Shift Issue | 1993 Chevrolet Lumina | 4T60E

93 chevy lumina big 300x246 PhotographThis 1993 Chevrolet Lumina came in with a transmission shifting complaint. The customer had a transmission issue and had a used transmission installed. After the installation the vehicle still wasn’t shifting right. I verified the complaint on a test drive and found that this car had no 1st or 4th gear. With the scan tool hooked up, I looked for any set codes and none were found. My next step was to verify the transmission fluid level, which was correct.

My next test was to use the scan tool and try to command shift solenoid A, shift solenoid B, and the TCC solenoid while listening for an audible click. I could only hear the TCC solenoid operating. According to the wire diagram, the TCC solenoid has it’s own power on pin A and both shift solenoids share a power on pin E. Seems like we have a power issue to pin E. I pulled off the connector at the transmission and inspected both halves of the connector for any corrosion or damage. Then I tested for power on pin A and E. Both pins had power. Now knowing I had good power at pin E I, had to do93 chevy lumina trans big 300x240 Photographfurther testing.

With the transmission connector still unplugged, I used my test light from battery positive to both shift solenoid control terminals (F and G) while commanding both solenoids with my scan tool. My test light lit up when commanding each shift solenoid. I now know that my power side and ground side are working correctly and that the problem is internal. I hooked my low amp probe around the shift solenoids power wire and commanded both solenoids just to check and see if I had any shorted solenoids. I found that there was no current flowing through either of the shift solenoid circuits.

At this point I either have a broken wire, backed out terminal, unplugged connector, two bad shift solenoids, or a combination of two problems behind the transmission side cover. I then proceeded to remove the side cover to inspect inside. What I found4t60e side cover diagram big 300x210 Photographinside wasn’t what I expected. With the cover off I found a few extra items and a few items missing. In 1993 there were 2 different 4T60E available. The old design and the new design. This car was suppose to have the old design but the used transmission that was installed was the new design.

The old design had shift solenoids A and B, TCC solenoid, and 1st and 4th gear pressure switches. The new design also has shift solenoids A and B, and a TCC solenoid. It does not have any pressure switches and also has a TCC PWM solenoid and temp sender. Only the TCC command terminal was the same. The TCC solenoid was also able to receive power on this car but if the transmission problem was the opposite (car that is suppose to have new style trans but had old style installed), it would not have had power. This is why the TCC worked when commanded with the scan tool. This car needed the right transmission installed.

old 4t60e wire diagram big 244x300 Photograph new 4t60e wire diagram big 300x233 Photograph

 

21 comments

  • matt hilderbrand says:

    thank you for this info i am working on a car now with almost the very same problem.thanks from matt

  • troy williams says:

    great info..have same problem thought i had a slipping problem,but trans doing exactly what u posted thks for info..and wire diagram..

  • George says:

    Is there an easy way to tell if it’s a new or old 4t60e design looking from the outside?

    I have a 93 I need to replace the tranny and want to buy a core to rebuild to minimize down time.

  • George says:

    Would it be safe to say that if I disconnect the transmission connector, turn the key to on, and read A & E. If both have power, it’s a newer version?

  • Tony says:

    I have a 1990 Lumina that won’t shift into 3rd gear, 1st and 2nd work fine just won’t shift into 3rd. Any ideas?

  • Corey says:

    When I switched out the solenoids in my 94 Buick century 3100 series. There was a pin/plunger looking thing that come out but not all the way, when I took out solenoid for the 1-2 gears. once everything was back together I still do not have 1st gear. Is there a deeper problem then just the solenoids?

    • Travis Dewitz says:

      What testing did you do? That was the valve that you most likely saw.

    • Corey says:

      Before I switched solenoids i had no 1st or 4th. After I switched them one was bad others looked fine. once it was back together I now have 4th back however, when i come to a stop I have to manually shift car into lower gear because it stays in 3rd or 4th (I cant tell). When we replaced the solenoids the one on the top left a small plunger came out but when we replaced the others none of them had this so I am wondering if this is the problem why it will not shift into 1st. and also why it will not shift down automatically.

  • Ed Arnold says:

    I have a problem with reverse if I dont give to much gas reverse works fine the more gas I give it it seems like it goes out of gear. any suggestions?

    • Travis Dewitz says:

      I need much more trans data to help but it sounds like a mechanical or fluid issue.

    • mike daniels says:

      mine did this today –first time i have ever backed up at a high speed–it was an emergency situation . I was thinking perhaps since reverse is about the lowest gear in the car that maybe the rev limiter was kicking in as that is what it felt like,like shutting down fuel flow intermitantly..any ideas would be nice though Hopefully inexpensive ones.Fluyid been swapped out every year religiously.

    • mike daniels says:

      by the way this a 94 beretta 3100 4t60e

    • mike daniels says:

      by the way this car is a low mileage 94 beretta 3100 with the 4T 60 E.

  • Ryan says:

    what does a new/good automatic transmission suppose to shift at in a 1996 Chevy Lumina?

  • mike says:

    I have a 1996 chevy lumina and the transmission wont shift into reverse or 3rd. any comments on this?

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