Honda Accord Transmission Control Module

What year of Accord?

Yes problem.

Are you absolutely sure that you need a new one? What are the indications upon which you base this decision? Is the dashboard gear indicator flashing? Is the LED on the transmission module itself flashing? If so, how many times?

There may be a problem with a solenoid connector. There may be a problem with the throttle position sensor. There may be a problem with the wiring. The transmission control module fuse may have given its life to protect the computer.

Had problem with this unit a couple of months ago.

Dealer replaced at no charge.

Perhaps it was due to the recall on odometer since the car had 53,000 on it and it should not have been covered by warranty.

(1) The 's' light does not flash, it is solid. (2) In cold weather it works fine, the hotter it is, the worse it gets. (3) It will start off in hot weather working mannually,, then will not shift out of second when it gets hot.

:-)

I guess I should have indicated that it is a 1990 and has 289,000 miles on it.

Dealer, I'm sure, would replace, but for more than I want to spend....

I assume that you mean the 'd' (for drive) light or 's' if the gear selector is in sport mode.

It might be that the shift selector linkage is out of adjustment or perhaps the throttle control cable needs adjustment.

It would be worthwhile looking at the error indicator on the transmission control module itself. If it's like my Prelude the TCU is under the carpet where the passenger's left foot rests.

There's usually a little flap of carpet up under the dash which you can pull back to look at the error annunciator for the engine control computer. In order to see the corresponding lamp for the TCU (to the left of the engine control computer you'll probably have to pull back the carpet. Loosen it up by removing the push-in fastener just to the left of that little flap of carpet. You'll also have to unfasten it from the kick panel on the right. If you reach around the panel you can feel where a hole in the carpet mates with a fastener on the back of the kick panel.

Once you can see the TCU, turn the ignition to the 'on' position. Starting the engine is not required. The LED on the module may flash briefly when power is first applied. Ignore that. If the LED lights after that, count the number of flashes which indicates where the TCU thinks the problem is. The error code will repeat and is retained even if the problem temporarily goes away. (It is reset by pulling the TCU sense fuse under the hood.)

While you're there also note if any error codes are being flashed by the engine computer.

Yes, somewhere north of US$400.

What's the condition of the transmission fluid? It should be pink and not smell burnt.

Fluid was replaced, it is pink, no out of the ordinary smell. It has been a very good auto. I bought a used ATM for 150 bucks.

Just reached my limit of tools, knowledge and physical dexterity....How do you unhook the bloody wires from this th>> I guess I should have indicated that it is a 1990 and has 289,000 >> miles on it.

simply press the tab and pull the plug. don't pull on the wires in case you break them.

As Jim says there's a button on the side of each of the connectors which you push in slightly to release the catch. I usually have to gently push it in with a lever of some kind release it and pry the connector out at the same time. The connector fit can be tight and it is difficult to get your hand in the right position.

Also be sure that the part numbers beginning with 28100 on the original and the replacement modules are identical. (The lot numbers can vary.)

Any flashing indicator lamps on the computers when you started the engine?

Folks...

Replacing the computer worked!

Shifts like a charm, you'd almost think it were new!

(til you look at it)

thanks for every>> Needs replacing.

If you're ambitious you can replace the half dozen or so electrolytic capacitors in the old computer. Then you'll have a working spare. Note that those capacitors are rated at 105C not 80C so they're a little more expensive. The parts will still be less than five dollars.

Where can you find a TCU error chart? Have a 90 accord ex with somewhat similar problems. Will drive fine when cold. When it gets warmed up it won't shift into gear. Had to park it and come back. LED is flashing 1,6,1,7,1,1,1,3.(I think)

Until you find a list online or somebody comes along with the Accord codes, I'll tell you what they mean for my Prelude (found in the service manual) which may be identical.

1 - lockup solenoid A fault 3 - throttle angle sensor fault 6 - shift position switch fault 7 - shift control solenoid A fault

It is unlikely that all of those individual components are failing. What is in common among them? Power supply? Ground? Some internal circuitry in the transmission control computer?

Why not clear the codes which may have accumulated over several intermittancies? Pull the 10 ampere alternator sense fuse in the engine compartment for 10 seconds. On my car it is labeled Clock. Reinsert the fuse. The stored codes have been erased. You should then see no flashing LED when you turn on the ignition switch. Make sure that you're looking at the TCU LED and not the lamp on the engine control computer. Then start the engine. Still no codes? Fine. Drive it until it fails and then note the codes.

that would be a little lucky. the ones i've seen have a good deal more fried than just a couple of caps.

The reason that it I'm guessing tired electrolytics is John's description of the failure mode. Problems develop after the automobile has been operating for some time. It could be temperature related.