98 (auto) gsx...Bad TCU? ### help

[GSXtacy724]

Just plain red? I dont remember seeing a all red wire, just the two mentioned man

ok Bender, I just connected the wire from the trans to the TCU and the car is still acting up. When I shift from park to reverse it shifts hard and the car wants to stall out. Going forward its still starting off in 3rd. I took the case off the TCU and everything looked fine. Looks like I gotta get a new trans....

 

[Bender]

The gray marks on the wire don't mean anything. I'm assuming you hooked it up to the gray spotted red wire on the end. You don't need to write the trans off just yet. Did you try pulling the trouble codes from it? The jerking into gear sounds like it might be a pulse generator. Also, what is your idle at in park? Putting a car into gear with a high idle causes it to jerk.

 

[Bluefire16]

Ive gone thru a bad TCU myself, my car was at my tranny guys shop for 3 weeks over 3 trips there ( 1 hour away) and we came to find out i had 2 BAD TCUS. I purchased one and it was bad, we did everything from "hotwire" the wires directly to the tcu to make sure there wasnt a bad connection somewhere. TCU's are a pain in the butt...

 

[GSXtacy724]

The gray marks on the wire don't mean anything. I'm assuming you hooked it up to the gray spotted red wire on the end. You don't need to write the trans off just yet. Did you try pulling the trouble codes from it? The jerking into gear sounds like it might be a pulse generator. Also, what is your idle at in park? Putting a car into gear with a high idle causes it to jerk.

No Bender, I found the all red wire and the wires went in the right color scheme that it was supposed to be. Was it supposed to go to a red thats not just red? I saw the wire colors on here but now cant find it. Should I connect it to the Red/gray dotted wire?
How do I pull codes? and it idles at like 1000, so its not higher then it should be..

 

[badas93tsi]

Yep, you're right. Good luck getting that mess of wiring straightened out.

 

[Bender]

Normally the gray spots (if I get what you are saying) are normally just length markings on the wires fro cutting needs. The wire you would need to connect to would be on the end of the plugs and be red (either with gray markings or not) Also, this is the wire that you ran to the transmission correct?

 

[GSXtacy724]

no. I wired it to the Red only wire, Should I wire it to the red wire with gray dots?

 

[Bender]

I will need to look at mine to see if it has the markings on it. All I know is that it is pin 1 on the TCU. I will try to snap you a picture as well.

 

[1993eclipseGS]

You are 4.5 hrs away. I have a TCU out of an auto 97' GST at my garage, ALONG WITH ALL wiring (everything still in the car), So if you need anything, Just let me know. I did not read basically any of your thread. I read your title, And see one page 1 you posted a big cluster of wiring. If you need help, Send me a PM and we can find out the problem and if you need any of this stuff to try, We can arrange for that.

 

[Bender]

^ Thats nice of him. I was thinking of doing the same thing, but you're kinda far. .

To get these cleared up, we are talking about this plug correct?

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Heres better pictures of the wires.

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And here is where they go.

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Go to the TCU. I removed some stuff so you can see it better. You may have better luck getting to it from the passenger side.

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Connect it to this wire on the biggest of the two plugs. Mine did have gray counting marks on it about every inch or so.

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[GSXtacy724]

thank you so much Bender! I will look tomorrow and hope the wire yours is connected to, is the one mine is not right now. I'll let you know tomorrow. thanks man, i cant thank you enough

 

[GSXtacy724]

Just looked and I have it hooked up to the same wire you are showing in your picture.....Now what? a TCU?

 

[GSTEE]

Bender, this is GSXtacy724. I forgot to mention when I put this tranny in, my starter wasnt reaching the flex plate, and I ended up having to use a 1g starter which DID work...dont know whats the deal

 

[Bender]

You will need to pull the trouble codes to see what it is. I just got the plugs in to make a 1g trans diagnostic reader, but I still need the obd2 plugs to make a 2g one.

Well you can wait till I get the parts in to make a 2g one, or you can do it yourself.

TCU Codes

 

[GSXtacy724]

that made my head hurt so i'll probably just wait . when you think you'll have em? and how much?

 

[Bender]

It is hard to tell. I ordered the plugs from Hong Kong so I could keep the cost of everything down, and I am awaiting their arrival. Probably going to be a few weeks though..

Get an LED from radioshack. Make sure it is a 12v one. (Most are 2-4 depending on color, and will require a resistor) Then touch the LED to the pins specified in the guide I sent you. Count the long pulses, and count the short pulses that follow. The long pulses are the 10's. The short pulses are the 1's. For example, 5 long pulses and 3 shorts pulses is 53. 7 long pulses and 4 short pulses is 74. Look up the number you get on the chart. The LED will cycle through your codes.

 

[GDNF2ET]

I know mines a 1g, but your shifter cable doesn't look like its mounted correctly..Here is a pic of mine...Hope this helps..

 

[GSXtacy724]

got the LED and resistor today. Im gonna try this after work tomorrow. I'll let you guys know. thanks

 

[GSXtacy724]

ok guys, so i used the LED ECU scan and came up with 5 short and 4 long, so in other words. a 45. Which happens to be...Codes (45,46)

* Check Solenoid Valve connector
* Check Pressure Control Solenoid Valve


Now what do you guys suggest I do?

 

[Bender]

You sure they weren't 5 long and 4 short? Or did you just say it backwards? The TCU's do the long one's first. If that's the case you have code 54, which is incorrect gear ratio. This would make sense if it was a foreign tranny for a different year.

If it is a bad pressure solenoid circuit, I would check different things. You will also have code 85 throw. It is automatically thrown if the trans is in limp mode by either code 45 or 46. 45 means it's open, 46 means it's shorted.

First thing I would do is check resistance, you do this with a DVOM, and touch one lead to the blue and yellow wire on the plug that I showed you earlier, and the other to a good ground. I recommend just unplugging the two halves that I have pictured, and touching the lead to the exposed pin. Be sure you are touching the transmission side plug. The resistance should be 2.6-3.2 ohms. If it is out of spec, you need a new PCSV solenoid.

Next I would check the TCU. On the same connector, only on the car side (instead of the trans side) check the voltage of the wire. Turn the DVOM to 20v, and touch one lead to the blue and yellow wire pin, and the other to a good ground. Voltage should be 1.5-2.0 volts. Make sure someone is holding the brake though when it's in drive.

 

[GSXtacy724]

i could have swore the short pulses were first...i'll check again tomorrow. I wouldnt doubt its the wrong trans...if I have to replace it, i'll probably make it a longer project and 5speed swap it

 

[Bender]

Try to get access to the DSMlink forums if you decide to do that. There are a lot of people over there looking to swap their fully built 5 speed setup for auto setups.