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mrbreezeet1
09-16-2012, 07:06 PM
I know it's not a Grand Am, but should be same transmission.
I was reading some replies from gectek, seemed to know about these transmissions.
I was told it has the 4T40-E transmission.
Did have Auto zone scan it, but he said there were no engine codes, and I don't know if there scanner reads transmission codes.
I may be able to use a lap top or scanner where I used to work tomorrow night.

This has the V 6 3.4 Liter motor.
just started this yesterday. Went into yard sale, came back out, put car into drive and it banged like hell. Felt like the idle was at 1500 rpm and you put it into gear. (Idle was normal though) Neutral to reverse, bang like hell 1st time, then Neutral to reverse,Neutral to reverse,Neutral to reverse, after that was OK, Then Neutral to drive bang like hell again. was noticeably hard shifting from 1st to 2nd. also. Shut car off, went into store, came out, car acted fine.
Drove a while, same old story.
Pulled over, shut motor off, started back up, was fine again.
Drove a while, started doing it again. Went to eat lunch, came out was OK again.
Did not check trans fluid level yet, need to have jacked up pretty level, and remove plug.
Was reading here,
http://www.grandamgt.com/forum/showthread.php?t=9001
about the IAT sensor and wiring, how ever, I never noticed a CEL. Did not have Autozone check for codes, (I don't have a scanner)
Something about the IAC sharing the 5 v reference with the TPS and coolant sensor, and upping the trans pressure when the wiring was open or shorted.
I was thinking of changing the filter/fluid, but then I read this about the IAC. According to the PO, it was changed "not long ago"
Hard to tell though.

Someone mentioned Pressure Control Solenoid, but another fellow said the 4T40-E transmission does not have a history of bad Pressure Control Solenoid's.

based on this post, I think I threw away $13.00 on lucas trans. treatment.
http://www.jonko.com/auto_repair_for...howtopic=19274
Worked well for about an Hour or better, then started doing it again.

Will try to pull codes tomorrow.

sleepyalero
09-16-2012, 08:23 PM
if the iat sensor is unplugged, it will cause it to shift into gears very roughly. check that.

mrbreezeet1
09-16-2012, 08:31 PM
if the iat sensor is unplugged, it will cause it to shift into gears very roughly. check that.

Thanks,
No, That all seems to be good. Plugged in, and wiring looks good.
Break in wire or disconnected I would think would turn on the CEL. I have no light.

sleepyalero
09-16-2012, 08:50 PM
all sensors for intake plugged in? look okay? thats really all i can think of that could cause it.

mrbreezeet1
09-17-2012, 04:50 AM
all sensors for intake plugged in? look okay? thats really all i can think of that could cause it.

OK I'm going to try and get some trans codes tonight.

mrbreezeet1
09-18-2012, 03:36 PM
Well they let me use the lap top, but I hadn't used it in a while, did not see the transmission section the 1st time the codes came up, I had a bunch of codes dealing with the BCM and the daytime running lights, headlights, parking lights, but all that seems to be working OK.
You had to scroll up in the window to get the transmission entry to show, then expand it.
But like I said I didn't see it the 1st time.
This guy there was trying to say I needed a BCM, but I said it all dealt with the daytime running lights, headlights, parking lights, and they all seem OK.
He said "why don't we clear the codes and drive it"? (I might have cleared a trans code)
So I drove it for a bit, and of course, it would not shift hard.
The boss was wanting to lock up, so I said I would drive it tonight, and scan it tomorrow again.
I drove it almost an hour, and again, could not get it to shift hard.
I will have to put this on hold for a few days, and see if it shifts hard/bangs into gear, and scan it again. When it shifts hard, I try not to put it in gear and make it bang, I can tell it's doing it when it shifts hard from 1st to 2nd.
I will let you know?????