Well if you guys have read any of my old posts on 4L60E to 700 i decided to fix my 4L60e and i replaced all solenoids, rebuilt the crapper, and still not fixed. Turned out the new 3-2 downshift solenoid was bad and got that replaced. Still Nada, nothing, zip. I purchased an atsg manual for this trany and thus my hunt for this problem's cause continues. The begining: problem is that i lost 1st gear and 2nd gear and overdirve. OBD2 codes said solenoids were bad. replaced all solenoids and still no 1-2- or ovedrive just third. Guys at work said hows the pan- I said dirty- they said rebuild and the problem will go away. I rebuilt it and still i only get 1-2-3 gears when i first turn the car on and engage D. then when i slowdown it does not downshift just stays in third. I can shift it down to 2nd but not 1st as it will not go into 1st just keeps 2nd. I also have no overdirve and I am getting really tired. The atsg manual said that i would only get third if the system voltage was high, Long system voltage high, 3-2 circuit fault or system voltage Low. Does any one know what this means? or where i could find the system voltage? my bat gauge allways shows 13 or a little higher and drops some when the fans come on but i dont believe i have a charging issue... any ideas? The trans control module is built into my ecu so do you guys think i need to verify my ecu is getting the 12 volts I dont really know what else it may be. I apologize if this is no longer relevant to this board as i don;t really know if it qualifies as a different subject... thanks for your help Ezra

I had a 2002 trans am one time that had a similar problem. it wouldn't down shift out of third when it came to a stop. i replaced the shift solenoid, same problem. a new valve body ended up fixing it. i'm not saying that's your problem, but it's just a sugestion.

Ezra:

Solenoid codes come in two flavours, electrical and performance. If you are getting solenoid circuit codes, you must consider not only the solenoid but also the wiring harnesses, and even the drivers in the PCM. Performance codes signify that the electrical end of things is okay, but the solenoid may be sticking, stuck valves, or mechanical failure of a hard part. Since you are able to get 1st, 2nd, and 3rd, you can rule out most things in the gear train. If you can tell me the codes you are getting now, I can tell you if they are electrical or performance codes. Also, the combination of codes and the order in which they are set goes along way to diagnosing the problem.

Hope this helps.

Don.

Thanks guys! Don at the moment i am still getting a P1886 wich would be the 3-2 downshift solenoid and i have replaced this unit twice. The first time i bought all the solenoids and the internal harness new and the 3-2 was bad. I forgot to ohm it out and it was bad from the factory. I replaced it again as it was under warranty and still no go. I still keep showing p1886 or 3-2 downshift solenoid malfuntio/ electrical. Thinking i may not be getting a good ground somewhere I i decided to ground my ecu directly to my battery. The trans control unit and ecu are in the same box and when i ran a wire from the neg term to the 4 ground wires in the ecu i got a greater voltage output on my alt! Now imagen that! All i did was hook up a better ground and my charging system was now reg 14.5-15.5 volts and when my fans kicked in it did not drop at all! (it used to drop to 11 or even 10 when they kicked in before and then slowly clime back to 13) Now my charging system is always above 13 and the engine is running better but the trans is still onbly shifting the grears the first time every time. I was thinking of replacing the valve body but the atsg manual says a high voltage or too low voltage will result with only 3rd gear.... so Im stuck and any further ideas to explore would be of great help!

Thanks again!

Ezra

Ezra:

Read my previous post again, carefully. I will emphasize, again, that a solenoid electrical code does not necessarily mean only the solenoid. It means the CIRCUIT!!!!!!!!!!!!!! The chances of a new solenoid being bad from the factory are very small indeed, and the fact that you seem to be having a run of them tells me that you have a problem in the wiring harness, or the driver in the PCM. I cannot emphasize enough that you MUST check the wiring harness going to and from the transmission. Your first post tells me that you did not do this, and your subsequent post says that you STILL have not done so, inspite of a recomendation to do just that.

Do this, and then get back to me.

Don

Thanks don. I will check tonight when i get off work. I get off at midnight and i will unhook the pigtaill off the trans and off the ecu and check for continuity. also how would i go about checking the ecu drivers themselves?I do believe i have an electrical prob as when i grounded my ecu directly to the battery i now get greater charging system output. *** knows i hate this crummy car I also have read of others wanting to use switches to control their 4l60e's any ideas on how i would go about this to manually check the solenoids and see if i can get it to shift as i drive?

Ezra

I have followed your instructions Don and last night i unhooked my ecu and began to ohm-out the individual circuits for each solenoid. the results were well within specs for each of the solenoids. B solenoid - 23.4 ohms; A solenoid - 23.4 ohms; 3-2 solenoid - 12.3 ohms; TCC 21.8 ohms, force motor/PCS 4.7 ohms. So them i installed the ecu and turned the car on. I then proceded to test the A,B,C range values in each gear for the transmission pressure switch. The range values were correct for each gear selected. Please adv me as to how to check the drivers for each of the solenoids as i now believe there are only two more options left. The drivers/Transistors that energize the solenoid for the 3-2 circuit is malfunctioning or i have a valve body problem. Please advise further course of troubleshooting/testing...

Ezra

Don i just wanted u to know that i wil be ordering a valve body tomorrow as one of my friends at oreillys can order one from dallas complete for about 65 dollars. What do you think? I don't have to buyit if i dont need it but i am having him order one just in case the drivers for teh solenoids check out ok and the remaining culprit would be the valve body i think... hope... I am also wondering if you know where i might be able to get a pressure line guage for this tranny and if i can just tap in to the pressurized trans cooler line to find out the pressure within the unit... please advise...

Ezra

I am back and i did figure out a way to test the drivers. Well sort of . SInce you may be busy and not checked into the thread lately i figured i could usem my DMM and hook one lead to the positive and since the ecu grounds the solenoids when they are active i should get a voltage reading when they are engaged... Well i did this and found that i can only check the first gear solenoid setup. A -on and B-on as when i put it in second i have first and second not just second and the same thing happened in 3rd and D.... so i drove the car around and then once it got stuck in third i pulled over and checked the A,B solenoids and found that B was energized and A only had 1.27 Volts... WTF I was in D so i down shifted to 1st as athis should energize both A and B... NOthing still the same B 12+ Volts A 1.2+ volts I am going to wire in my own switches for A and B and see if i ground them manualy what happens and i would also like to know if it is ok for me to move over to the electrical board as this is no longer directly transmission failure and maybe the guys over there might be able to give me some insight into what i should check on the ecu as when i disassembled it there was no burnt smell to indicate a circuit was toast.... I have canned the idea of the valvebody as this now appears to not be the culprit...

Thanks again for your help and please advise on further course of action... im at work right now and i get out at 12.00 AM CST i will be back to check any replies before i go home tonight.

Ezra

Well its almost time for me to go home and there have been no calls for the las hour or so an i was reading my atsg manual it looks like i am going to set up two switches to ground solenoids A and B and for 1 I will ground both, 2nd ground B, 3rd No grounds, 4th Ground A.... I have also been reading up on the DIY prom about 4L60E contollers and they seem to favor piggie backing a trans controller and harness but i dont think that is such a good idea for me.... I found out a new ecu for my car is 96 dollars and 70 to flash it so about another 200 and i'll have a new ecu but will that fix my problem ... I don't know and im really scrapping pennies here Sigh... I dont understand why when i turn the car on the solenoids work ok but then A circuit's stops responding as im olny getting 1.2+ volts once the bug happens... now this cannnot be due to the 12 Volt not being pressent but the grounding is just not working so... what to do.... the grounding circuit is stops responding but not completely as i still get some voltage reading.... so what does this mean?
Also by any chance does some one know what the black dot in the chevy sign mean? i noticed that my post seems to be the only one with this black dot? does this mean my post is specia? Well i guess im on my own here.... Wish me luck....

Edit-double post soory...

Ezra:

It is possible that you have a short across two or more wires in the wiring harness between the PCM, and the solenoids. As long as there are no shorts directly to power, or to ground, this would still give you the correct resistance readings when you test each circuit individually, but still cause enough interference to set your 3-2 solenoid code. It is also possible that a wire is broken inside the insulation, and giving an intermittent condition.

Also, could you please confirm that the code you are getting is indeed 1886, as I am unable to find that code in any of my manuals. In addition, is your vehicle a late 1995 production? The reason I am asking is 1995 vehicles still list the 2 digit trouble codes not the 4 digit OBDII codes. Unfortunately, there are always exceptions to every rule.

Don.

Yeah the code is indeed an 1886 3-2 solenoid circuit fault/ malfunction, and last night my idea of a manualmatic did not work... snifle snifle... i hooked up two switches from the A and B solenoid wires and disconected them from the ecu..... Nada, Nothi9ng ...I manualy operated the A B solenoids and i could not get it to go into first, second or third and even fourth while in Drive... i then shifted it to 1st and set A grounded and B grounded and No first gear just Second...WTF I thought that if i contrlolled A and B i could control the trans..... I can't?!!! WHY!!!! Do I need to diconect the other wires as well? or do i also need to control the 3-2 solenoid? Now im really pist and confused as the atsg manual showed the solenoids engaged for each gear and that does me no good..... Heheh i still get Reverse and 3rdin D, 3rd in 3 and 2nd in 2 regardless of which solenoids Aor B are energized ..... sigh.... valve body malfuntion?....



Ezra

PS my dsl at home is now working so ill be able to try any ideas and post much faster than before as i was doing all the posting from work....

Ezra:

Look in Your ATSG manual and check that the 3-2 downshift solenoid wires are routed correctly. On 1995 models, the 3-2 solenoid and the TCC-PWM solenoid( beside the TCC solenoid that is held to the case by 2 small bolts) are the same part number and it is possible to interchange the connections. The wires in the loom may be routed side to side. Your ATSG manual should show you which pins on the trans bulkhead connector go to which solenoid. If this checks out okay, and your wiring harnesses from the PCM to the solenoids check out okay, with no shorts to either power, ground, or other solenoid wires, your problem, by the process of elimination, is in the PCM.

Don.

What about tring to control the trans with switches? and the failure of my manualmatic V.001a ? I bought the harness for the trans new at the same time as the other solenoids as it came as one piece with the tcc lockup solenoid.... you think thi smay be bad? hmm ohmed out ok last time....You tihink it may be wired backwards from the factory? 3-2 actually hooked up tot eh pwm switch and the other way around? ok Ill look in to this but does my manual control failure mean anything? Shouldn't i have gotten 1,2,3, and 4th by controling Sol A and B? Please explain...

I kepttinkering arround (guting and rewiring|) with my manual switches and decided to remove the LED they had inside . It lights up to tell u its on, really helps as there is no way to tell on off other wise. and I got it to shift 1st, 2nd, and 3rd in D while switching The solenoids A and B on-off. Now i can get it to down shift from 3rd to second No problem but from2nd to f1st sometimes it wont shift down..... Valve Body? and sometimes even thought A and B are on I get first for about 2 seconds and then it automatically shifts to second? WTF I agree with you don that the PCM is ****ed but now i think the Valve body is ****ed too... as it won't obey my manual input... Any Ideas? I also don't get 4th even though i switch through the sequence a-b on-on; off-on; off-off, and then on-off should get me fourth but nothing.....this is payday is tomorrow and i will only be able to buy one part.... ecu or valve body? which first?


Ezra

not 100% sure but I believe that the pcm stops shifting the trans due to the 3-2 downshift solenoid code. the 4l60e fail safes to third gear both solenoids off. The wire harness may have broken wire that only has one or two strands still connected. the resistance will be correct but the wire won't be able to handle the load.

Do you suggest i remove the wirring harness from the engine/trans and ecu and rebuild the section of wiress that go to the trans and ecu? I just dont see how i would be able to tell if there were broken wires in the insulation.... I will look into this later this week as i dont have any days offf till friday and im broke from paying my bills Also yess i agree taht the wire will ohm out ok but won't be able to handle the amperage load of the solenoids.... My Manualmatic has also stopped responding to my manual control of the solenoids with regard to first gear.... I can't get first now for some reason and i can still get 2 and 3rd and downshift by using the switch on the B solenoid but nothing on A solenoid.... Also today while on my way to work i heard a loud pop and heard something crunch under my car... I dont know if i hit a rock or if something in my trans gave Ill check into it tonight off work. Any further ideas and suggestions are appreciated.

what i do to find a bad wire is give it a lite tug. If it is broke inside the insulation it will strecth and brake the insulation. then all you have to do is repair the wire that is broke. i would check all the other wires in the same area as the broken wire for any signs of problems.

One more thing. when you rebuilt the trans did you mark were the three small headed valvebody bolts went. they are slightly longer and can cause problems if they are installed in the wrong hole. I have only seen it once and it would cause no third on the hoist. I never road tested it though so I don't no what it would do on the road.

If you mean the crappy 8mm bolts i erplaced tehm with 10mm bolts as i stripped then when i took them out. I will take the harness off and check them and rebuild it if necessary.

Ezra

Ok guys im back and i have ordered a new valve body and valves. It will be here on wednesday and i guess ill see how this affects my trans. Its going to suck if this fixes my problem becasuse i spent a lot of money on this crapper and well im tiered.

Today i finaly got my VB as the shipper put the wrong address info and it got lost.... now i am also ordering the springs for the accumulators as i will be removing the shift kit that it has... wish me luck guys and thursday is when i will swap out parts.

HEll i got the VB in today and the POS did not do me any good I am back toi having first gear only when i turn the car on and Still no OD.... Im Pist I will try ordering an ecu but am also goin gto hard wire my A and B solenoids like before.... ManualMatic Retursn V. .02Beta... and see if at least this wayI can down and upshift as it will go up to 3rd but Not Downshift at all! any Ideas? Anyone?

Are you still getting the 3-2 downshift solenoid code? And have you verified all the wiring to the trans is good? Is it possible that the harness got caught between the motor and the trans? If you are still getting the code for the downshift solenoid you will have to diagnoise it. The computer will go to a fail safe if it sets a solenoid code.

Well guys i have checked the wiring harness and there is no problems with regard to connections so i did hook up the trusty Manula-Matic switches and i now have control fo 1-2-and 3 when i switch to 4th the tranny starts to slip so i think i screwed up when i put in the 3-4 Band control....I think as it seems the drum band is not holding for 4th... I ordered the ECU today and it arrives tomorrow so il have it flashed and then see what happens as i believe the dirvers for solenoid A si F*ked... It was still getting stuck and not grounding all the way.... It would only ground correctly the first time and there after only allowed 1.23 Volts to ground? WTF So I am replacing it and will be back with my resutlts

Ezra-

Well the Demon had finaly yielded (SP? ) and I have replaced the ECU and Tada I now have 1-2-3 and a slipping 4th on hand and as i slow down the trans downshifts correctly so when i stop, it get 1st again.... Ahhhhhh it has been so long since i actually made some progress on this dam thing I am really happy and would not mind treating you fellow memembers to a cold one on me Tonight! Too bad i don't know of any of u guys in the Lubbock Area... Well i believe i made a mistake in the orientation of the Servo when i put it back together and may have put it on backward as the trans shifts to fourth but all it does is slip like crazy I think the servo is not compressing the 2-4 band to hold the drum.... LOL Well ill take it apart he in a little while and flush all my fluid out and replace it with nice and clean fluid as i found it was cheaper to buy the Dextron III by the 5 Gallon bucket than by the case Case = 3 Gallons @ $22.39 VS. 5 Galloon Bucket @ $28.00 so Ill update on whether i did put the servo in backwards or not later tonight... nhte mean time any other ideas as to why it would slip when 4th kicked in? Any one?

Well i ended up changing the servo in the car with one out of my 700 i had lying arround and It turns out the one from the van Trany had a much larger apply area for the 2nd gear piston. I took pictures with my phone and will try to add them later.... Now with the better servothe problem is even worse as now when my tans shifts into OD it disengages 3rd but instead of just slipping like before it acctually starts to slow my car down as if i was using the trans to break! any one have any ideas as to what caused this to occur???? Also is the 4L60E really have 4 gears in it or is the OD actually in the Converter? Thanks for al your help guys...