I just installed new capacitors and resistor in my tcu of my 1991 lx. And the car runs worse than ever before.

What caused my to fix tcu.

The s-light would randomly flash, not like it was displaying a code but more like there was a short some where. It would sometimes get bright and then slowly dim. Other times it would stay on solid. When it was solid it wanted to start from 3rd/4th gear. I would shut it off and it would go away and the shifting improved. But the last few times that I drove, it was going total bonkers. Down shifting randomly, sometimes on the highway, starting in high gear and the s-light would act up much more. I did noticed that when the light would come on that is when the problems with the transmission would happen. Also on the dash there is a section of warning lights that act up sometimes. They are the door/trunk/brake warning lamp. They flash and dim in a similar way that the s-light does, I don't know if this points to shorting or bad grounds some where or if it is related at all.There were no codes stored in obd. I took out he tcu and found a resitsor and a few capacitors that looked pretty bad, so I figured this was the problem and changed them.

I plugged the tcu back in, I didn't bolt it back in to it's frame I just set it on the floor it on the floor and started the car. It felt like it did't want to start but did. It started out in 2nd but didn't want to shift up and just felt like it was in neutral. I drove back home by manual shifting from 1st, 2nd. The engine light stayed on the car ran real rough and wanted to stall if it was in d4. Something also smelled real bad, maybe because it was running so rough. I got no codes.

What do you think happened?

Did I mess up the tcu? Damage the ecu when removing the tcu? Have really bad grounding issues?

 

I suspect you have problems other than TCU, but not sure w/ work done on TCU.

Suggest replacing your TCU w/ a used unit. Check car-part.com to find a unit near your zip code. I found plenty for $15-$35. You may need to order by mail for best price. Also check ebay for used TCU's.

Download a 91 Accord manual from Online Manuals links in DIY forum and check underhood grounds for good connections. Check battery and alternator voltage levels and connections.

good luck

 

One of the ecu harnesses got unplugged somehow and I didn't notice it at 1am, so the engine runs much better now. But I am having the same transmission problems. I unplugged the shift interlock module to see if that affected any thing which it didn't but after plugging it back in I can't shift out of park.

Anyone know about this service bulletin?

echnical Bulletin #:289
Transmission: PX4B
Subject: Wrong Gear Starts
Application: Honda, Accord
Date: Jan 1995

Honda Accord PX4B Wrong Gear Starts

• Starts in 3rd or 4th gear
• "S" light on, but not blinking
• No codes in computer (A/T control unit)
• Shifter interlock control unit buzzing

Check to see if your vehicle falls into any of these ranges:
U.S. Built 2 Dr Models up to VIN 1HGCB72 _ LA039050 U.S. Built 4 Dr Models up to VIN 1HGCB76 _ LA121350 Japan Built 2 Dr Models up to VIN JHMCB76 _ LC104599