92 Laser RS Turbo Auto Trans No Overdrive

[Bob White]

Help !!!!!
92 Laser RS Auto Trans Turbo
Seems like trans is only getting third gear, slow to accel., 3100 rpm at 50 mph, OD on/off switch turns OD on/off light on and off but no change in rpm, trans fluid clean and full, also even when manually selecting low gear nothing seems to change, same exact performance !, all other trans op's are fine.(no slipping, reverse fine, etc..)
Any Ideas ??
Thanks in advance,
Bob

[CraigB]

You probally have a worn out end clutch.

[Bob White]

Hi Craig,
Thanks for the input, but i think i'm looking at more of a control problem rather than a physical problem of the trans, been in a similar situation with a 93 lebaron, shop guess was trans change, told them to r&r the speed / distance sensor and fixed the problem, i think if i had any sign of slippage or any other odd bit i would agree with you but in this case i think it's much more simple, but i really do thank you for your response so fast, i have seen a few other similar posts like this on "ALLPAR.COM" but no replys there yet,
thanks again craig,
have a great one,
talk to you soon,
Bob

[CraigB]

Sorry I did not get the part about feels like only 3rd gear.

There are many reasons your car could be stuck in 3rd gear. I would take it to a shop that can read the codes from your TCM.

Reasons that could cause the TCM to go into limp mode (3rd gear)

1. Power loss to shift solenoids or TCM
2. no or poor signal from pulse generators.
3. clutch packs slip

There are more but these are the big ones.

[Bob White]

Hi again Craig,
a bit more info i can supply...
1) checked tranny codes - using voltmeter at data port pins 1 and 12, readback was steady low / high voltage - according to manual this is a normal condition and no faults detected ?? i have reset all the plugs i could find, no help...
is the fact that by even selecting low gear with the shift selector and still being in 2nd or 3rd a clue ? or once the trans goes to limp mode is that all you will get - Period! i wish i could find a good elec. schematic for this thing, it would make troubleshooting a lot easier. any other ideas or clues / hunch's,
thanks in advance,
Bob
p.s.
only reason i hesitate to take to shop is i know their fix will be tranny change whether true or not, wish i could find honest shop, had bad exp with a local one here in plymouth, 93 lebaron "bad trans"($2,000.00), i fixed for $18.00 speed sensor anyway, thanks for any input,
talk to you soon
Bob

[Rdy2race]

well the tranny goes in to the limp mode and the car will only go in 3rd ( with both solenoids open, no power to them is 3rd gear ) gear. the reason is a list of many. The TPS, the solenoids , the TCU, the harness and so on all could be a problem. Did the trany act up before it did this? the history of the car will help a great deal to tell what it is.


I do understand what your talking about when the fear of bringing it to a shop and getting hit for 2K. I don't know where your located but the Mitsu Graveyard does rebuilt tranys and is a great place to know for problems like this.

Best of luck to you, contact the graveyard

BM-

[Bob White]

Hi Bill,
No everything has been normal right along, nothing stange has ever occured (as far as i know anyways, wife's car, she could drive around with only 3 cyl's firing and may not notice !!!!, really not that bad but you know what i mean)
so am i to understand that in fact if the trans has gone into limp mode that manually selecting low will have no effect ?? if so than i feel stronger than before about a control issue versus a physical problem.
very frustrating though !,
would you happen to know the plug and pins for the solenoids that you wrote about, perhaps i could read power there or read through the coils of the solenoids,

any ideas would be appreciated a ton.

car has approx 80,000 miles, always taken well maintained, no engine or trans problems (other than a stalling prob a couple of yaers ago, throttle body cleaning fixed that)
thanks for the help guys

talk to you soon,
Bob

[Bob White]

Hi You Guys,
A touch more info,
1)reading from the tcm plug thru the solenoids i'm getting 29 ohms ea. (wiring and solenoids must be good)

2)reading from the tcm plug to the pulse generator to ground 20 ohms. (wiring and pulse gen must be good)

3)engine running, in "drive" both solenoids getting 6 volts.

4)engine running, low gear manually selected both solenoids getting 6 volts.

still can't buy an internal trans failure but not sure i want to invest $$$ for a tcm until i'm sure.

hope this info starts to narrow it down,

thanks everyone,
Bob

[don]

i know why your transmission is not shifting out of 3rd gear.
email me at dhg07777@aol.com
ill be glad to help

[Bob White]

Me Again,
latest info,
i read the tcm data port pins with a volt meter, no codes, (pulses on the VOM),(which as one manual states, is either a good sign or an indication of a tcm failure, good system eh?) anyway, brought the car to american transmission, they hav'nt found any codes either but are going to look over connectors and wiring again on monday, maybe i missed something, the tech there also feels the problem is not internal to the trans, but the controlling system, an interesting thing though is that on ALLPAR's site another person is having an identical problem with their 91 laser, i know if i had a detailed electrical schematic this would be a peice of cake to figure out, is there a good source for true service and electrical manuals other than the dealers ?
thanks again and i'll keep everyone posted as we go and whatever the final fix is,
Bob

[Blackboost]

Originally posted by don
i know why your transmission is not shifting out of 3rd gear.
email me at dhg07777@aol.com
ill be glad to help

Why don't you share the info with all the other members??;)


As for the problem at hand...
Try having the "shift solenoids" (that are on the tranny valve body) checked out. When this go out they like to leave the tranny stuck on 2nd or 3rd gear. They are a bit expensive from the dealer...:(

Also take the TCU out and check for leaky caps. They suffer from the same plague as the 1G ECUs...

[don]

you tcu is probably bad .
i have had two cars with automatic transmissions.
(both stuck in third gear). both times it was the tcu.
there are alot of people parting out car on dsmtrader.
you could easily find one there.

don

[Bob White]

Hi Again Everyone,
First off, wanted to say thanks for all the advice and help, this is one heck of a site !!,
And now for the latest,
I went ahead and paid my $25.00 for a sub to alldata.com for the laser, (well worth the money), i was able to get all the wiring prints for the tranny and rang the system out, everything checked good(solenoids, speed sensors, etc..., made a buzz box to read the diag connector (another great idea, much easier than trying to read a volt meter sweep),i think i mentioned before that there was zero volts at the diag conn pin for the tcm, however with a buzz box i could actually here that an erratic, weak, and intermittant signal was in fact there (the vom wouldn't show it, digital or analog) so the long and short is that i found a tcm in Fla. and it's on the way, should be here tues, i'll let everyone know the results.
Again, thanks for all the help, i now have the proper resistances and test procedures for all the sensors and such for the 92 2.0 turbo 4 spd auto trans so i will watch the forum and try to repay all the help i have recieved,
thanks again, and i'll write back just to confirm the fix
Bob White

[Bob White]

Well as i promised here are the results:
first thanks again, twas the TCM, first one i got gave a code 47 (open clutch damper solenoid circuit), then code 86 then code 54 then back to limp mode, however the 2.0 turbo does not use this circuit at all, so while the tcm was in fact reporting a correct code (because that system does not exist in this car) it was not the correct tcm for the turbo 2.0, returned that tcm, got a new one and all is well.
interseting thing is that they were the same part number (at least the outer can had the same p/n)
thanks again for the help, and you guys had it pinned from rhe start, i just wanted to be positive before spending the $$$.
Bob White

[Blackboost]

Glad to hear that its working nicely once again...;)

Thanks for the feedback...:)