1Louder

Thought I'd document my recent experience here - if nothing more to provide a place for others to comment if they have a similar issue.

For context, I have a V6 SH-AWD Tech that was purchased in Feb 15, built in Jan 15, and I have about 7K miles on it so far.

Yesterday morning as I was backing out of my driveway the car slammed to a halt. I wasn't going very fast, but slammed is the right word to describe how it stopped. It was immediate and with a loud "bang", almost like I ran into something. Immediately following, I got transmission warning light, emissions warning light, and emergency brake warning light. The engine transmission and e-brake controls were unresponsive at that point (however the car was in Park, but I could not take it out of Park). It felt like the e-brake was engaged but I'm not 100% sure. The engine would start and stop OK. After maybe 3 restarts, the transmission came back enough for me to select a gear and move the car short distances. However this process repeated twice more getting the car onto the tow truck.

The dealership confirmed today that the Transmission Control Module had failed. So, I'm getting a new one and will get the car back in a few days (they have to ship the new part).

Part of the reason I'm writing this down is the fact that I find it somewhat distressing that a failure in this module basically slammed the car into Park while it was moving. I'm going to talk with the tech and see what other information I can get - will add to this when I learn more and get some paperwork. My main question is if the TCM fails at say 50 mph what happens? I know parts fail, and sometimes bad things happen when parts fail. Maybe this is the 1 in 1,000,000 chance this part fails. It may be a short thread then. But if not, just leaving a trail.

Back with more soon.

Rocket_man

How did they rule out damage to the transmission itself with whatever caused it to 'slam' to a halt? Why not replace the entire transmission? Are they at least going to give you a longer warranty for the transmission if they are not going to replace it?

ltommylel

Thats a scary thought to have your transmission slam you into park while you're going at a high speed... Hope all goes well.

Hoosier_TLX

This is a very scary thought. If at a low speed such as what happened to you it could still be very dangerous given the situation, but at high speed it could be devastating. I would prefer if the tranny would just go into neutral and let the car coast to safety.

Let's hope this is a unique problem and something that doesn't start to rear it's ugly head (especially if it causes any injuries or worse).

Keep us updated on what the Acura techs let you know.

1Louder

I'm going to keep a close eye on the transmission itself for issues. I'm reserving judgement until after I pick up the car and drive it. To be honest, this whole thing has changed my plan in that I will return the car when the lease is up. So I'm not going to be driving it past the warranty.

The visit with the tech wasn't too revealing. They applied a recall and two service bulletins (038 and 040) and the problem was still there. They swapped the controller out with one from another car on the lot and the problems all cleared. That was the extent of their diagnosis. However, that's about all a dealership can do. It's a sealed black box and they can't open it. They did say it will go back to Acura for analysis. But I doubt I'll be able to learn anything.

I also didn't get any good answers about safeguards for this happening at driving speeds, other than noting that the controller unit does get speed data from the main computer. No idea what it does with that speed data, but common sense would dictate that the controller should have some very robust safeguards. In mechanical transmissions, you are locked out from putting the car in park if it's moving. One would think there is an electronic equivalent. And I was basically just rolling backwards very slowly - maybe I was just right on the border.

I probably will not get the car back until Tuesday. I'll see if the paperwork says anything interesting.

csmeance

My 760 did something similar when traveling at 20MPH. I got a god awful grinding noise 5 seconds before it happened. The E-brake activated and if felt like the car's transmission slammed into park. The car stopped after a 10-15 feet but it felt worse than getting rear-ended. Car was towed to BMW and I got a new trans, drive-shaft, gubio joint and rear differential 2K miles later.

The 760 used the Electronic shifter similar to what the TL has, with a ZF 6-spd transmission. I went through 2 of them so far.

I guess it's programmed to apply the E-brake to slow the car but there's some issue of internal damage happening. I'd get a fluid sample of the trans fluid and have it checked for metallic particles and insolubles that might have broken off the trans into the fluid during this event.

Be sure you talk to the tech that worked on the car before you leave, usually dealerships won't put anything meaningful on the paperwork they hand to you. The paperwork they keep has all the info that the tech provided to the dealership and Acura during the whole process. Very rarely will the service dept allow you to read/see those.

1Louder

^ I will have them investigate the transmission. Although I'm 99.99% resolved to simply turn this car in at the end of the lease. I want no part of it out of warranty. It's a shame too - this is my 4th Acura (plus 2 Hondas) and without exception they've all been bullet-proof. Out of all six cars this is the 2nd warranty fix between them all. And two of them were 06's that we drove for 9 years.

So I got an update - after the dealer accidentally didn't select overnight shipping for my part it finally arrived today. They put it in the car and now the dash won't stop flashing. So now it's back to Acura engineering.

You know the 4 cyl I'm driving as a loaner is not a bad car. If it had the tech package it would be downright acceptable. The 8-speed transmission is smooth, and the AWS is a real kick. Maybe this time more wasn't better.

csmeance

I'm sorry you had this experience, but all of it stems from having the transmission outsourced to ZF. ZF has been having a lot of headaches with the 9 speed especially in Chrysler cars. I wish that acura would pull their heads out of their butts and offer older trans choices like the 6spd auto or manual before putting a half-assed transmission in the car.

1Louder

It's very uncharacteristic of Honda IMO. I just borrowed my parents 2013 Odyssey minivan over the weekend for a long trip and the transmission is so smooth you'd swear you were driving a CVT. The fact that they can get this right, and botched it so badly on what is supposed to be their A4/lower spectrum 3-series competitor is just beyond me.

Still no word on when I'll get my car back.

1Louder

I finally got my car back yesterday. There isn't anything new to report on the TCM issue. However the part they ordered seemed to have an issue they could not resolve, so in the end they took one out of a car they had on the lot and it installed fine. So far, car runs like it did before. Nothing more to do than monitor the situation now - thread will be around if anyone else has this issue. But I hope not - this would be bad if it showed up in more cars.

Rocket_man

Hope the car has no hidden damage from this. Did you ask about an extended warranty on the transmission?

1Louder

I didn't ask. They actually bent over backwards trying to fix it, and I was basically coasting backward when it happened. I'm not terribly worried about damage. If I were going faster, or if this happens again at any speed, absolutely. Also, it's a lease and I'll be turning it in when it's up, right around when the warranty expires. This was enough for me to not want the car out of warranty. I didn't get a price, but the service guy was even shocked at how expensive the TCM was so I can only imagine. I'll just enjoy the car for three years and see what my options are at that time.

Bobzmcishl

I noticed that when I took my 16 RDX Advanced into dealership for transmission issue, & the diagnosis and repair information was very sketchy and when I started asking questions, the service rep started getting very defensive and refused to give me a straight answer on the transmission issue. Sure enough three weeks later the same problem reoccurred and this was after an AT transmission flush and a software update. My RDX has only 23,000 miles on it after six years, so needless to say, I am very disappointed.