Open circuit in 91 Accord?
 

Hi All,

I've been having a host of problems with my 91 Accord Ex with an AT. Last July when taking the car in for inspection, the mechanic replaced the brake light switch saying the brake lights weren't working. Soon after this, the brake lights wouldn't turn off. I took it to a different mechanic and once again the brake light switch was replaced along with the corresponding fuse. The car worked fine for a while and I didn't have any more problems with the brake light switch.

Then about 1 month ago, the check engine light came on and the S light came on, and the car wouldn't shift out of 3rd gear. I thought this might be problem with the transmission control unit, based on what people on this forum had previously said. I replaced the tcu and the sport light went off and the car would shift appropriately again. But the Brake Lamp light on the dashboard came on so I'm guessing the brake light switch is broken again. Also the check engine light remained on.

I'm thinking that these two problems may be related. There might be a short somewhere that is burning the brake light switch and the tcu? I would rather figure out what is causing this problem than continually replace brake light switches and tcus. Any help is much appreciated!

I doubt the two problems are related.

The brake lamp indicator doesn't turn on due to a bad brake switch. It turns on due to a burned out bulb. Check to see if any bulbs are out when you hit the brakes.

The light that is turned on is for the brake lamp, and not the brake light that is for the emergency brake right?

When the check engine light and/or the S light turns on in your car, it means that the ECU or TCU detected a problem and stored a code to help identify and fix the problem. You are lucky that you guess right in replacing the TCU without troubleshooting first.

Do the procedure in the DIY section on How to get CEL codes and post the codes you find. Then we can give you advice on what is wrong.

Thanks for the advice.

The Brake lamp light (not the emergency brake light) ended up turning off after the second drive after putting in the new TCU. And the brake lights are working.

I got the CEL code of 41 which is for the O2 sensor heater. I'll try and get my hands on a voltmeter and ohmmeter this week so I can follow the procedure in the Haynes manual to check the O2 sensor.

I do have a follow-up question. When I checked for the CEL code, my sport light started flashing 1 short flash every few seconds (ie code 1). I cannot find a list of codes for the sport light. Does anyone know where to find such a list? One time when I turned the car on the sport light flashed the whole time, but every other time it has not.

Code 1 is Transmission Control Unit code for Lock-Up Control Solenoid A circuit fault; short/open in LU control solenoid A wiring, connector, or solenoid winding. Resistance should be 12-24 ohms.

The LU control solenoids are a pair ganged solenoids on front side of engine, just beneath forward of distributor. They are above a second set of solenoid valves, the shift control solenoid valves.

Suggest downloading the 91 Accord Sedan manual from the Online Manuals links in DIY forum.

good luck