transmission won't go into first
12-28-2009, 08:15 PM
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transmission won't go into first This is for my 98 chevy pickup, it has a 4l60e. I noticed today that it doens't shift or downshift into first. It starts off in second. It seems to shift and run fine, fluid seems ok but it just won't go into first. Any opinions whats up with it? thanks guys.
12-29-2009, 10:32 PM
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No first gear. The vehicle should be scanned for trans function, basically .possibly one of two things are not happening.In first gear both shift solenoids must be on , in second one shuts off , in third the other shuts off , then in fourth the first (A) solenoid comes back on,So if A solenoid is not working(turning on) then you should also not have forth gear, If that is OK then the Electrical switch on the valve body should be for gear position when moving the shifter throughout the ranges. PRND4321 . IF the low switch is malfunctioning then the computer does not know that you are asking for manual first gear. so it takes off in second. Getting the trans diagnosed is half the battle. Also if the computor has set certain codes then the trans could be in failsafe which it is actualy takingoff in third to protect itself.
12-30-2009, 07:27 AM
#3
I have seen a broken plastic 1-2 accumulator cause an issue like this. Basically line pressure on one side of the accumulator gets into the 2nd gear accumulation circuit and causes a second gear start. If you are lucky and this is the case you might have caught it just in time. As mentioned above get it diagnosed asap. Feel free to give us a call if this trans is in need of a replacement. We currently have some great specials running. Vince www.finishlinetrans.com
12-30-2009, 01:43 PM
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Well I noticed today it don't go into overdrive too. I got the ecm tested and got these codes p0731, p0740, p0753, p0758, p0785, and p1860. so got to do some reasearch now.
12-30-2009, 02:10 PM
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Second gear start. SO the "A" solenoid is not working as well as other issues. as Vince said ECM and Power need to be checked. If B solenoid is working it uses the same power source ,it is the E terminal at the trans. We used to use a plug in Manual Box, This tool was used to shift the trans without ECM input to verify trans electrical function , Possibly your local Dealer has one. I think it was called a MI breakout box. The Tech 2 can also be used to Diagnose this.
12-30-2009, 02:25 PM
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not 100% percent on the solenoids and what they do but the codes say, shift solenoid A, shif solenoid B, shif/timing solenoid, TCC clutch circuit, and TCC PWM solenoid. You think this many can go bad or like you mentioned maybe a ecm problem? Where can I get these solenoids from if I need them? Thanks guys.
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12-31-2009, 07:28 AM
#8
I personally would verify the power to the trans and the wiring harness. One quick thing to do is to remove the main case connector and inspect it. Then replug it in and clear the codes. Then road test to see if the condition is corrected. See what or if any codes come back. I really still think your problem is there or in the computer. I believe replacing all the solenoids is going to be a waste of money because what is the chances of them all failing at the same time??? See my point and save your money. Find the problem and repair accordingly. Vince
12-31-2009, 09:02 AM
#9
As Vince mentioned you have a power issue fuse, wiring or harness plug to trans not a solenoid issue and not and ecm issue. Those codes are all setting because theres no power coming in on pin e in the harness for one of the above reasons.
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12-31-2009, 11:18 AM
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Ok i'll check that out. You know what the voltage is supposed to be at pin E? And which one is pin E? I think it should be the same as the 4th gens but not too sure, are they labeled? thanks alot guys.
01-01-2010, 08:57 AM
#13
Here is a picture of the case connector for you. Keep in mind that you will be looking at the vehicle harness to transmission connector.
You Could always drop the pan and check for power at the solenoids. Any of the internal harness wires that are red will be battery voltage. You will need to have the key in the run position to check for power. If you do this and do not find power as mentioned, either you have a power issue(blown fuse), one of the connector pins is open or your computer is messing with you. Hope this helps. Vince
You Could always drop the pan and check for power at the solenoids. Any of the internal harness wires that are red will be battery voltage. You will need to have the key in the run position to check for power. If you do this and do not find power as mentioned, either you have a power issue(blown fuse), one of the connector pins is open or your computer is messing with you. Hope this helps. Vince
01-01-2010, 04:39 PM
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Trans won,t go into first. Great now you have to trace back to the fuse box where the resistance is . Find what colour the E terminal wire is and go back to the the source . It is usually a pink wire. This is the "Engine Control" fuse 15 amp. you can use a OHM meter to check this circuit as well .
01-02-2010, 11:59 AM
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Ok wierd stuff guys. I checked voltage at the trans fuse on the dash, was getting 12v. Then checked the e pin again got between 7-8v. Then I unhooked the gauge cluster and instantly got 12v at the e pin. But it's still got the same problem. Wonder if somehow the gauge cluster fried the solenoids? Think the guage cluster is fooked. I guess my next step is to drop the pan and check for voltage at the solenoids. Also I had good contiunity between e pin and fuse.
01-02-2010, 12:07 PM
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Ok another thing i can check is to see if the vcm is actually grounding out the solenoids to make it shift. How would I go about checking that?
01-02-2010, 07:05 PM
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Ok did some troubleshooting today. I pulled my gauge cluster and magically got 12 volts to the e pin so think there is a bad ground in the cluster. But anyways I do have 12 volts to the solenoids, and I grounded them out and heard the click. So the solenoids are good, I got power. So i'm guessing it is my ecm? Thats really the only thing left right. and forgot if I mentioned but the truck starts out in second and shifts into third. Don't have first or fourth.
01-02-2010, 08:08 PM
#20
I personally would verify the power to the trans and the wiring harness. One quick thing to do is to remove the main case connector and inspect it. Then replug it in and clear the codes. Then road test to see if the condition is corrected. See what or if any codes come back. I really still think your problem is there or in the computer. I believe replacing all the solenoids is going to be a waste of money because what is the chances of them all failing at the same time??? See my point and save your money. Find the problem and repair accordingly. Vince
Ok did some troubleshooting today. I pulled my gauge cluster and magically got 12 volts to the e pin so think there is a bad ground in the cluster. But anyways I do have 12 volts to the solenoids, and I grounded them out and heard the click. So the solenoids are good, I got power. So i'm guessing it is my ecm? Thats really the only thing left right. and forgot if I mentioned but the truck starts out in second and shifts into third. Don't have first or fourth.
Also do you have a way to monitor your computer to see trans data? I'm curious to see if the a and b solenoid are commanded when you are in gear(forward range) wheels stopped.
Understand that the solenoids should see power any time the ignition is on. However in order to make them work a ground signal from the computer needs to happen. Where did you ground the solenoids in order to make them click?