Honda Accord Transmission Control Module

Needs replacing.

Fine. No problem.

Anyone have directions on HOW to do so.....????

Real problem....

thanks.
John

 

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.

 

1990

 

(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 thing?

 

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 everyones advice.

John

 

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.