Tcu codes, bouncing needle

[chet1185]

I've used the search and didn't locate anything really.

When i went to look at the gst we are going to buy, i used my analog meter set on 10 dcv. The needle just kept going all the way up then right back down. Just kept doing that. Does that probably mean the tcu is bad? The guy says the car has all gears sometimes and others only 3rd. Any help is appreciated! Sorry if i should have search more or tried using different words.

 

[DSM1G90]

Set the VOM to a higher VDC value so the needle won't peg over all the way. The pulses are 12VDC.

 

[chet1185]

So pretty much i did it wrong?

That sucks because the car is an hour away from me. I thought i was doing it right.

 

[knochgoon24]

Those pulses are what you are counting. Each long pulse is a 10's digit and each short pulse is a 1's digit. If it pulses steady, there are no codes present. You aren't looking for an exact value on the voltmeter.

 

[chet1185]

Ok. So it just constantly bounced. That doesnt mean the tcu isnt bad right? It wont set a code for itself correct?

 

[DSM1G90]

Constant "bounce", which are only short pulses, should show a normal operating unit.

The long swings followed by short swings of the needle is the code.

You count the long swings, then count the short swings, like 4 then 1, gives you 41 which is a Fuel Injector issue.

 

[Phantom DSM]

Constant "bounce", which are only short pulses, should show a normal operating unit.

The long swings followed by short swings of the needle is the code.

You count the long swings, then count the short swings, like 4 then 1, gives you 41 which is a Fuel Injector issue.

Code 41 is an Ecu code for engine diagnostics. The OP is discussing TCU codes. Auto Transmission codes are retreived as shown by link below. Long and short pulses combinations give out the code.
TCU Codes

 

[chet1185]

The meter needle just bounced back and forth. The person that I'm buying the car from says sometimes all gears work, other times just 3rd. Could the tcu be acting up and not completely crapped out yet?

Ok, heres what i was just told.

The transmission worked fine before the owner had a garage change the flywheel because it was grinding with the starter. Now the car will only go into gear every now and then but not last long. He told me they tried to move it from where its parked. It went into reverse but they were stuck on ice. Put it in drive, nothing, back in reverse and that didnt work then either.

 

[Phantom DSM]

The meter needle just bounced back and forth. The person that I'm buying the car from says sometimes all gears work, other times just 3rd. Could the tcu be acting up and not completely crapped out yet?

Ok, heres what i was just told.

The transmission worked fine before the owner had a garage change the flywheel because it was grinding with the starter. Now the car will only go into gear every now and then but not last long. He told me they tried to move it from where its parked. It went into reverse but they were stuck on ice. Put it in drive, nothing, back in reverse and that didnt work then either.

Auto transmssions do not use flywheels, only manuals trans do. Autos use a flexplate with the torque converter. As far as needle bouncing, between what limits of voltage numbers ?
I have seen rare case where the transmission is fine but the transmission range sensor goes bad and does not allow the car to go into gear, just feels like in neutral at all times revving.
Preferably a code read would help before throwing parts at a car. Since your so far from this car, i would decide if its worth buying or be ready to negotiate for a cheaper price in case you need another trans or rebuild/ diagnosis etc.

 

[chet1185]

I had the volts set to 10 so it just bounced between 0 and all the way up. Dude swears to me that the trans was fine before flexplate install. Im thinkin someone has something mixed up or broke wires or something when they put the trans back in. If need be, i have a local trans guy that will rebuild for $300.

 

[94allwheeldsm]

[/QUOTE]The transmission worked fine before the owner had a garage change the flywheel because it was grinding with the starter. Now the car will only go into gear every now and then but not last long. He told me they tried to move it from where its parked. It went into reverse but they were stuck on ice. Put it in drive, nothing, back in reverse and that didnt work then either.[/QUOTE]

Sounds like they broke the oil pump in the Trans

 

[chet1185]

Now, i can test that by checking fluid level with car off and then with it on correct?

 

[94allwheeldsm]

Really the only way to tell is to pull the Trans. Which is what your probably gonna have to do to figure out what's going on. Where's the car located?

 

[chet1185]

Nesquehoning pa

 

[94allwheeldsm]

I was hoping it would have been farther west. I could have came and helped you diagnose it.

So be specific here.
1. Has the car moved at all since the shop did work?

2. Does reverse work at all anymore?

3. Did you hear it running? If so did you hear any weird noises?

My guess is when they put it all back together they didn't seat the converter in the pump and it broke the gears, because it will work a little while, if it's not correct, then the gears will break and the car won't move.

 

[chet1185]

He told me that the car moved in reverse at first startup. Then it quit working right away.

The car starts right up with no noises.

 

[94allwheeldsm]

Broke pump. Would almost guarantee it.

Unless all the converter bolts back out! But I doubt that.

 

[chet1185]

Whats making it move at first? If thats the problem, do you suggest complete rebuild, used trans, or just pump replacement?

Im seriously debating not getting it. Too much hassle. I own a 95 trans am and I've had the trans out and rebuilt multiple times. Not sure I wanna do it again.

 

[94allwheeldsm]

You would have to remove the Trans to replace the pump. It's not to bad. Makco Trans will have a replacement pump for around $250 to $300

 

[chet1185]

He told me that it doesnt work or stop working at a specific time. He said it just works whenever it wants to. I dont know what to do.

 

[CrackedDSM]

You answered your own question, my friend. If you don't want to deal with the hassle, pass on it. Don't force yourself to buy something, you'll only end up regretting it. Bide your time and be patient, and another, better, example will come along soon. You'll be glad you waited.

 

[94allwheeldsm]

Before you buy it I would defenatly tell him you want to see it drive.

 

[chet1185]

I'm going to try and drive it. And check the tcu againfor codes.

 

[chet1185]

Have the car home. Tested the tcu again and needle just bounces constant. Im assuming thats ok. I will take it out and open it up though. Now, the "gear selector" on top of tranny makes a loud buzzing noise when put into all gears. Is it bad?

 

[knochgoon24]

The buzzing is normal. That's the pressure control solenoid. It pules between shifts to bleed pressure off to make shifts smoother.

I would check to make sure they got the shifter adjusted correctly. Do 1st or 2nd gears work when you manually shift it into those positions?