atariwtf

1992 Honda Accord LX / Automatic Transmission

Was flashing TCM CODE 15 (before fix?)


Very erratic transmission behavior here out of the blue...

When I first start the car the transmission will work.... reverse, drive... any gear. After a couple minutes of driving it will pop out of gear (or maybe it's just no up/down shifting?) and then when you push the gas it will just rev without moving. If I turn off and on the engine a few times it will eventually function again, for another few hundred feet before doing the same thing.


- Keep in mind this is right after being on a smog dyno 4 times in a week.... (was having smog problems, had O2 sensor and catalytic converter replaced and it finally passed properly). Not sure if the smog dyno could mess up my transmission, or if it was just a coincidence and this is the time that the TCM decided to go.

After passing smog, we went straight to DMV, transferred the car to my gf, renewed registration and on the way home the transmission "broke".

In 240,000 miles - it's *never* had any sort of transmission problem, ever.

After reading a bit, I thought it could be the TCM...


I have enough electronics knowledge to pull and inspect the TCM so I pulled the TCM and there was one mildly leaking capacitor, (the 33uf @ 35V... I replaced with a 33uf @ 50V). The other capacitors looked OK from the outside so I left them be - for now. I have replacements for them as well.

After reinstalling the TCM I still have the same problem with the transmission, but the TCM code 15 no longer appears (on the D4 light: LONG SHORT SHORT SHORT SHORT SHORT). Instead, I just have a solid orange CEL / CHECK ENGINE LIGHT LIT. No flashing, just solid, and only when the engine diag switch by the passenger door is jumped.

The TCM / D4 light no longer flashes code 15. but it's still behaving the same.


When I pulled and reinstalled the TCM I disconnected the battery completely (negative, then positive). Maybe that wiped the code?

Any suggestions??


This really sucks... my gf is out of a car right now and with it being the 4th of July, nearly everything is closed (yards, used parts etc). It'll probably have to wait until this weekend.




Modified by atariwtf at 11:16 AM 7/4/2007

atariwtf

Update: I replaced the TCM with a junkyard version:

Denshigiken "3EX" 28100-PX4-731 6173 LOT NO 171


The PCB component layout is a little different, but it looks the same.

The original TCM was a xxxxx-xxx-721 model


I opened the junkyard TCM and it looks nice... no caps leaking, no burnt components. The car it was in was in a wreck (front end damage) so I doubt it was in the yard due to trans failure.


Doesn't matter though since it's doing the exact same thing with the "new" TCM.


What else could it be?

tech8

You might want to check the mainshaft speed sensor, which would have given the initial trouble code 15. Trouble code 15 can be caused by the following:

- Disconnected mainshaft speed sensor connector.
- Short or open in the mainshaft speed sensor wire.
- Faulty mainshaft speed sensor.

I would make sure the connector is tight first, then drive it around to see if it helps the problem.

Check this link out, go to transmission:

http://techauto.bravehost.com/

atariwtf

Yeah ^ that ^ is a VERY informative site as far as these types of problems go.

I'll have to locate where that mainshaft speed sensor wire is.


It's very greasy & grimy down there by the lower solenoid set... I might take some carb cleaner and spray it a bit and see what happens.

The car isn't close a hose right now unfortunately.

tech8

The mainshaft speed sensor is referred to as the NM speed sensor in the link I posted. It shows pictures, and describes the location.

Yes, a good cleaning may help.

atariwtf

degreased and pressure washed the entire area at the carwash... much cleaner, but still has the same problem.

I'll test and replace the solenoids this weekend and see how that goes.

atariwtf

I bought a subscription to AutoZone's alldatadiy.com (only $13/year with a discount I found on the net... maybe @ fatwallet??) so that I could access the TSB's for my car.

One of the TSB's lists instructions on how to make a special test light to hook into the cars TCU so that you can determine if the problem is in the TCU, the solenoids or sensors, or inside the transmission itself.

So I'm going to build that tonight & go through that process tomorrow.

I'll also pull the shift solenoid & lower sensor so that I can clean them up.

Apparently the shift solenoid gasket isn't a gasket at all... it's like a FILTER basket type of gaskety thing (or so the parts guy @ my local honda dealership described it).

So HOPEFULLY there is some crud in there that is preventing it from shifting properly.


Also, according to another auto-trans related TSB that I found on that alldata site for my car, it's possible that my ground from/to the TCU/TCM is bad. They give detailed instructions on how to perform that test as well.


I'll keep the thread updated with my progress & findings.

atariwtf

Transmission is still broke.


Here's what I did this weekend....


- Replaced ATF (dextron III/mecron). Drained, added 3 quarts, drove around a couple of miles (having to restart the engine every few hundred feet to "reset" the transmission to work again, and then drained and refilled with 3 quarts again. The original ATF that I drained was BLACK SLUDGE. The drain nut had grease caked on it that looked like vasaline.


- Followed TSB's and confirmed:

** Lockup solenoid is between 12-24 ohms (~15) , and "clicks" when 12v applied to either connection. (It works). Pulled it off and Filter/gasket is clean. Tested each connector Vs. body ground to get the ~15ohm rating.

** Shift solenoid is between 12-24 ohms (~15), and "clicks" when 12v applied to either connection. (It works). Pulled it off and Filter/gasket is clean. Tested each connector Vs. body ground to get the ~15ohm rating.


** NM sensor is ~586 ohms (should be 400-600.. so it's OK). I tested by using both connectors in the sensor (not against body ground) to get the ~515-586 ohm rating.

** NC sensor is ~586 ohms (should be 400-600.. so it's OK). I tested by using both connectors in the sensor (not against body ground) to get the ~515-586 ohm rating.

** Replaced the battery ground cable & connector with a new one.

** Replaced the battery positive cable with a new one.

Here's what I've noticed...

After driving for a 500-2000 feet, it will begin to slip. It definitely doesn't like going into (or attempting to go into) 3rd gear. But it will eventually slip and start spinning regardless if I go anywhere near 3rd gear or not.

The peculiar thing is this... if I pull over, turn off the key, wait 5 seconds and start the engine again, it will without fail allow me to drive again for another 500-2000 feet session as if nothing was wrong.

That really makes me want to think that this is some sort of electrical problem??


Or perhaps it's mechanical and it takes the 500-2000 feet for the computer to recognize there is a problem and go into safety mode? That would suck.


Tuesday I'm going to take it to a local honda dealership and pay them for the final diagnostic. I've replaced the TCM with a junkyard special, but it did the exact same thing (and the new TCM's caps and resitors looked fine) I suppose it could still be bad as well... I'm sure Honda will have a known working TCM and ECU to test with, so that will be worth the diagnostic fee if nothing else. Plus I'm sure they'll do all the pressure and vacuum tests to find out if it's internal or not.

Anyway, I guess I give up. I'll report back with what Honda says.

Georgethedad

I bought a 94 with 165000 miles last week and the drive belt (altenator and AC Compressor) broke today while my kid was driving it. After I replaced it I took it for a test drive and it felt like a slipping clutch even though it is an automatic. Now it will creep backwards if I put it in reverse and just idle, if I give it gas nothing happens. A couple of times it seemed like it was going to work but once you give it some gas all forward motion ceases. I thought I had a worn out transmission, and maybe I do but the tranny guy I talked to on the phone said it sounded weird. Maybe yours is just worn out too, or maybe not and I have the same kind of weird problem. I'll let you know what they say, if I can ever find this webpage again.

ipihuc

I have the same exact problem! I did all the same thing you did and still no luck so I got me a used tranny. Let us know what honda says, thanks!

atariwtf

It's at the dealers now.... waiting

atariwtf

DEAD TRANSMISSION...

they said the pressure readings were low and there is a rattling inside the transmission.

They think it is the forward pump.


1992 Honda accord LX parts for sale (sans transmission of course)

Georgethedad

My transmission was shot and the transmission shop said $2200 minimum for a rebuild. The people I bought the car from have an automotive shop and put a used one in for $700. They claim they had no idea anything was wrong with car when they sold it to me. Maybe not, maybe so, but it is running good now and they gave me 6 month warranty. The motor sounds very solid and the tranny pulls strong and shifts smoothly so I've got my fingers crossed.

atariwtf

Honda wants $1400 to replace the tranny with a used one from a dismantler. I could get one from a pick-n-pull type of yard for $200 and do the labor myself, but I'm about done with it I think. 240,000 miles... a car has to be sent out to die eventually right? Too bad... otherwise it's in pretty good shape. 2 owner car (1st was my aunt) well maintained. Just had timing belt & tensioners replaced about 5k miles ago. ::sigh::

tech8

If you can do it yourself for $200, I say go for it. It will probably last a while longer, or you can sell it far easier with a working tranny. $200 is less than most people's monthly payment on an auto loan.

ClmnZ

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by atariwtf &raquo;</TD></TR><TR><TD CLASS="quote">One of the TSB's lists instructions on how to make a special test light to hook into the cars TCU so that you can determine if the problem is in the TCU, the solenoids or sensors, or inside the transmission itself.

So I'm going to build that tonight & go through that process tomorrow.

</TD></TR></TABLE>

atariwtf, any chance I can get a copy of that sent to azsunfun@***.net? I've got a problem on a 90 Accord EX, and I'm going through some testing of the solenoids. Just thought I'd ask, thanks.

atariwtf

Mine is as 1992... 90/91 were a little different AT and TCM than 92/93 I believe.

The pinouts on the wiring harness may be different, which would result in different locations to use the test light. Just remember, you need to make TWO of those test lights.

Use alldatadiy.com discount code 8001292 and it should give you access for $12.95 (50% off?) ... there was way more information than I thought there would be. All the TSB's of course, but a lot of other information as well.

atariwtf

I can however tell you that to test the solenoids on my 1992 you do the following:

leave the solenoid mounted (unless you've already pulled it off, then test ground against the metal body of the solenoid)

set resistance to 200 (or something greater than 50) on your multimeter

unplug the connector for the solenoid

put the red wire from your multimeter on either one of the pins on the SOLENOID SIDE of the connector (not the wiring harness side), and the black wire from your multimeter to the BODY GROUND of your car (the little nut for your accessory ground by your battery is fine).

On a 1992 (and probably other years) the reading should be 12-24ohms. Mine were 15.5 or so.

Do the same test on the other pin as well.


SOLENOID TEST, STEP 2:

with the solenoid mounted to the grounded transmission, or grounded to the negative battery terminal, touch a wire connected to the positive terminal to one of the pins on the CONNECTOR SIDE of the solenoid... you should hear a clicking. If you don't . it's bad. Test the other pin in the same manner.


---------------

To test your speed sensors:

switch your resistance to something greater than 600.. my setting was 2000ohm.

unplug the connector, use the red and black wire on your multimeter to test both pins of the SENSOR SIDE (red on one pin, black on other) the resistance (on a 92) should be 400-600 ohms. If not, it's bad.

ClmnZ

I've done several things to test it, the solenoids test fine, both by operation and resistance test using DVM. I've installed a small light on each signal to each solenoid. The B solenoid wasn't getting a signal. I've checked the wires from the connector on the TCM all the way to the solenoid, it shows no opens or shorts, and reads at 17.6Ω. I have tested the solenoids both on the car before removal, with them removed and after re-installing them, no change both at 17.6Ω and 17.9Ω, ±.1Ω change at most.

I can get the car to error out without even starting the engine. I turn the key on, and shift the car to D4, so I would say that is not an issue with the mechanics of the transmission itself. If the car does start without an error, the car shifts/works perfect. I have done 2 fluid changes (3qts each time) just as a precaution but no change and the fluid didn't look bad either. I've tried on 2 more attempts at disconnecting the connecter at the TCM and reading the solenoid when I have the flashing light, but things still read good from the connector through the solenoid. When I plug the connector back in, it still shows a flashing D4.

I've decided my issue is my TCM and I'm trying to locate a replacement (1990 EX), any suggestions for where? Thanks for the replies.

zumer2007

Hey, folks, check out the discussion on Accord transmissions & TCMs at this site:
http://techauto.tripod.com/

Also, I've had a lot of success finding used parts at eBay, especially from these guys:
http://stores.ebay.com/HONDA-PARTS-HEAVEN
http://stores.ebay.com/HAP-Recycling


Modified by zumer2007 at 6:44 PM 8/10/2007

tech8

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zumer2007 &raquo;</TD></TR><TR><TD CLASS="quote">Hey, folks, check out the discussion on Accord transmissions & TCMs at this site:
http://techauto.tripod.com/


</TD></TR></TABLE>

The link was already posted above.

zumer2007

Oh... Sorry, I missed that!

There is also great information at the site about the "main relay" problem that can cause the TCM to behave badly. I have a 92 Honda Prelude with TCM problems (I thought), that now seems to be caused by a bad relay, rather than the TCM having burnt capacitors or resistors inside it.

zumer2007

Well, well.... It turned out I had TWO problems on my '92 Prelude. (We share a similar platform with your Accords.) My Main Relay needed resoldering AND the Shift Control Solenoid B on my tranny was also bad.

Resoldering the Main Relay got rid of several trouble codes, intermittent tranny problems, and my no-starts during hot weather problem. However, Code 8 still kept popping up. The good thing was now the problem would occur *exactly* at the shift point, rather than randomly before fixing the Main Relay. Before going further, I gave the transmission an oil change. Didn't fix the problem, but it needed the new fluid anyway.

I tested the shift solenoids using jumper wires, and all four (two on A and two on B) clicked with voltage applied. I did notice that one solenoid on the B-side sounded a little "weak", but it was still functional and it measured 15 ohms like all the other solenoids. Tested the wiring harness--all okay. So suspecting a faulty TCM at this point, I found a used one for $50.00 on eBay (plus $10 shipping) to swap out. No luck; still Code 8 would occur. My attention focused back to that "weak" sounding B-solenoid, and I found a new one at http://www.hondapartsdeals.com/ for cheaper than my local dealership. Got the part delivered in three days. Replaced it after dinner this evening, and now the car runs fine!! Sweet! I'm a happy camper now.

Anyway, I just wanted to share all this with you folks since I had a solenoid that both clicked with the 12v jumper applied, and also measured within normal range--yet it was still faulty and needed to be replaced.

laurab13

my same Honda is doing the same.except when I start my car and start to take off I can't take off in D4 or D3 bc all it does is Rev's up with it barely giving any gas and when it does,it's does slowly, I have to put foot on break and take it all the way down to 1st gear than second,then3rd and 4th.
when it's in D3,both D3&D4 both lights are on.. we have disconnected the battery and unplugged something that Utube told us to do..than hooked the battery up and plugged that wire back in.. D3 light went off while driving but I still have to drive my car like a manual.. I'm assuming it's just the TCU sensor.. the two metal selenoids look clean.. no engine lights show up on my dash at all which I was told is a good thing.. I do have a manifold leak though..
I wish I had the money for the TSB website your talking about... but hopefully here in two weeks I will..
let me know if you could help me pin point what it could be.. sounds like your car is doing the same.. thank you
and best wishes

MAD_MIKE

You cleared the stored code, that will not fix anything.

Next time the D4 light comes(when not selected) or blinks, you will need to find the two wire blue connector, or the OBDII port and pull the codes.
But since you have not mentioned what year car you have, this will make it a bit harder to help you with.