akacivic

i have a 1991 accord ex automatic ,it starts up with no warning lights on only the green "S" is blinking..My speedometer works great but when i drive it hesitates on tranny..Someone said its the speed sensor but my speedometer is working properly..any suggestions would be appreciate it,,,thanks also

check engine light is working properly and theres no trouble codes..

blue91cb7

it's a bad tcu, its the smaller of the two computers for our cars

akacivic

but i dont understand..transmission was swapped cause when car warmed up it would drive no more only when it was cold or turned it off then back on....so i changed the transmission and now its doing this problem..didnt do it before...maybe transmission wasnt tthe problem..ill change tcm.thanks

Duane_in_Japan

Short out the two wire connector to check for S light codes that you use to check for CEL codes, I am guessing you did this, you did say there were no codes. Disconnect the TCM and shift manually and see how the car acts first. There are other sensors on the tranny also, not just a VSS. You still could have another bad tranny.

akacivic

HELLO THANKS FOR THE INFO BUT I GOT PROBLEM FIXED AND NOW IT WORKS GREAT,,NO MORE FLASHING LIGHT..VERY SIMPLE FIX..WASNT TCM OR VSS

Duane_in_Japan

As a noob you may not yet be aware that it is common curtousy to share what you did to fix your car so all the people that tried to help you can learn that what they suggested was correct or learn something new that they have not yet encountered, also not sharing will get you less help in the future, some of the guys do keep notes.

akacivic

ohh im sorry ,,i just went online and did more research and came out to be the lower sloenoid valve near the radiator(the one with 2 circles which is held by 3 10mm screws....i changed it with a used one and everything works great ..i took iot to work and it ran like a champ!!thanks everyone for the help..

Duane_in_Japan

Thanks for posting your fix, now it is in the archives.

s83dave

i hope that is the fix for mine...it is doing the same thing

Bad_dude

Instead of replacing I wonder if you could just clean it and it would still work?

s83dave

how would i go about cleaning it. i thought it was a sealed unit.

MAD_MIKE

http://techauto.awardspace.com/transmission.html

Have fun diagnosing.

TrilliamShatter

I have had the same issue for quite a while. I picked up a 91 Accord f22b1 swapped vtec auto. Intermittent s light flashing at first. . Then it turned constant, lost transmission shifting and looked inside tcu, fried parts. . Replaced with a used tcu from the newer f22b1 Accord and transmission shifts are smooth, but s light flashing. Cleaned the solenoid screens on all 4 still same thing. Tcu working fine and now I'm curious as to what may be causing my sport mode to not respond to the button and work. . Just figured id share and see if people know? And does anyone know if I replace my original ecu with the f22b1 ecu its direct plug in but do I need to change more pins than just the vtec? I actually ran for a while with old ecu from 91 engine but it's really rich. Vtec didn't work. So I hooked vtec up to ignition power and I have vtec but a bit more low low rpm bog. . Runs great now

MAD_MIKE

94-97 Accords did not have a 'sport' button or that function in the TCU. If you want to retain that you will have to use a 90-93 TCU.

.VTEC conversions have been covered in the Accord FAQ at the top of the page, lots of tech for you to chew on.

VTEC should not be connected at all times, it should only come online at the rpm set point. If it is always on the engine will try to run at the lower rpms on the big cam lobe which will cause it to run rough. The ECU is not programmed to run the engine at lower rpms with VTEC engaged. And a non VTEC ECU is not properly programmed to operate the VTEC engines. Timing, fuel and VE tables are all wrong for the engine. Either use the correct factory ECU for the engine or use a properly reprogrammed ECU for the engine. Do not try and force the engine to run an ECU not programmed for it. At best you will have low power and bad economy.

Nealva

Apparently Techauto let their domain expire. Does anyone have the material from the above link downloaded and can/will share it with me?

MAD_MIKE

Just wait til tomorrow, or whenever their monthly subscribtion restarts. They have the free site and after 5GB of data transfer awardspace.com kills their traffic. It'll be back up, site is usually down by the end of the month.

Jesús Vargas

How did you fix it? I have the same issues and you said it was a Quick fix. Thank you before hand for your help.

MAD_MIKE

If your S or D4 lamp are flashing, you will need to retrieve the trouble code that is stored in the TCU.
On 90-93 PGM-FI Accords there is a blue two wire connector that is located behind the passenger kick panel.
Pull it out.
Jumper with a piece of wire.
Turn ignition switch to II(ON)
Watch/count/record any of the warning lamps for blinking, write down the code.
Post back here for further help.

Norman Enz

How did you get this fixed?

Husqfan

I have done that and it gives me one long flash. I assume this means code ten. Any idea what code ten is?

Husqfan

an error code list for tcu would help me greatly. Anyone know?

Jonny Haerding

What did you do to fix it

Bryson Lohr

i just solved this issue on my 1991 accord lx 4door. intermittent flashing s- (limp mode.) could drive car once a day like normal until the dreaded flashing s would come on and had to drive in limp mode for a minimum of two days before it would go away. ran codes and got 1,2,3,5,6,7,8,14- started replacing sensors, vss, tps, o2 sensors, mass air flow sensor, cleaned iacv, new battery, flushed coolant system and refilled, recharged ac, cleaned shift solenoids a and b- nothing would help. after reading more of these forums decided to make a stop at my local pick a part and grabbed a tcu out of another 91 accord lx. installed it and voila! this was 3 days ago and have drove the car about 25 times, no more "panic mode" as my wife and i call it. i would suggest if you are having these symptoms, please start with the tcu!

Jesus Muniz

I have a 91 Honda Accord Lx, the s keeps flashing ever since the hurricane Harvey's becsuse water got in it. Drained it and kept flushing and redrain. But I have to put in gear 2 and go to D3. But D4 doesnt automatically kicks in so no good. Changed out the computer and lock and shift solenoid but still the samething. Any ideas peeps. Thanks.

MAD_MIKE

Check for stored codes.
P side kick panel, locate a two wire blue connector, usually hanging in space around there with no home.
Jumper the two wire connector with a wire.
Turn ignition to II(ON).
Watch the CEL or D4 lamp for blinking, long blinks are counts of tens, short ones are counts of ones.
Codes will be in numerical order. e.g. 9;15;41. not 15;9;23
If codes seem to be out of order turn ignition to I(OFF) and then back to II(ON) and watch the codes, they will repeat.
Engine issues/codes(even if the engine seems fine) will greatly affect transmission functionality.