4l60e no 1st or 4th, ez tcu

[NickTransmissions]

I rebuilt my first 4l60e and installed in a 1994 gmc k1500. It has a 2500 stall converter and using a ez tcu to control it. I have no 1st or 4th. Starts out in second and shifts to third like normal in d or od. Torque converter locks up too. Just no 1st or 4th. I've replaced both shift solenoids. Ez tcu will say it's in low1 when I move the shift lever to 1, but still starts in second. Ez tcu says it in 1st and will normally shift to second then 3rd on the screen, but never was 1st at all, same thing with 4th. Reverse works fine too. I'm interested to see if anyone has experienced this. One thing I'd like to note is I used a good amount of the green goo on the checkballs when installing the valve body. Not sure if there's a specific checkball that's controls both 1st and 4th... maybe to much there? Also has transgo hd2 I'm gonna clean up the valve body from old the old 4l60e and swap everything over with a new transgo kit and hope it works. Maybe it's the ez tcu, or something very simple, I don't want to swap the valve body as I paid for a supposedly working valve body online.
Thanks

No first and no forth - sounds like sol A has left the chat.

 

[tuffy331]

No first and no forth - sounds like sol A has left the chat.

I have replaced the solenoids, sometime this week I'm gonna use a multimeter on the transharness and maybe try to ground both solenoids to put it in first..

 

[NickTransmissions]

I have replaced the solenoids, sometime this week I'm gonna use a multimeter on the transharness and maybe try to ground both solenoids to put it in first..

Yea, seems as though Sol A isn't communicating with the PCM and vise versa...Why didn't you replace the harness and all other solenoids at the time you replaced the shift solenoids or did you?

 

[Scooterwrench]

Isn't this the same symptom you get when the factory VSS goes bad or the ECM doesn't receive the signal? Does the EZ TCU use the VSS to shift like the factory ECM?

 

[618 Syndicate]

Yea, seems as though Sol A isn't communicating with the PCM and vise versa...Why didn't you replace the harness and all other solenoids at the time you replaced the shift solenoids or did you?

My symptoms continued after solenoid replacement. I was about to swap out the trans when I learned what I said earlier.

 

[NickTransmissions]

My symptoms continued after solenoid replacement. I was about to swap out the trans when I learned what I said earlier.

What post are you referring to? There's a few of them in this thread including one that talks about the 2-3 shift being mechanical - is that the one?

 

[618 Syndicate]

Not on a 60e. 2-3 is a mechanical shift in that it doesn't require power. 1-2 and 3-4 require power. I was informed of this when the 60e in my cateye blew the transmission fuse. I called TransDapt looking for a sbc/LS input shaft adapter and when I described my symptoms (only 2-3 and R) the dude on the phone told me to check the fuse. It was blown (I'd used it to piggyback the power for my helper bag compressor) and as soon as I replaced it it was back to normal functionality. I'm forever grateful for his help.

What post are you referring to? There's a few of them in this thread including one that talks about the 2-3 shift being mechanical - is that the one?

Yes, I quoted it above for ya.

 

[tuffy331]

Yea, seems as though Sol A isn't communicating with the PCM and vise versa...Why didn't you replace the harness and all other solenoids at the time you replaced the shift solenoids or did you?

I replaced the harness when rebuilding. Only replaced both shift solenoids after finding 1st and 4th weren't there. The solenoids that came on valve body when I got it where all brand new. If you've experienced a 3-2 solenoid or another one that can cause no 1st and 4th then I'll replace the rest of them. Don't have a lot of money. I'm open to the suggestion of being 2 separate problems, but I don't believe that to be the case. I'm gonna ground both solenoids with a switch and read it with a multimeter to make sure it's grounding, maybe it'll go in first maybe not but itll lmk if it's the harness, tcu, or something internal. And I do have all signals such as vss, rpm and tps
Thanks

 

[NickTransmissions]

Yes, I quoted it above for ya.

A fuse can do it, it's one of many causes but the bottom line is that Shift Sol A is on in first and fourth, shift sol B is on in 1st and 2nd, off in 3rd and 4th so if he's missing 1st and 4th, its due to shift sol A not performing or being enabled to perform, hence "left the chat"

Why it's not performing is the question.

Also, the 2-3 shift is not "mechanical" per say as all forward pattern shifts happen under the direct command and control of the PCM and it's trans control strategy logic. It just so happens 3rd gear occurs when both solenoids are off but they are off because the PCM commands both off, not for any other reason, when everything's working correctly.

I replaced the harness when rebuilding. Only replaced both shift solenoids, the solenoids that came on valve body when I got it where all brand new. If you've experienced a 3-2 solenoids or another one that can cause no 1st and 4th then I'll replace the rest of them. Don't have a lot of money. I'm open to the suggestion of being 2 separate problems, but I don't believe that to be the case. I'm gonna ground both solenoids with a switch and read it with a multimeter to make sure it's grounding, maybe it'll go in first maybe not but itll lmk if it's the harness, tcu, or something internal.
Thanks

If you rule out all electrical/electronic causes (including the PCM itself), by whichever means, then it's time to drop the valve body...

Beyond that i cant let you know anything as im not there with you. But if i was, id check the fuse like 618Syndicate mentioned, test the solenoids then harness then vehicle harmess and pcm for voltage and continuity. Id then take it for a drive with a scan tool showing live trans data and command it into 1st to see if the pcm responds. If it does, pcm shows im in first but im actually in second then im looking internally into the trans.

Pre-96 4L60Es can shuttle back and forth between 2nd and 3rd while in limp mode. I rebuilt a 93 for someone years ago and installed a solenoid that was bad out of the packaging. He had the same symptoms you do. Just remembered this as i was typing.

Lastly- make sure you have a 93-95 3-2 control solenoid, not a 96-08 installed. Shot in the dark but that could also cause your problems.

 

[tuffy331]

A fuse can do it, it's one of many causes but the bottom line is that Shift Sol A is on in first and fourth, shift sol B is on in 1st and 2nd, off in 3rd and 4th so if he's missing 1st and 4th, its due to shift sol A not performing or being enabled to perform, hence "left the chat"

Why it's not performing is the question.

Also, the 2-3 shift is not "mechanical" per say as all forward pattern shifts happen under the direct command and control of the PCM and it's trans control strategy logic. It just so happens 3rd gear occurs when both solenoids are off but they are off because the PCM commands both off, not for any other reason, when everything's working correctly.


If you rule out all electrical/electronic causes (including the PCM itself), by whichever means, then it's time to drop the valve body...

Beyond that i cant let you know anything as im not there with you. But if i was, id check the fuse like 618Syndicate mentioned, test the solenoids then harness then vehicle harmess and pcm for voltage and continuity. Id then take it for a drive with a scan tool showing live trans data and command it into 1st to see if the pcm responds. If it does, pcm shows im in first but im actually in second then im looking internally into the trans.

Pre-96 4L60Es can shuttle back and forth between 2nd and 3rd while in limp mode. I rebuilt a 93 for someone years ago and installed a solenoid that was bad out of the packaging. He had the same symptoms you do. Just remembered this as i was typing.

Lastly- make sure you have a 93-95 3-2 control solenoid, not a 96-08 installed. Shot in the dark but that could also cause your problems.

Since you mention it, I put a 1996 pwm pump, and 1996 valve body with the 1996 separator plate in 1994 case. Id imagine the valve body i got should have all 96+ solenoids for the ones that year matters. I did notice the shift solenoids that where replaced where the old style. But I'm controlling it with a eztcu so it really doesn't matter what year the tranny is as long as it's not 2009+. And my first post has the info where a tcu is commanding low 1 but not going in 1st. Same thing with 4th, it gives me a live data screen. Fuse is good, I took it out the other day to check the ignition switch. The ez tcu will say comm error when 12v switch is lost