taylorbuc1

Just a few minutes ago the D5 gear light on my MDX light started blinking after a hard bump and gear shift. When I arrived home I shut the engine off and restarted the engine and the light did not blink. What should I do now? What could the problem be? Is it expensive?

jvette

When the D5 light is flashing while driving, an error in the transmission system has been detected and you would need to retrieve the trouble code to proceed with diagnosis and rectification

Majofo

Get the DTC code. Also, can you give more details on the "hard bump and gear shift" comment. Model year & miles of your MDX would be helpful as well.

McDuc

I have the dreaded blinking D5 light. I see that this can be many things, so I have been trying to pull the code. 2004 MDX, 99,000 mi, runs and shifts normally, no bad noises yet. No check engine light, trans fluid clean & smells fine. Flushed and replaced (Oil Can Henry's) 30K mi ago.

I heard Autozone can pull codes for free but no luck there. One store had a simple device that, they said, can only read check engine light codes, not trans codes. So got no results there.

I noticed the light does not start blinking when the car is started, it takes between 5 mi (when cold) to .2 mi (warm) to start to blink.

So I went to another A-zone store, with a different code reader, and had them plug in while the car was running and D5 light blinking. Still no code.

Then its off to the local independent shop - staffed by former Acura guys. One said D5 light = new trans, so why bother pulling codes(!!!). Then he called his tranny guy who said it could be lots of other stuff. I told them light would not blink on start up but they tried to pull codes anyway (light not blinking) and could not get any. So they said to wait for it to get worse. At least they did not charge me anything.

Is the dealer the next step? That is probably $100 + to pull code. I can work on it myself, but finding this code is getting to be a real pain.

Anyone have this problem pulling a transmission code?

csmeance

I believe only the Honda Diagnostic tool can pull the transmission code, so it may be time for a trip to a honda specialist with HDS (honda diagnostic system)

Majofo

A decent OBDII reader should be able to read the code. My guess is if it's operating fine, it's probably a minor electrical issue / sensor. Don't take it back to the shop you visited. They're assholes. Pull the code and get back to us.

McDuc

The local shop claimed to have the right stuff, but looks like I will need to call around and find some one with HDS.

Thanks!

McDuc

From all I have researched a regular OBDII reader should get it. I bought one at Sears (seems a good thing to have anyway) for $70.00. It is an Actron "Pocket Scan Plus" and seems to work fine.

But still reads "no codes"! And the D5 light is blinking merrily away. Tried reading it all ways possible. Car seems to run OK.

I can keep the reader in the car and check occasionally, but this is starting to bug me. I can't find any threads about my inability to pull a DTC with a blinking D5 light.

Think I should wait for a check engine light?

csmeance

just as I said before, the regular tools you are using will only get OBDII errors that relate to a check engine light! If the D5 light is blinking, you will need the HDS system to pull the code. Try calling up your dealer and ask if they get the DTC code.

McDuc

OK, I've got am appointment with an Acura shop tomorrow here in Portland, OR. I confirmed they have the factory authorized code scanner. I'll let you know what they find.

Thanks!

Majofo

Get back to us before agreeing to any work.

black label

Listen to this man he speaketh the truth. The Honda Diag tool is far from a "code puller" or "scan tool". It is more like the Apple Tablet and costs roughly 4 times as much to purchase.

McDuc

I went to a reputable Acura shop and they succeeded in finding a code:

"pulled codes from transmission control module: fault 27-04 4th pressure SW circuit high"

question # 1: Could this be the external 4th gear pressure switch which can be replaced inexpensively?

question # 2: if it is, and I replace it, will that clear the code and the blinking light, thus confirming the repair? Or do I need to get someone to clear the code with the Acura diagnostic computer?

Thanks for your help.

Tom

Majofo

yep. change them yourself.

McDuc

Heading out to get parts. Might as well do them both, I think. I'll post results today.

McDuc

Bought both 3rd & 4th gear switches, washers, and installed them per MOJOFO's DIY. See:

https://acurazine.com/forums/1-2g-mdx-2001-2013-166/03-06-mdx-3rd-4th-gear-transmission-switches-sensors-diy-747378/

Parts were $100.00 at my local dealer, Tomkin Acura in Portland. Did not want to wait for a mail order. Installation was a breeze, save for the crappy little plastic clips. I only trashed one of them, but be careful & buy a few as recommended.

So far no blinking light. I drove the crap out it for 15 miles, which would surely have had it blinking before. So I think the fix was a success!

Conclusions from this adventure.

Condition: Blinking D5 light after driving several miles. Resets to normal at key off, then takes a few miles to start blinking again. No Check Engine Light or other warning lights.

Reading code: Code could not be read by two Autozone stores, one foreign car shop, and by a OBII reader from Sears. Finally found a better shop but they had to get into the transmission controller to get the code. It took them awhile and cost me $45.00. I could not find this code number ("27-04") anywhere on the web but it called out a 4th gear pressure SW fault.

Replaced the switches and so far no blinking light. Seems to shift better too, but not a remarkable difference, just seems tighter and more solid.

Thanks to MOJOFO and the others on this site I think I have saved the $5,000.00 the first shop would have gladly charged me for a new tranny. Well worth the time spent searching here and under the car.

You guys are great! Thanks!

Majofo

Glad you're up and running again with more coin in your wallet.

I was hoping my DIY would help at least one member out.

McDuc

Helped me, and I suspect quite a few others. Sorry I spelled your name wrong!

Majofo

Don't worry about it.. Gay Barking Dog dude would be fine.

yogi799

Is your D5 still not blinking/fixed for good? I am struggling with a similar problem but have not gone to the dealer to pull the codes yet. Let me know please.

dougmckenna

I'm experiencing the flashing D5 light on my 05 MDX, with no other noticeable tranny issues. Initially happened about a year ago. My independent mechanic replaced 3rd and 4th pressure switches and it went away. Now occurred again. Code stated something like "High Input". Replaced the tranny Temp Sensor based on some leads on the interweb, but no luck.

Anything else to check?

Are there other pressure switches, 1st, 2nd & 5th, that could also go bad?

Thanks!

Majofo

What's the code? Probably TC related. No other pressure switches.

dougmckenna

My mechanic cleared it and didn't write it down, but he said it was something like High Input. I'm sure we will pull it again next week and get the specific number.

rjbush

Doug, did you get your issue resolved?