Allpar Forums banner

1 - 14 of 14 Posts

·
Registered
Joined
·
24 Posts
Discussion Starter #1
Hi all. I have a 93 LeBaron V6 3.0L with 56k miles. Previous owner replaced a few parts including PCM and I saw a few female connectors that are in the wiring bundle close to the PCM not plugged in to anything. Are they supposed to be plugged in or are they just there to hang out with no purpose?
Here's a drop box of the pic I took of the wires: Dropbox - 20160216_203617.jpg

Also regarding the TCU. I noticed it has a bolt missing from the bottom. If that bolt was missing would it cause grounding issues and limp mode? I ask cause I have an issue with limp mode right now.


Any feedback is greatly appreciated!
 

·
Super Moderator
Joined
·
21,398 Posts
The extra connectors may be for options that the car didn't come with? The TCU (transaxle control unit) is an aluminum case and should be fastened securely to the sheetmetal. It gets its grounds externally and not through its case, but a secure installation prevents problems. They are long sheetmetal screws.
There is a wiring diagram in the service manual and you can determine the connector purpose by their wire colors (large 35 mb file).
The LeBaron coupe/convertible is an AJ-body. The sedan is the AA-body. Find the wire colors and it should answer the question of what they go to. The wiring diagrams cover all FWD models, so be sure that you are in the correct section for your model:
http://oskin.ru/pub/chrysler-dodge/...nasty_LeBaron_Shadow_FifthAvenue/93FWD_8W.PDF
 

·
Registered
Joined
·
24 Posts
Discussion Starter #3
The extra connectors may be for options that the car didn't come with? The TCU (transaxle control unit) is an aluminum case and should be fastened securely to the sheetmetal. It gets its grounds externally and not through its case, but a secure installation prevents problems. They are long sheetmetal screws.
There is a wiring diagram in the service manual and you can determine the connector purpose by their wire colors (large 35 mb file).
The LeBaron coupe/convertible is an AJ-body. The sedan is the AA-body. Find the wire colors and it should answer the question of what they go to. The wiring diagrams cover all FWD models, so be sure that you are in the correct section for your model:
http://oskin.ru/pub/chrysler-dodge/manuals/Service Manuals/1993_AX_Acclaim_Dynasty_LeBaron_Shadow_FifthAvenue/93FWD_8W.PDF
Hey thanks. That rules out the possibility of limp mode being caused by a missing bolt.
 

·
Super Moderator
Joined
·
37,232 Posts
If it were an issue with the wiring, you'd most likely ALWAYS be in second gear.
 

·
Super Moderator
Joined
·
21,398 Posts
There were many part # changes to the TCU (TCM). The finned TCM housing can be flashed with new, improved software. The obsolete, smooth-sided housing cannot be updated and is basically a throwaway module.
Definitely get the fault codes from it next and post them here. Some faults were cured by the TCM software improvements alone.
You really want the latest and greatest software that was covered in TSB# 18-24-95:
http://www.robskorner.info/faqs/tsb/18-24-95.pdf
 

·
Super Moderator
Joined
·
37,232 Posts
As ImperialCrown mentioned there were reflashes. The main thing the reflashes did was eliminate limp in mode due to low pressure situations.
I can't recall if 1993 is the last year for the smooth (not reflashable) TCM or the first year for the finned (reflashable) TCM. My A604 book is still packed away.
Of course, the TCM could have been swapped already.
But the place to start is till with getting the codes read. If it comes up that the issue is from low pressure codes, I'd recommend what I did with my 1992 New Yorker (also a low mileage car that would drop into limp mode) which was fresh ATF+4, filter and a reflashed (in the case of 1992 that meant replaced) TCM.
If you get other error codes, the repair process could be different, up to a rebuild.
 

·
Registered
Joined
·
24 Posts
Discussion Starter #7
As ImperialCrown mentioned there were reflashes. The main thing the reflashes did was eliminate limp in mode due to low pressure situations.
I can't recall if 1993 is the last year for the smooth (not reflashable) TCM or the first year for the finned (reflashable) TCM. My A604 book is still packed away.
Of course, the TCM could have been swapped already.
But the place to start is till with getting the codes read. If it comes up that the issue is from low pressure codes, I'd recommend what I did with my 1992 New Yorker (also a low mileage car that would drop into limp mode) which was fresh ATF+4, filter and a reflashed (in the case of 1992 that meant replaced) TCM.
If you get other error codes, the repair process could be different, up to a rebuild.
It does have the finned one. I feel like it's been replaced possibly cause the bottom bolt to body is missing. I thought the upgrade at the dealership might help, so I thought about it. Getting codes scanned first was my primary plan.
 

·
Super Moderator
Joined
·
37,232 Posts
It does have the finned one. I feel like it's been replaced possibly cause the bottom bolt to body is missing. I thought the upgrade at the dealership might help, so I thought about it. Getting codes scanned first was my primary plan.
Look for a decal on the TCM with a part number - it may already have the latest software.
 

·
Registered
Joined
·
24 Posts
Discussion Starter #9
Look for a decal on the TCM with a part number - it may already have the latest software.
I'm guessing it'll be noticeable and not hard to see?

Also it seems those wire connectors are for the abs pump relay and the other is for security....wait does that mean I don't have ABS?
 

·
Super Moderator
Joined
·
37,232 Posts
Most LeBarons did not have ABS.
The sticker may be on the front or even sometimes the bottom of the TCM (sometimes you can't see it until you remove it). Or it may have fallen off.
 

·
Registered
Joined
·
24 Posts
Discussion Starter #11
Most LeBarons did not have ABS.
The sticker may be on the front or even sometimes the bottom of the TCM (sometimes you can't see it until you remove it). Or it may have fallen off.
Okay thanks. I'll give it a look see when I get home. Will get back on that later today.
 

·
Registered
Joined
·
24 Posts
Discussion Starter #12
Okay so I looked and didn't see a sticker. Also I called dealers around here and only one had some old thing that could hook up with older cars but it needed repairs. Is there another way to get this thing's software for the TCU updated?
 

·
Super Moderator
Joined
·
37,232 Posts
Buy a used TCM from eBay or a salvage yard with the new software already installed on it. The flash part is: 4686606.
However, 1993 is the first year (I believe) that had to have the pinion factor (to properly run the speedometer) so if you buy a used one the speedometer may be off unless the donor car had the same size tires.

The good news is there are aftermarket scanners (still expensive, but more common than the dealer ones) that can set the pinion factor. But only the dealer ones can install the software.

I still think you are getting ahead of yourself worry about computer software without knowing the error codes. Why spend the money for a TCM if you don't know if the transmission is any good? I wouldn't and I've bought several of these cars with "dead" transmissions that really weren't bad - but I ended up with one that did need a rebuild before I got my own scanner to check them. The bargain car wasn't such a bargain with a $1200 transmission needed.
 
  • Like
Reactions: ImperialCrown

·
Registered
Joined
·
24 Posts
Discussion Starter #14
Buy a used TCM from eBay or a salvage yard with the new software already installed on it. The flash part is: 4686606.
However, 1993 is the first year (I believe) that had to have the pinion factor (to properly run the speedometer) so if you buy a used one the speedometer may be off unless the donor car had the same size tires.

The good news is there are aftermarket scanners (still expensive, but more common than the dealer ones) that can set the pinion factor. But only the dealer ones can install the software.

I still think you are getting ahead of yourself worry about computer software without knowing the error codes. Why spend the money for a TCM if you don't know if the transmission is any good? I wouldn't and I've bought several of these cars with "dead" transmissions that really weren't bad - but I ended up with one that did need a rebuild before I got my own scanner to check them. The bargain car wasn't such a bargain with a $1200 transmission needed.
Sorry I do get ahead of myself and forget a few steps. I'll just take it in to AAMCO, the only shop around here that'll scan for the error codes. I guess after that is when I take the next step then.
 
1 - 14 of 14 Posts
Top