doncello

I've mentioned this problem in an other post but there was no advise from anybody. So I decided to re-ask it. Maybe someone with knowledge see and advise me this time.

My car shifts from 1st gear to 2nd gear only in very high rpms 4k/5k when a/t is on d3 or d4. Other shifts are normal from 2 to 3 or 3 to 4.

Another interesting thing is if the transmission is on 2 the gear shifts from 1 to 2 normally.

For example if I'm driving in d3 or d4 and the transmission is stuck in 1st gear; can't pass to 2nd gear and if I bring down transmission stick from d3 or d4 to 2, it just shifts fine from 1st gear to 2nd.

Any advise will be really appreciated.

Thanks in advance.

MAD_MIKE

If you have selected D2 then there will be no shifting.
Something is goofed if you have a 1-2 shift.

Verify that the gear lever and indicator on the dash match.
Verify the gear indicator lamps on the dash function.
Verify there are no stored codes by jumping the two wire blue connector located over the passenger side kick panel, and watching the D4 or S light for blinking(codes).
Verify the battery connections are clean and tight.
Verify battery holds a full charge.
Verify engine bay grounds and bonding jumpers are clean and tight.
Look for any damage to the wire harness.

Transmission functionality is greatly affected by engine and engine sensor condition.
If the IAT, TPS or Thermo sensors are damaged, or reading incorrectly, they will affect how the ECU/TCU control transmission shifting.

If you have a voltmeter, turn the car to II(ON) and back probe the TPS, locate the output voltage signal. It should be a smooth linear voltage change with no breaks(opens) or erratic change when opening/closing the throttle.

doncello

Mad_Mike thank you for your interest in my topic.
What I was trying to say is when I'm on D2 gear shifts from 1 to 2 perfectly. But when I'm on D3 or D4 it only shifts after 4k-5k rpm. All the shifts from 2 to 3 or 3 to 4 are perfect both on D2, D3 and D4.

Gear lever and dashboard indicator match.
Lamps are functioning
There is no code related to transmission. Only code from egr which is there since more than a year.
I'll check battery connections again tomorrow.
I doubt battery holds full charge. (Also wondering how this can affect trans.)
I know one engine ground and will check it. (This one's affect on trans. also wonders me )
I dont know what is wire harness.

What I understood is I will disconnect TPS and attach a multi-meter into sensor and play with throttle, and look for smooth voltage change right?

So this problem might be rooted in malfunctioning TPS as I understood?

MAD_MIKE

AFAIK this transmission, when placed into D2, will ONLY be in 2nd gear. There should not be any shifting.

If you look at your car VIN(serial number) part of the identification will have 'CB*' What number is the '*'

If your car has the F18 carburetor engine with automatic, it uses a slightly different transmission than the fuel injected Accords.

Transmission is controlled by a computer. Up shifting and down shifting is controlled by electrical solenoids which are commanded by the transmissions computer. If the electrical connections are bad or weak, the transmission will not shift correctly.
In the engine bay, there will be a wire harness or loom that has wiring connecting to sensors and controls. Check that the wires are not damaged or cut, or disconnected.
No, do not disconnect the wire harness from TPS.
You need the wiring connected to the TPS.
Wiring to the TPS provides the voltage, TPS will change the voltage output.
Check the voltage output from the TPS by putting probes into the back of the connector to measure the output voltage.
You want to see what the computer sees when the throttle is opened and closed. If voltage change is NOT smooth, then there is a problem with the TPS or the wiring to the TPS.
There should be three wires. One will be 5V(power), one will be 0V(ground), and the other will be .5-5V(reference) and should smoothly change voltage as throttle is opened and closed.

doncello

OK I'll check TPS voltage and harness connections tomorrow since its midnight here.

The car is fuel injected.

Again I want to emphasise this because I think it can help a lot in diagnosing the problem. If lever is on D2 and if I accelerate the car gear shifts from 1 to 2 smoothly. But if lever is on D3 or D4 it only shifts from 1 to 2 at 4k-5k rpm. Thats whole my problem, there is no other problem in transmission, no error code, no blinking light, nothing.

I'll let you know about VIN number thing and update for other points.

Thanks again.

scubacamper

I had similar issues after warm-up and when I had the jumper plug shorted, I was getting the code for Transmission Shift Solenoid. Consider testing the solenoids too - although, my knowledge pales in comparison to Mad Mike - I'd do what he's suggesting.

doncello

I shorted plug and got code 15 i guess. The S light blinked one time long and 5 times short. I'm sorry because I said there is not any error code before.

Do you guys know what code 15 means in tcu. Also I used to remove, clean and put back Shift Solenoid Valve before, because of a wrong advise about engine. Is it possible I misconnected something or wrongly installed?

scubacamper

Is the SES light flashing or the D4 light?

doncello

S light

scubacamper

For others: is the s-light for the ecu or tcu?
The '93 accord gives two different sets of codes; one set for the engine/motor, and the other for the transmission - perhaps someone else can weigh in?

doncello

I don't know why my car starting throwing so much error codes. I just noticed the codes. I don't have any problem other than transmission shift from 1 to 2 on d3 and d4.

Can anyone help me in diagnosing these codes. It seems to me there is medium length flashing. Not long ones and short ones only.

Accord error codes:

doncello

I've reset the ecu. Now only error codes i get is 10 and 14 from ecu. No S or D4 flashing.
Problem persists :S

scubacamper

https://honda-tech.com/honda-accord-...codes-2630683/
Click there for a link to Honda OBD1 codes

Looks like 10 is for the air temp sensor (located on the side of the intake manifold, facing the master cylinder) and 14 is the IACV - perhaps a thorough cleaning is needed of the IACV, but likely a replacement (expensive part!)

doncello

Actually my only urgent problem is with transmission. Those codes were there since more than a year.

My problem again is on D3 and D4 only on 1st gear the rpm goes very high before it shifts to 2nd gear. For ex if on D3, gear stucks in 1 and rpm starts to go high and if I bring lever to 2 gear shifts to 2 smoothly. Problem is only from 1st gear to 2nd. And only in D3 and D4.

Please help me on this issue of you can.

Thanks.

scubacamper

If no one else gives you any ideas, I would suggest you go to Hondahookup.com - Honda / Acura Aftermarket Parts, Accessories, Forums, Photo Galleries, Racing, and more! and download a service manual for your car. In the service manual, there are steps to diagnose shifting problems, including testing things like the shift & lockup solenoids.

Also, check your transmission fluid level & integrity (does it look really dark & smell "burned"?). Sometimes just having low fluid levels causes shifting issues...

doncello

Yes I've checked the fluid level. Even it was OK I added more. What I don't understand is why everything fine on D2 (2 actually) but problematic on D3 and D4? I think this point can be the most helpful to find solution. I'm even willing to pay a small amount if someone can help me online. Because I don't trust mechanics.

scubacamper

I think what Mad Mike was trying to tell you is:
When you put the car into "2", it will ONLY drive in 2nd gear and will not do any shifting - the same is true with "1". But when you put it in "D3" or "D4", the transmission will shift between gears (or it should, anyway) at the proper intervals.

So, despite what you're saying, I don't think there's any relationship between your shifting issue and "D2"...unless I'm misunderstanding you.

The issue is likely in one of 2 places: The TCU itself is bad (there are tests for this in the service manual), or your shift solenoids are bad, misaligned, or not seated properly. Double-check your solenoids to make sure there isn't any T-fluid leaking around them, make sure the contacts are clean on the plugs, make sure the plugs are plugged in snugly, etc...etc...etc...

Also - you could try cleaning out the solenoids - there are instructions for this online as well.

doncello

I didn't understand why you say 2 drives only in gear 2. It can drive up to 2 which means 1 and 2.
What I'm trying to say is if lever is at 2(D2) if I accelerate gear shifts from 1 to 2. But no more than 2. But on D3 or D4 it doesn't shift from 1 to 2.

Am I missing sth?