Jeep Grand Cherokee Shift Solenoid Problems and Possible Fixes

Nearly all generations of the Grand Cherokee will have a very specific common problem with their automatic transmission. This is the issue with the shift solenoid that results in a check engine light, glitching transmission, bad shifting, slipping, etc. But the problem is not always in the solenoid and repairing the transmission is not always just replacing this part. It's much more complicated than that, especially in high-mileage cars.

In short, the problems with the transmission shift solenoid in the Jeep Grand Cherokee are hard to locate and repair, also their signs may also signal some other problems in the transmission. These problems are common for the second, third, and fourth generations of the Grand Cherokee with 4-speed and 5-speed automatic transmissions. Maybe, the first-gen Jeeps are also affected but I have little information about them.

The 545RFE transmission is one of the most common in all those three affected generations, but the various 4-speed transmissions also show this problem.

Let's see why it happens!

What are the symptoms of the shift solenoid problem in the Grand Cherokee?

First of all, we need to understand the symptoms of these problems. You can't ignore the issue because your transmission becomes very hard to operate. It glitches all the time and doesn't work properly, at least when the check engine light is on or the transmission is in the limp mode.

At first, the transmission problems are interval. They start torturing the vehicle, you stop it, turn off the engine, wait for some time, then start the engine and it's now OK. But after some time, this simple fix doesn't help you anymore and you need to go to professionals and have the transmission inspected.

Here are some symptoms that may tell you about shift solenoid issues:

• your Grand Cherokee transmission start slipping - the RPM goes up on highways but the speed is the same or even drops;
• the shifting becomes harsh or happens randomly without taking into account the RPM or road conditions;
• the check engine light will most likely go on because the ECU and TCM control the solenoids and their work;
• your transmission may go to the limp mode and can only go in one gear or require manual shifting;
• your ECU will throw several codes that are all connected to the transmission, but the solenoid code may still not be there;
• things may change quickly - one minute the transmission is glitching heavily, the other minute everything is OK.

If this is the case in your Jeep Grand Cherokee, you should immediately react and address the problem. Driving your car with this issue is possible for some time, but no one can say when the car leaves you stranded on the side of the road. So, it's always a good idea to just go to the repair shop and have the transmission tested and inspected before it's broken completely.

You shouldn't think that Jeep has very bad solenoids in its transmissions. All transmissions are very durable and can go over 200,000 miles without many problems. But after that, the solenoids are actually the first parts that will die and cause problems in these transmissions. Also, poor maintenance may be the reason.

Why do solenoids die in Jeep Grand Cherokee transmissions?

Up to the 2004 model year, the solenoid pack in Jeep Grand Cherokee transmissions wasn't really reliable and could fail. In 2004, Chrysler started using a better solenoid block but I still can see some reports about the problems with it. My estimated mileage mark for this problem is 150,000 to 200,000 miles. But the solenoids will almost always be the first part to fail in these transmissions.

So, the shift solenoid is basically the electronic-hydraulic part that ensures that the flow of the fluid in the classic automatic transmission is adjusted according to the current tasks of the transmission. In most Grand Cherokee transmissions, you will find two shift solenoids and one closing solenoid.

The first shift solenoid is the one that fails, in most cases. Here are some reasons for this:

• the solenoid may fail when the transmission has inappropriate or contaminated fluid;
• also, failure is possible when there are problems with wiring or connections;
• very often, the solenoid fails just because it doesn't live longer than 200K miles or something like that;
• the more you drive in the city traffic, the shorter the life of the shift solenoid.

So, you see that prolonging the life of the shift solenoid in the Grand Cherokee is easy - you should just change the fluid and the filter in your transmission regularly. If possible, adjust your driving habits to avoid driving for a long time in traffic jams and classic city traffic. The less your transmission shifts between the first two gears, the longer the solenoids live.

Can you repair the shift solenoid in your Grand Cherokee?

Actually, it's not that hard to replace the solenoid, but before that, you need to make sure that you are doing the proper job. Very often, it appears that all these symptoms are connected to some other problem with the transmission or even with some electronic modules. It means that proper diag is needed before you invest some money and time in repairs.

Also, I don't recommend any DIY repairs with your transmission. The automatic transmission in the Jeep Grand Cherokee is a very complicated mechanism and it requires proper experience from anyone who approaches it. I can describe the process of shift solenoid replacement but I won't because it will only make things worse, in many cases.

So, you can repair the transmission in a professional repair shop after proper diagnostics. Any DIY repair is not recommended!

What else can cause the same symptoms?

You should know that the automatic transmission in your Grand Cherokee is not eternal. Sooner or later, it will anyway die and require some repairs or even replacement. But even if you register all the symptoms that I described above in this article, it doesn't mean that the only possible culprit is the solenoid.

Here are some other problems that can cause the same issues:

• low transmission fluid - in this case, the fluid will not form the needed pressure, and the transmission will glitch in all possible ways;
• bad fluid pump in the transmission - another possible issue for low pressure and all the possible issues with the transmission;
• bad TCM - the transmission control module, if presented in your car, may malfunction and cause all those kinds of problems and errors;
• the ECU - the engine control unit can also cause some issues with the transmission;
• wiring and connections - the solenoid may be disconnected because of a failed wire or broken connection.

There are also other possible issues that can lead to solenoid failure or to the symptoms that openly point to solenoid failure. That's why you should start with professional diagnostics and only after you find the actual reason for all these symptoms, you can think about the way to solve the problem.

Can you drive with the shift solenoid problem in the Grand Cherokee?

Well, the short answer is yes, you can drive when the shift solenoid is malfunctioning in your transmission in the Grand Cherokee. But if the solenoid is completely dead, you shouldn't torture the transmission.

You can still drive using the manual shifting mode or driving in the limp mode when the transmission doesn't shift gears and only uses the third gear or the second gear to let you drive slowly.

In any case, I recommend driving directly to the repair shop that can help you or to the dealership. If you think that you can drive another week or two, then no, this is obviously not a good idea. Most likely, your transmission will die and require replacement after such experience.

When is it too late to repair the transmission?

The majority of transmission types in your Jeep Grand Cherokee are pretty durable and can live over 200,000 miles. But if they fail after that, it usually doesn't make sense to just replace the solenoid and expect them to go another hundred thousand miles.

If the solenoid fails at about 100K miles, it's a perfect solution to just replace it and happily drive at least the same distance. But if the mileage of the transmission is huge, you better think about overhauling and rebuilding the transmission or maybe replacing it. Because after you deal with the solenoid problem, there will be another set of problems that will require immediate repairs.

Final thoughts

I still think that the Jeep Grand Cherokee has mainly good and reliable transmissions. The shift solenoid problems are not that hard to solve. Other than that, these transmissions will just require fluid can filter change according to the manufacturer's claimed interval and that's all. But if the mileage of the transmission is huge, you better avoid replacing the solenoid. One of the best scenarios is to find another transmission for replacement with lower mileage on it.