HELP!!! My 91 accord ex 4 dr sedan starting acting up transmission wise. It did go into limp mode. Read the threads regarding the failed capacitors and burnt up resistors. Seemed to have the "capacitor failure" disease by all accounts and symptoms. Pulled the TCU, replaced R41, R42, C5, C27, C28, C32, C33 figuring I'd cover all the bases to never have to deal with this again....put the TCU back in......my wife took the car to work - 7 mile trip - worked fine till about 6.5 miles and then went into limp mode. She parked the car and had to use the bypass release to get the car into "N" to start it to get it home. She said she smelled burnt electronics in the car. I pulled the TCU and R41 is burnt up.....again......so my concern is:

1) do I have another bad component like a transistor, diode, or voltage regulator on this module?

2) should I just go with a used or remanufactured module.....not knowing if something in the car wiring or transmission itself is causing the R41 burn up issue?

3) what is the likelyhood that there is a problem in the car causing the TCU to fail.

*****note....I replaced R41 again...put the TCU back in and turned the iginition key only a couple clicks but not enough to start the car...and in 3 seconds I had a smoking R41.....disconnecting the smaller of the two grey PJ connectors still has R41 getting smoking hot....but disconnecting the larger one results in no smoke......might just be that the power to the circuit board runs through the larger connector and the board itself didn't have powwer to it.....hence no electricity to cause R41 to heat up.


any and all adise appreciated.....thanks! Jeff

also....I did not discconnect the battery after replacing components and re-installing the TCU.......I don't feel that clearing the codes by removing power should also be necessary so the TCU doesn't burn up....seems that would be poor engineering.....but who knows......

 

My only suggestion is that the you try to figure out what component is upstream and downstream of R41. There may be another bad capacitor, bridged solder from one of the new capacitors, or damage to the board from a leaking old capacitor?

If you can't yours repaired, I would get one from a junkyard. Get one with a warranty. The site car-part.com searches junkyards by distance or price and is a useful site. I am a fan of u-pull-it junkyards.

 

thanks for the reply! Advice is always appreciated. I have been an electronics bench tech for 30 years...so I have done board component level repair for a while...and have checked for solder bridging already. Difficult to troubleshoot the additional failed component without a schematic however...and no parts list to order the parts should I find a bad one anyway. Did find a fella who repairs these and offers a lifetime warranty on eBay out of MN for $75 with a day turnaround...might be the best way to go and I did talk with him...he believes it is still a board failure issue and not in the car itself someplace...so might be good money spent to have hime take a go at it and get the lifetime warranty/insurance so to speak. Thanks again.

 

Check the connectors to the solenoids on the trans.....I forget which one but one of them is prone to get corrosion in it and cause repeated failure of the TCM.

EDIT: A bit of a read but here is one example of what I was thinking about: https://www.hondaaccordforum.com/for...f-48908/page2/

 

awesome....will do! thanks!!

 

Just a note to all who may read this thread......I have ordered a virgin pre-owned TCU with plans to replace the five electrolytic caps before reinstalling the TCU and a pre-owned ICU to install in my car.......I am also going to clean and/or hard solder the connections for the transmission solenoids to make sure those contacts are not an issue causing reoccuring failure of the TCU as suggested. I will post how the outcome of this service measure comes out.

 

Leave, add enough wire on the solenoids so they can be removed and "flip" them over for cleaning, they sometimes get dirty and need cleaning.

Or find a weatherproof two wire pigtail (of the proper wire size) and put that in place of the OE connector....I think that is what the other member did in the link I posted.

Yes, please keep us up to date on the progress and what comes of it.

 

update......connectors to solenoids in great shape......no work done to them. Replaced all 5 electrolytic caps on the replacement virgin TCU....installed it.....no sport light on and car shifts as it should.

replaced my integrated control model as I have no rear deffoger, int wipers, or dome light with a preowned eBay unit....no change....any ideas on what to try next with these common features not working? thanks!

 

When I look at the circuits for the rear defogger, intermittent wipers, and dome light; the commonality would be the Integrated Control Unit (module). However, since you had no luck changing it, it may be a power or ground connection problem at the interior fuse box.

The ground for the integrated control module is G402 (under right side of dash, near kick panel area) for a '91 Accord; but, I don't think it would be connection problem at the chassis end, as I would expect other electrical problems if it was. Power to the integrated control module come from a wht/blu power wire, protected by the number 22 fuse (15A) in the underhood fuse box.

 

awesome....I read the same from my chilton schematic...so I will check that fuse out as well as troubleshoot the power side if good on the fuse.......you know at 6'2", wrangling around under the dashpanel area on these HONDA's is such a treat!!!!!!....thanks!