Transmission Control Unit, how to change it out?

Sure, it looks like the TCM/PCM is by the throttle pedal here is the location in the images below. Please let us know if you need anything else to get the problem fixed. I would check the U joint is the driveshaft, transmission and engine mounts as well.

Can you recommend a step-by-step instruction video or written explanation telling how to switch out the old with the "new"(used)? Do I need to remove the battery cable first to save the codes? Also, I can't find a mechanic near me (Lower Queen Anne). Can you refer me to one? Lastly, is it safe to drive it to the shop?
Thankfully, Miriam

Yep, sorry about that. here is a guide to help you change the unit out, also you can get a preprogrammed unit by searching Google or Ebay. I am sorry we don't know of any shops in your area that can help. You can use google maps to find reviews and the locations of the shops and then call them.

Please go over this guide and report back.

Thank you so much for the step-by-step instructions to replace the TCM. As soon as the rain lets up, I give it a try.
God bless you! Miriam

Hi, again. As you know, I am not a mechanic, however, I am determined to fix what I can fix. To wit, I followed your instructions and discovered that 1) There is an insulated cable on top of the unit. Additionally, the bolt that needs to be removed from the right side of the bracket is unreachable. I assume that someone else needs to be removed to get at it. You can only see it on a cell phone. There is a yellow collapsible tube running to the back seat. Probably not necessary to remove, right?
I am so close, unhooked the battery cable, wore the wrist strap, bought the silicone grease, got the wiring harnesses off and now what? Do I need to remove something else in order to get at the bolt securing the TCM?? I really appreciate your help!!
70 yr. old grandma Miriam. P.S. It sucks to be old and poor.

I am sorry, please upload images of what you are seeing so I can help walk you through it.

Here are photos of the transmission unit and bracket with the bolt on the right bracket. It looks like the unit has to slide up vertically but there is an insulated cable above the unit and it is secured tight in the bracket.

Yep, it looks like it is close good job so far, it looks like there are 10mm bolts holding the bracket down, but can you slide the unit toward the gas pedal, there might be hold down clips? Let me know.

Hi again. Got the two bolts on the right side but can only lift the unit off the bracket on the right side. Can't see any bolts on the left side. The black insulated hose is tight on that side. Also, tried to pull it straight out towards the accelerator pedal but it has to be lifted off the right back remaining bolt. Only the nut came off. Could you send me a pic of any clips that may be holding it in on the left side? I really appreciate your assistance.

Hi Miriam,

The images above all they show, can you access the TCM from the other side of the dash to see what's going on? Please upload images of what you see so I can help.

Sorry, don't know if these will help. The unit seems to be dislodged, but couldn't lift the left side up enough to move it out, towards the accelerator pedal. I felt around the left side, and it felt like there is a bolt in the front. Could that be holding the unit to the left. bracket?

Yep, that looks like the PCM needs to come out first which is the box on the top of the TCM. Can you see how to remove it? There should be a clip or hold down bolt.

I finally got the nut off the front left bracket of the TCU. Couldn't get it out of the driver's side so removed the panel off the passenger side. Then I pushed the unit towards the pass. side and was able to jiggle it out from that side. Hurrah! Now, how do I get it off the brackets?

Good job! Please upload an image of what you are talking about

Sent three pics. I can't slide them out, even using a large screwdriver. Do I need to try to find brackets for the replacement unit?

Hi,

I noticed it has been a couple of days since we made contact with you. Have you been able to make any progress?

As far as the brackets, take a thin straight screwdriver and slide it down into where I have an arrow pointing to depress the locking tab I circled. That should release the bracket.

Let me know.

Take care,

Joe

See pic below.

Yes, I used a thinner screwdriver, and the bracket flew across the room. Installed the "newer" TCU from the passenger side. Couldn't get the front bolt to line up, so I wiggled the unit and it was immoveable. Forgot to use the silicon on the plugs, but they went in easily. The ck. engine light wasn't on and no clunking sounds when I took it for a test drive! Should I disconnect the three plugs and put the silicon on or not? Tomorrow, I'll test it again with the Autel diagnostic tester.
Thanks for all your help; I feel ok driving again.
Miriam

Hi,

That is good news. I'm glad to hear it is running well again. As far as using dielectric grease on the spark plug boots is concerned, it is a good idea. It keeps moisture out and prevents the boot from being damaged when it is removed.

Regardless, thank you for the update. If anything changes, let us know. Also, feel free to come back anytime in the future.

Take care,

Joe

I asked if I needed to grease the three wiring harnesses that I plugged into the TCU, not the the spark plug boots. Wanted to know if it's necessary before putting the trim back on.

And, do I spread a small amount of the dielectric grease on the male plugs?

Hi,

It would be a good idea to do it. As far as the spark plugs are concerned, I like to put it inside the boot before installing them on the spark plugs.

Let me know if that helps.

Take care,

joe

I'm not under the hood. Just asking if I need to grease the TCU three wiring harness plugs that plug into the TCU itself on the driver's side. I wish Ken would have seen this through.

Hi,

Sorry, I read the last few posts wrong. I thought you were asking for both.

Is it required, no. Is it recommended, yes. Anything that will help ensure a good dry connection (inside or outside the vehicle) is a good idea.

Let me know if that helps.

Joe

I put the panel back on, started the car, and now the check engine light is back on. Previously, after plugging the unit back in, the light didn't come on after turning it on. Is it safe to drive?

Hi,

Have you rechecked the connector to make sure it is fully seated? As far as safety is concerned, that is a hard question to answer without knowing what turned the light back on.

Is it possible for you to scan the computer again?

Let me know.

Joe

Yes, I plan to tomorrow. Also, I didn't ck the connectors since they clicked in, but will ck them tomorrow. I was planning to start moving Sunday but want to do it safely.
Thanks for promptly responding. I still want to know how much dielectric grease to put on the connectors, sincee I'll be unplugging them and plugging them back in.

Hi,

As far as how much dielectric grease to use is concerned, just enough to cover the connector contacts.

Let me know what you find, and I hope you have a safe moving day.

Take care,

Joe

Learned that dielectric grease is not used on TCM connectors. I used the scanner again and it reads that there's a problem with, you guessed, the TCM.Took off the panel, battery cables and called it a night. Tomorrow I'll pull the "plugs" and reinsert them.

Retested the TCU and it still reads problem. Read more online and rechecked the transmission fluid, which was right on, full and red. Do I need to reset the TCU? It clunked just pulling it forward.

Hi Mariam, are there specific codes you are getting related to the TCM? If so, let me know what they are.

Also, what clunked when you pulled forward? Do you mean the transmission clinked when placed in drive or did something make noise when you started moving forward?

Joe

Just test drove it and it only clunks going into reverse. But now, the speedometer doesn't work.

Hi,

You aren't having too much luck with this. As far as the speedometer, did you do anything with the transmission output speed sensor? Check to make sure it is connected and there is no damage to the wiring. I attached a pic showing it below.

Let me know.

Joe