Jeep Grand Cherokee Won't Start (Why And How)

By Nick Marchenko, PhD

If your Jeep Grand Cherokee won't start, there are a few things you can do to try and fix the problem. In this article, we'll take a look at some of the most common causes for this issue, as well as how to remedy them. We'll also discuss what to do if none of these solutions work.

So, What Are The Causes And How To Fix It?

Here we will tell you about the most popular problems with Jeep Grand Cherokee that don’t start and their solutions.

Battery Problems

If your Grand Cherokee's engine won't crank or is cranking slowly, the most likely issue is a weak or dead 12v battery. Doing a voltage test on the battery will help to determine whether it is indeed the source of the problem. These measurements should be taken between the positive and negative poles of the battery, as well as checking its acid levels and starter condition.

To find the voltage of your Jeep Grand Cherokee's battery, use a multimeter. First, set the multimeter to the right voltage range for your battery. Then connect its plus and minus poles to your battery's plus and minus poles respectively.

Generally, when you test your car battery's voltage, readings of 12-13 volts are normal. If the reading is above 14 or below 11.5 volts, this may be indicative of a defect that requires expert assessment. In other words: get thee to a mechanic post haste!

Corrosion

If you want to know if your Grand Cherokee's starting problems are from dirty battery contacts, lift the rubber covers over the two terminals and check for corrosion. If there is evidence of white deposits or silvery-green stains, simply clean the area - no replacement is necessary.

This problem may make your auto stop working as the voltage won’t be transferred properly, so make sure you remove any corrosion you see. You can use a mixture of water and baking soda to do this, just apply it with an old toothbrush.

Before you clean the battery on your Jeep Grand Cherokee, you have to disconnect the pole cables. This is a simple task that only requires focus and concentration, as the order in which you remove them is important. Start by unplugging the black cable from the negative pole.

If the pole clamp is very tight, open it with pliers. We advise against using metal pliers, but if you must use them, make sure not to touch any other parts of the body. Unplug the red positive pole cable. Once the battery has been removed from the circuit, start cleaning the corroded battery terminals. After cleaning, reconnect the cables.

Key Fob Battery Problems

If your key fob battery is weak or dead, it can prevent your Grand Cherokee from starting. To check if this is the case, press the button on your key fob to see if your Jeep's headlights turn on. If they do not, then it is likely that your key fob battery needs to be replaced.

To replace the battery in your key fob, start by unscrewing the back panel with a small Phillips head screwdriver. Once the back panel is off, you will see the battery inside. Remove the old battery and insert a new one of the same size and type. Screw the back panel back on and test your key fob to see if it works.

If your Grand Cherokee has a push start/stop button and it isn't starting, a weak key fob battery may be the culprit. However, even if the key fob battery is empty, you can still manually lock or unlock your door. You must open the doors manually. The immobilizer is passive, which means that the transponder does not need its own power source,  among other things.

Overall, a weak key fob battery is not a huge problem, as you can still start your car manually. However, it is always a good idea to have a spare key fob battery on hand, just in case.

Starter Motor

The starter is a motor for beginning the engine of your Grand Cherokee. Generally, it will last about 100,000 to 150,000 miles before wearing out--though using the car more regularly will shorten its lifespan. However, like anything else with limited usage time, it eventually breaks down after extended use and if that happens, the engine won't start up.

The main symptoms of a broken starter motor are:

• The clicking noise when you turn the key in the ignition, but the engine does not start
• The engine starts and then stalls after a second

If you experience either of these issues, it is likely that your starter motor needs to be replaced. This is a relatively simple task that can be done at home with some basic tools. However, if you are not comfortable working on your car, it is always best to take it to a mechanic.

If your engine does not start when you turn the key, it may begin if you simultaneously hit the starter motor with a stick or tool while turning the key. This often works when parts inside the starter are stuck together or gears are misaligned.

Fuel Filter Is Clogged

Your Grand Cherokee's fuel filter doesn't experience wear and tear like other mechanical parts; it becomes clogged with dirt, particles, and other debris over time. This gradually reduces the filter's permeability and lowers fuel pressure as a result. Keep in mind that if the fuel filter is entirely clogged, the engine will run less efficiently and may not start at all. You can't simply clean a filter - you must replace it.

A clogged fuel filter will often cause engines to sputter or run roughly when starting up. If you notice this happening, it is a good idea to check your fuel filter and replace it if necessary.

Pump Failure

If the fuel pump in your Grand Cherokee stops working, then the engine won't turn on. The purpose of the pump is to make sure that enough fuel can get from the tank and into the injection system of the engine with adequate pressure. If your fuel pump stops working, the engine will crank but not start. This is because the pump is not able to deliver fuel to the engine.

There are a few ways to test whether or not the fuel pump is working. One way is to check the fuel pressure at the rail. If there is no pressure, then the fuel pump is not working. Another way to test the fuel pump is to listen for it when you turn on the ignition - it should make a faint humming noise. If you don't hear anything, then the fuel pump may be faulty.

If your fuel pump needs to be replaced, it is best to take your car to a mechanic. Fuel pumps are located in the tank and can be difficult to access and replace.

Nick Marchenko, PhD

Industrial Engineer & Automotive Content Specialist

Nick writes in-depth guides on car clubs, engine specs, vehicle ownership, and modifications, combining engineering knowledge with automotive passion.

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