94 thunderbird ??

Engine?

Does your Cruise Control work?

Take it to Autozone, get codes read out, if it's a 4.6L

As Backyard said, the first thing you need is to get the ECM scanned for any fault codes. Any of fault code related to vehicle speed or load may cause this. The nuetral switch on the trans can cause this erratic operation w/o setting a code in a lot of vehicles. But, don,t touch anything until you get the ECM scanned and have some idea what you are working with.

Lugnut

I belong to 94 TB LX V8. After considerable search, the connection for my ECM was found under the dash on shotgun side. Might wanna check there first, maybe save a little time.

Pudd>I have a 94 thunderbird that shifts erratically. if I am in town and only

Those had a flaky gearshift switch. The shifter controls a switch, not a linkage to the trans. The switch gets flaky, and shifting gets erratic. Had this in my 94 Cougar. Fix is fast, get it from the bottom. I got lazy and had the dealer do it.

Local transmission shop insisted it was going to take a new transmission. I feared the dealer would be worse. But it was done by three hours after I dropped it off.

Check the switch, may be a quick one to fix.

-GeorgeC

Me: '94 Tbird LX V8

The "switch" is the MLPS. I replaced the one on my

4r70w 18 months ago and it fixed it, but I had different symptoms.

The "computer" on the '94 has had problems. As near as I can tell, for years, if you asked for a '94 replacement, they'd hand you a '95 computer.

Others (lugnut?) may have add'l relevant info.

Cheers, Puddin'

I just bought a 94 LX with the 3.8l V6, and have noticed some erratic shifts once in a while.

What does "MLPS" stand for?

Is this something a parts store would have, or is it a dealer part?

How difficult is it to replace this switch?

Thanks for the advice guys!

Gerri

Manual Lever Position Sensor. It's on the driver's side of a 4R70W transmission, and takes maybe 5 minutes to replace once the car is "up" or over a pit. The weather seals on these things weren't very good up thru mid-'95 and have caused transmission problems.

Correct. Did they mate the 4r70w to the 3.8?

No, its not necessarily that easy. There's an alignment issue with the lever on the console ...

Actually, they were horrible.

Lots of 'em.

I found a replacement at Auto Zone maybe 18 months ago. Much easier to install (on my 4r70w, '94 TB LX V8) than what they had at the dealer. Under $30.

Suggest to Gerri to describe erratic shifts in as much detail as possible. Also some indication (numbers on the door plate ?) of which tranny on the car and mileage.

Cheers, Puddin'

Yes, you have to be aware of the neutral alignment issue, but there are a number of places on the 'Net that have detailed instructions for this. Here's one:

I found a replacement at Auto Zone maybe 18 months ago. Much easier to install (on my 4r70w, '94 TB LX V8) than what they had at the dealer. Under $30.

Suggest to Gerri to describe erratic shifts in as much detail as possible. Also some indication (numbers on the door plate ?) of which tranny on the car and mileage.

Cheers, Puddin'

Hi There!

Went out this morning and looked for numbers. This is what I found on the sticker on the door.

Body - LX2 VR - MCDG - R INT TRM - X6 Tape - R - H S - AX - 5 TR - LCCMM

The 'erratic shifting' happened on the second test drive. I took the car down a curvy road with many small hills. More than once, when coasting down a small hill, it seemed as tho the car downshifted into a lower gear. This only lasted a few seconds before going back to the top gear. I watched the tach and the needle would jump from about

13-1500 up to 22-2400 rpm. And NO, I wasn't over-revving the engine. Since I bought it, I think this has happened only one time, again when I let off the gas while going downhill on the highway. And again, it went right back to the higher gear.

I know the car hadn't been driven much in the 2-3 months before I bought it. I've had it now for about three weeks and it is almost a daily driver. Could the problem be from being parked for a while and now that it is back in use, the problem is correcting itself? Or, should I go ahead and replace this 'switch'?

The mileage on the car is just shy of 84,000.

Thanks for the advice guys!

Gerri

This is consistent with the MLPS problem that I had.

I seriously doubt it.

Safety first. You've got some idea how it malfunctions. Not a big deal in light traffic. If it happens on a hiway interchange (it did to me), it could cause an accident. So be careful.

It was an erratic problem for me. 4-5 years ago it might happen only 3-4 times a year. Progressively got worse until I replaced MLPS.

Here's what I did: let off gas, shift to neutral, then shift back to drive. This always got me under power again.

My door code sez: TR L33FF

So I'm still not certain which tranny you have (I forgot individual meanings of these codes). You might wanna start a new thread like "ID tranny and MLPS: 94 LX 3.8l V6 " to nail it down. I'm not sure what-all trannies had the defective MLPS.

The important thing is to fully identify and track the problem. If you want to replace the MLPS, I'll help with additional info.

Puddin'

Thanks. I've never seen any breakdown of the codes.

My '94 TB LX V8, I guarantee.

As I understand it, the other 94 TB tranny is AODE, which has (old style) hydraulic downshift.

Safe to assume that all 94 TB 3.8's were mated to AODE?

Safe to assume that all AODE's had same MLPS as 4r70w?

I notice the TR codes don't have anything for, say, supercharged V6 and manual tranny ...

Respectfully inquiring: So, if Gerri's is "TR - LCCMM" and mine is "TR L33FF", how do we make sense of your code table (for trannies)?

Thanks, Puddin'

How To Tell How Your Car is Equipped

There is a small metal tag that is mounted inside of the front-passenger door. This tag, known as a Vehicle Certification Label, contains a lot of information about how your car is built and equipped. Diagram 1 below shows what a typical VCL for a 93-97 PI might look like.

There are several code fields on a VCL. It makes it easier to remember that there are codes that are above and below the horizontal dividing line. The two character code on the left side of the tag, and above the dividing line, designates the body paint color code. The codes on the right side, and above the dividing line, are District codes that designate where the car was built, and special order codes.

The codes below the dividing line, from left to right, are as follows:

BODY = Body Type MLDG = Moulding Color/Type INT TRIM = Interior Trim (Seat Type/Color) Tape = Tape Trim Type R = Radio Type S = Sun Roof or Roof Sliding Panels Type (N/A on a PI) AX = Axle Type (Ratio and locked/unlocked) TR = Transmission type and suspension spring type

The following are the known (at least by me) codes for each of these fields:

Body Color:

DZ = Light Saddle FG = Medium Berry Metallic FL = Toreador Red HB = Ivory LD = Medium Wedgewood Blue SL = Light Willow Metallic SH = Medium Willow Metallic TS = Silver Frost TR = Medium Graphite UA = Ebony Black WT = Performance While

Body Code:

FC = Police Interceptor (P71) BA4 = P72 Fleet Car or P73 Basic CV LX4 = LX Model CV

Moulding: Should always be CC for color coded to exterior paint color.

Interior Trim (First Part = Seat Type):

K or M= Cloth K-Split Bench C = Leather K-Split Bench E = Vinyl K-Split Bench H = Cloth Bucket I = Cloth/Vinyl Bucket

Interior Trim (Second Part = Interior Color):

C = Currant N = Cordovan G = Willow L = Willow and Ivory P = Portofino S = Saddle X = Oxford White and Light Graphite 2 = Light Graphite M = Portofino and Light Graphite

Tape Trim Type: N/A

Radio Type:

6 = AM/FM/MPX, Electronic Premium Cassette F = AM/FM Stereo, Electronic H = AM/FM Stereo/Cassette, Electronic L = Luxury Radio AM/FM Stereo/Cassette 2 = Radio Delete

Sun Roof/Sliding Panel Codes (N/A on a PI):

B = Sliding C = Removeable

Axle Ratio:

8 = 2.73:1 Z = 3.08:1 5 = 3.27:1 (Unlocked) E = 3.27:1 (Locked)

Transmission Type:

U = Automatic Overdrive, 4R70W (Standard on all CVs) X = Automatic Overdrive 4-Speed, AX4N

Suspension Spring Type (This is a four character code. The letters represent, in order, left-front, right-front, left-rear, and right-rear):

Front Spring Codes (Part Number and Catch Word):

2 = F4AC-AA/AFD 3 = F4AC-BA/BOS 4 = F4AC-CA/CKV 5 = F4AC-DA/DHL 6 = F4AC-EA/ETR 7 = F4AC-FA/FPK N = F4AC-ANA/NUL

Rear Spr>

FYI, the AODE and 4R70W are essentially the same trans with the exception that the 4R70W used the same gearset as the trucks had used for a higher ration 1 and 2. Both are electronic units. There are of course other more subtle differences. The AOD (no "E") is the hydraulic unit.

Lugnut

It was the tranny guy at the local Ford dealer told me that AODE had hydraulic downshift, elec. upshift. Both are electronic for 4r70w. Differing MLPS unit? Damned if I know: never hadda AODE.

I never tell folks that such stuff (i.e. MLPS) is identical unless I have personal knowledge. I ain't a pro.

Other Q's above remain unanswered ...

Puddin'

I believe the MLPS is the same on the AODE/4R70W units as the big diff is the gear set. There was a change in the electronic specs beginning in 1995 year IIRC. Erratic shifts and nuetrals were a hallmark of bad MLPS units in the whole line of Fords thru 1996 or so. Hell, I'm not sure they have a surefire handle on it now.

Lugnut

This is consistent with what I heard from the Ford dealer ...

You mean upper line, i.e. TB, CV, LTC? They didn't put the "Headache Switch" on Essy-Cort trannies, did they? :-)

"Don't Get Me Stahted (It Only Hurts When I Laugh)!"

Cheers, Puddin'