i just read a post about another honda with a sport light that blinks and i read in my owners book that such a thing could be a transmission problem. the thing is mine is not blinking and the few times it has its not regular or consitant. in fact the problem is not consistant. sometimes starting the car cold it comes in and some times it doesn't. other times when it is on it doesn't stay on for very long maybe 5-10 miles down the road and sometimes less. other times it will stay on till say i get to the walmart 4 miles from my home then we i come out and start back up it's not doing it. |When it does do it the car shifts down or doesn't shift up and other then that i havn't had any trouble with it shifting and i can drive it all day long and the light wont come on. this has been going on for about two weeks now and i am scared to drive to far. i'm a single mom of four kids and no other car so i really need some help here. Car is a 91 honda accord 4 door stationwagon.

 

Even though the "S" light is not blinking, it is indicative of a transmission related problem. The 4th generation Accords commonly had problems with the Transmission Control Module (TCM) or a solenoid. (Commonly, one or two resistors and/or capacitors gets blown inside the TCM, or a solenoid on the transmission needs replacement.) First check that the transmission fluid is up to level, and looks relatively clean.

Here are some links:

http://autorepair.about.com/li...i.htm

http://techauto.bravehost.com/

Jumper the service connector under your passenger dash side, to see if there is a trouble code. Count the blinks on the "S" light, and post the trouble code. It is different than the Check Engine Light trouble codes.

http://www.c-speedracing.com/faq/06.php

 

Wow thanks so much for the advice and helpfull links. my luck i would have paid for a new transmission only to still have the problem or worse. i'm about to go out and see if i can get the code. Any idea what is costs to replace a tcu and is it something that can be done at home. i do have some experience with working on cars.

 

ok i checked the thing and the light didn't blink out a code so now what? i know i'm testing the right thing so thats not the problem

 

It can be the TCU malfunctioning, since the light stays on intermittently at times. From one of the links I posted, it shows the TCU located under the passenger area. It can be done at home. If you open up the TCU and see burnt resistors and/or capacitors, those can be repaired with some de-soldering and soldering with new parts (only a few bucks). But, sometimes the TCU is still bad without anything looking physically burnt/blown. If you are unsure of your soldering skills, there are sites on the internet that sell replacement/exchange TCU for around $100 or so; or you can try a junk/salvage yard.

Hopefully, you can isolate the problem, without spending $ and replacing parts that are still okay.

 

ok i took me a couple of hours but i finnaly got to the at control unit and pulled it out. now i'm gonna see if i can get inside and see what is going on

 

so now i have the controll unit open and not only do i not see any visual defects but the thing actually looks brand new on the inside. Any other ideas????????

 

Sometimes the TCU looks physically fine; but, may still be faulty. It also could be some of the solder points may be bad.

To me, it still sounds like the problems are electrical and may relate to the TCU or a solenoid on the transmission, as the problems are intermittent.

For now, reinstall everything and make sure the connections are tight. Hopefully, it is something that was due to a loose connection. If you get the problems again, drive to a safe spot, shut down the car and restart it. The TCU may go into a limp mode when there is a problem; but, reset when you shut the car down and restart.

 

Here is a quote from one of the links I posted above:

"The 90-93 Accord is a modern vehicle that relies on the computer to determine shifting points to increase comfort and safety. Without the computer the transmission won't shift and the car will simply move at a snail's pace or will simply default to limp mode, which is either 2nd, 3rd or 4th gear. The symptoms are followed by the 'S' or 'D4' shifter status light on the instrument panel blinking or lights up.

If the car won't shift into correct gears and displays a self-diagnostic light most likely the fault is not with the transmission. Sometimes a clattering sound may also be heard in the cockpit. This may be the sound of the transmission interlock system misbehaving, which may indicate a bad TCU.

Do not replace the transmission without first confirming the situation electronically. The fault is usually the Automatic Transmission Control Unit (also known as the automatic transmission computer or TCU/TCM.) "

 

I just copied this quote

"read a post about another honda with a sport light that blinks and i read in my owners book that such a thing could be a transmission problem. the thing is mine is not blinking and the few times it has its not regular or consitant. in fact the problem is not consistant. sometimes starting the car cold it comes in and some times it doesn't. other times when it is on it doesn't stay on for very long maybe 5-10 miles down the road".

sure you got it, My car has a same problem I did open the T C M circuit board
and looked into it r42 (resistor) I guess has gone little brown.
I am not really sure that is the problem so I am asking your help.
please help me what actual component would triger the S light to come on always
your reply will sure help both of us... thanks in advance........

 

There are many things directly or indirectly related to the transmission that can cause the blinking "S" light. From the site I posted previously, here is a list of some of the possible areas based on the trouble code, when you jumper the service check connector.



You should jumper the service check connector and count the number of blinks from the "S" or "D4" light.

A brown resistor may still possible be burnt. Generally, a good resistor will not discolor inside the sealed case. The value of the resistor at R42 on the Printed Circuity Board (PCB) is 150 ohms. The resistors at R41 and R42 (both are 150 ohms), and a few capacitors nearby are the common ones to be burnt/blown in the TCM.

Your problem does not necessarily mean it is the same as accordingtomom, as her "S' light does not blink; but, comes on intermittently. She also cannot retrieve any trouble code.

 

my friend, Thanks for your suggestion about the resistors R41 and R45. There is a small correction of the ohms. The ohms are 15 not 150 for both. I opened the tcu unit and found R41 partially burned and the resistor was okay. Then I checked the capacitor and it had leaked and eaten away the printed circuit. I replaced the capacitor and Yipee! it is working. My s light is gone and the problem is solved. Both resistors I also replaced. My speedometer was not working for six months sometimes it works and sometimes it does not work. Looking to solve this problem too. Can you please help with this also?

 

I never mentioned anything about the resistor at R45 in my post. Sometimes you can use a slightly different value resistor at R41 and R42, and it will work too. I don't have a 4th gen Accord to look at the resistor bands to see the colors. I just remember R41 and R42 being the usual bad ones, and the resistors were something like 150 ohms. If they are 15 ohms, tell me which ones (R41, R42, R45?), for future reference.

Regarding the faulty speedometer, it can be due to the Vehicle Speed Sensor (VSS) on the transmission, or the printed circuit board for the speedometer.

If you do not get a Check Engine Light for the VSS, it may possibly be the printed circuit board for the speedometer. But, check that the connection is tight on the VSS anyway.

There is a separate printed circuit board for the speedometer that you can pull out, after you remove the instrument panel. You can try re-soldering some of the solder points, or you can just replace the speedometer printed circuit board with a used one.

 

I am sorry I mean to say R41& R42 not R45 so the value is for 41&42 are
15 ohms. also It was actually the capacitor and it was underneth
the PCB was burnt due to leak in capacitor which actually fixed the problem.
I had to re route the PCB layout to make it work, still I thank you for your help.

now your suggestion about speedometer, I have to work on it as I will take
your word. In my case I get the check engine light as soon as I get the
S light 1st. so you say it is VSS on the transmission. ok I will look at it
but wonder wher it is? I also want to know is ther any connection between the TCU and speedometer not working because at least the speedometer was working some time at least once in a day before working on TMC but now completly nothing, hope while fixing the TMC accedently did not effect the speedometer......can you please give me some suggestion...

 

The VSS is located on the transmission, by looking way down to the transmission between the intake manifold and distributor area. Go to the same link again; but, this time to 'VSS'. There can possibly be a connection with the VSS, the TCU and speedometer; the link has some info.

http://techauto.bravehost.com/

It may be a faulty VSS or the VSS connector.

BTW: Thanks for the info. on the resistors values at R41 and R42; I will use the info. to try to help others in the future.

 

hello my friend I replaced speed sensor but bad luck it did not work. 10 days Before installing, the speedometer worked for 4 times on diffrent days.
So I decided to connect the pin to find the problem I got the code 4 ( the S light
flash 4 times in small interval) so assume it is code 4. I looked into the list of code for S light, I found that " 4 is Vehicle Speed Sensor open or shorted - No signal from speedometer. " also my chech engine light come up after driving a mile. car key switch on or off I am geting 4 to 4.5 volts dmm reading between
black and orange and wonder how it is geting voltage while the wheel not turning also between black and yellow 12 volts.
so I have to think what to do next. If you have any idea please let me know.
Thanks for sharing the problem my friend.....


Modified by vedha at 4:38 PM 8/31/2007


Modified by vedha at 11:33 AM 9/1/2007