Modern automatic transmissions use hydraulic fluid, which is activated by solenoids, to shift gears. In the 4L60E, shift solenoid problems can cause a lot of trouble. The purpose of this article is to help you identify 4L60E shift solenoid symptoms. The good news is, that if you do have a bad one, they’re really inexpensive.
What do shift solenoids do in the 4L60E?
The short answer would be that the shift solenoids found within the 4L60E transmission receive instructions from the ECU/TCM to open and close. This is where the “E” in 4L60E comes from. It means electronic control. The shift solenoids are the means by which this control is physically achieved within the transmission.
Shift solenoids are relatively basic in design and principal. Simply put, the shift solenoid has a spring loaded plunger inside of it that will move transmission fluid in and out of different parts of the transmission. This action makes the transmission shift into different gears.
This movement is achieved through the creation of a magnetic field within them.
4L60E Shift Solenoid Symptoms
Here are the main symptoms of a bad 4L60E shift solenoid.
Failure to Downshift– The 4L60E will often fail to downshift if one or more of the shift solenoids are stuck open or closed. This is due to the fact that the transmission fluid cannot be rerouted to the part of the transmission that would be making the next move. To put it simply, it is stuck doing what it was doing when the solenoid failed.
Delay Going in Gear/ Between Gears– If there is a long pause between gear selection and engagement, it can often be attributed to a faulty shift solenoid. Furthermore, if there seems to be a lot of time between when the transmission exits one gear and enters another, than it’s a pretty good indication of a bad shift solenoid.
Inconsistent Shifting– Often when a shift solenoid goes bad in the 4L60E, it’ll cause a lot of erratic shift behavior. The transmission will skip gears. It also may act like it is trying to “find the right gear”. Or, to put it another way, it’s can’t quite settle on the right gear.
Stuck in Neutral– If a shift solenoid has failed entirely, that it’s entirely possible that the transmission will not work at all. In this situation the transitional will remain a neutral regardless of what gear you put it in.
4L60E Shift Solenoid Failure Diagnosis
Most of the problems that occur with a 4L60E shift solenoid are caused by the coil wire going bad in some way. It can go bad in a couple of ways. The plunger can also get stuck. We’ll cover the why and the how here.
You can test the solenoids with an OHM meter. You should be looking for 20-30 ohms of resistance. If no resistance is found, than you know that the solenoid is bad, and that it is broken. If the reading is less than 20 ohms than it’s probably melted. There’s more on both of those conditions and what causes them directly below.
Broken Solenoid Coil Wire– In the event that the 4L60E solenoid coil wire breaks, the solenoid will no loner be able to create the magnetic field. A broken shift solenoid wire is going to be caused by a lot of harsh vibration, or high voltage that’s out of the normal range.
Melted Solenoid Coil Wire– The results of a melted solenoid coil wire are the same as a broken one, the difference is going to be the conditions that caused the wire to melt. Whereas a broken coil wire is likely to be caused by vibration or high voltage, a melted one is going to be caused extreme transmission temperature or high voltage.
Plunger Stuck– The solenoid plunger is an area of failure in the 4L60E. Unlike when the shift solenoids are melted or broken, a stuck plunger can be repaired. Shift solenoids are not expensive. It would be a good idea to replace it if you can afford it. This will keep you from getting under the truck next time the plunger decides to get stuck.
A stuck plunger is almost always caused by dirty transmission fluid or debris in the case. You’ll have to replace the transmission fluid anyway, but it’s a good idea to go ahead and change the filter as well. This will really help increase the odds that you won’t be making this repair again anytime soon.
Broken/Stuck Spring– There is a spring in the shift solenoid that moves the plunger forward, when it is damaged that movement cannot happen.
4L60E Shift Solenoid Testing
Here’s a good video of a an average do it yourself testing the shift solenoids. It’s pretty helpful.