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Jeep Renegade Won’t Start: Brake Locked (Causes and Solutions)

Picture this: it’s a weekend, and you’re all dressed up for your outdoor adventure or trip to the mall. You sit comfortably, ready to drive your vehicle, but your Jeep Renegade won’t start, and the brake is locked. What a frustrating experience! But don’t worry; this problem is generally easy to fix as long as you know the cause.

So what are the reasons why your Jeep Renegade won’t start, and the brake is locked, and how do I fix it? This issue can be due to problems with the battery, starter motor, solenoid, brake system, or ECU system. Of course, the specific solution will depend on the cause or causes.

That said, let’s discuss each of the causes in more detail and then the specific solution. This way, you will know what to check or inspect in your Jeep Renegade if it doesn’t start and the brake remains stuck. Once you’re done inspecting and determining the issue, you can troubleshoot without worrying about worsening the problem.

Black Jeep Renegade Parked Beside Wall

Why Your Jeep Renegade Won’t Start: Brake Locked

Generally, your Jeep Renegade’s brake remaining locked or getting stuck when it fails to start is a safety preventive measure. There are many reasons why this happens, but the most common ones are the following:

Battery Issues

It goes without saying that any problems with a car’s battery can lead to the failure of your Jeep Renegade’s starter motor to engage. It’s simply because the battery supplies the car’s much-needed power.

Several battery issues you will need to consider include:

Loose Battery Connections or Corroded Battery Terminals

Loose connections at your Renegade’s battery can impede the flow of electricity. This looseness can occur usually because of vibrations when driving. Meanwhile, corrosion in your Jeep’s battery is mainly due to exposure to moisture and battery acid buildup.

Aged Battery

As your Renegade’s battery ages, it won’t hold a charge for as long as it used to. It will also eventually degrade. Thus, an old battery will have difficulty delivering enough power to start your Jeep’s engine.

Faulty Alternator

The battery won’t also be able to perform its job if you have a faulty alternator. The alternator is responsible for generating the vehicle’s electricity. It charges the battery as soon as the engine starts running.

Therefore, a problematic alternator means your battery won’t charge, or the battery can run out of power quickly.

Your Jeep Renegade’s alternator might not function properly for many reasons. Its internal components wear and tear over time. The connections and wiring between the battery and alternator might also be loose, faulty, damaged, or corroded, disrupting electrical flow.

A failing or damaged voltage regulator is another common reason for a faulty alternator. This component maintains constant voltage output from your Jeep’s alternator to the battery.

Any issue with the regulator will lead to overcharging or erratic charging, so you’ll end up with a drained or damaged battery.

Starter Motor and Solenoid Issues

Your Renegade’s (or any vehicle’s) starter motor is primarily responsible for initiating the engine’s combustion process. It has several components, such as bearings, brushes, and armature. Any wear and tear present can make the starter motor less efficient.

And, like with the battery or most of your car’s parts, the starter motor itself can wear and tear in time. When it has reached its lifespan, your Jeep Renegade won’t start, and the brake remains locked.

Another reason your starter motor isn’t functioning as expected is an issue with its electrical components: the solenoid and wiring. Loose wiring connections, damaged wiring, and corroded terminals won’t allow electricity to reach the starter motor.

On the other hand, a faulty starter motor will lead to the failure of the starter motor gear to engage.

Brake System Issues

The whole brake system is composed of several parts. Any issue with these components can lead to your Renegade not starting and the brake not engaging.

Common issues with the brake system include a malfunctioning or faulty brake pedal switch, master cylinder, or inadequately filled master cylinder.

Faulty ECU (Engine Control Unit)

Your Renegade’s ECU manages and regulates several engine functions, such as ignition timing and fuel delivery. It can malfunction if there are any problems with the electrical parts connected to the Jeep’s ECU. That’s because of a disrupted communication between the engine and ECU, leading to the delivery of insufficient or incorrect signals.

Firmware or software ensures the ECU controls the Renegade’s engine functions correctly. If it’s outdated or corrupted, the ECU will malfunction.

An erratically behaving or completely failing Renegade ECU might result from several environmental factors. Constant moisture, extreme temperature, and vibration exposure can damage the ECU completely or some of its components.

How to Solve Jeep Renegade Won’t Start With Brake Locked

Now that you know the common cause of your Jeep Renegade failing to start with the brake locked, let’s start solving the issues.

Tighten the Battery Connections and Clean the Battery Terminals

When you notice that the connections are a bit loose, simply tighten them.

If your Jeep Renegade’s battery has corroded terminals, carefully detach the pole cables, unclamp their circuits, and gently clean off the corrosion (and any dirt present). You can use either a battery terminal cleaner or a baking soda solution.

Recharge or Jumpstart the Battery

Before recharging or jumpstarting a battery, check its voltage with a voltmeter or multimeter. Generally, a reading of around 12.6V is considered fully charged. If the reading is slightly lower, from 11.5 to 12.5, you have a weak or discharged battery.

In this case, you can simply recharge your Renegade’s battery. All you have to do is connect the charger per the manufacturer’s instructions. Then, set the charger to the correct charging mode and let your Jeep’s battery recharge.

But if you’re already out somewhere, jumpstart the battery using your companion’s car or a heavy-duty booster battery and jumper cables (view on Amazon).

Here’s how you can jumpstart your Jeep Renegade’s battery:

  1. Ensure your Renegade (and the other car) is in Park mode, the parking brake is engaged, and all electronics are turned off.
  2. Connect the jumper cable’s positive (+) end to your car battery’s positive (+) terminal and the booster or other car battery’s positive (+) terminal.
  3. Connect the jumper cable’s negative (-) end to your car battery’s negative (-) terminal.
  4. Connect the other negative end of the jumper cable to a solid engine ground.
  5. Start the other car’s engine or the booster battery, wait a while, and turn on your vehicle.

Replace the Battery

You must replace your car’s battery if you notice that it continues to discharge quickly. That’s because recharging or jumpstarting is just a temporary solution.

Likewise, it might mean that your Renegade’s battery has already reached its lifespan or has damages you might have overlooked. Your battery also requires replacing when the voltage reading is too low or below 11.5V.

That said, ensure you opt for a battery matching your Jeep Renegade’s requirements and specifications.

To properly replace your Jeep’s battery, do the following:

  1. Gently disconnect the negative cable followed by the positive one.
  2. Carefully remove any hold-downs or brackets.
  3. Gently lift the old battery out.
  4. Install your new battery by reconnecting the positive cable first, followed by the negative one.
  5. Replace the brackets or hold-downs and tighten them to secure them.

Replace the Alternator

To determine whether the issue is with the alternator, you will need to test for output with an ammeter or voltmeter. A faulty one will have a reading of less than 13.8V.

Now, if your Renegade’s battery isn’t working due to a problematic alternator, start by checking the wiring connections. If they’re loose, tighten them. You must replace the wires if you find any wear, tear, or corrosion.

For a damaged or dead alternator, you will need to remove it and replace it with a new one.

Tighten the Solenoid to the Starter Motor Connections Or Replace the Wiring

Like with the alternator, inspect the connections, terminals, and wiring between your Renegade’s solenoid and starter motor. Tighten loose connections and replace any damaged or corroded wiring.

Replace the Starter Motor or Solenoid

If the connections, wiring, and terminals look okay, test the Jeep’s solenoid. Simply apply power and check if it disengages and engages properly. When you see any malfunctions, replace the solenoid.

Whether the solenoid is faulty or not, I highly advise you to check the starter motor’s condition or functionality. Using a starter motor testing equipment or multimeter, check the motor’s resistance and electric flow.

The tool will show a particular reading and compare it to the manufacturer’s specifications to know if your starter motor is functioning properly or malfunctioning. If you have a problematic starter motor, the best solution is to replace it.

Top Up the Brake Fluid

If your 2018 Jeep Renegade won’t start and the brake is locked because of brake issues, you first need to check for brake fluid level. Open your vehicle’s hood, locate the reservoir, remove the cap, and check the fluid level.

Fill the reservoir with brake fluid up to the recommended level if you find that there’s an insufficient amount.

Now, what if you notice that the brake fluid level is dropping frequently or dropping at a quicker rate than usual? Then, there might be leakage, so it’s best to have a professional look at it to determine the exact issue.

Repair or Replace the Brake Master Cylinder

When you see any signs of master cylinder damage, it’s advisable to replace the said part. If you find any leaks, a professional can repair the master unit. However, replacing the master cylinder and the power brake unit is a better option.

Repair or Replace the Brake Calipers and/or Brake Lines

For damaged and leaking brake calipers and/or lines and sticking pistons, let a professional mechanic repair the issue. If it seems unrepairable, replace the problematic part/s.

Repair or Replace ECU’s Electrical Components

Carefully inspect any wires or connections associated with your Renegade’s ECU. If there’s corrosion or damage, replace it. If the connections are just loose, simply tighten them.

Reprogram or Replace the ECU System

If there are no issues with the connections or wiring and you still suspect that the issue is with the ECU, run an ECU scan using a scanner or diagnostic tool. Simply follow the manufacturer’s instructions and then compare the readings to know if there are any issues with the ECU.

If there are, you will almost always reprogram or replace the ECU system. Simply update the firmware or software to reprogram the system. For more severe problems, replace your Renegade’s ECU. Make sure it’s compatible with your Renegade’s specific model and specs.

Jeep Renegade Won’t Start With Brake Locked: Table Of Summary

Below is a table summarizing the general causes, specific causes, and solutions of a Jeep Renegade not starting with a locked brake that you can use as a quick reference.

General CausesSpecific CausesSolutions

Battery Issues
Loose Battery ConnectionsTighten Connections
Corroded Battery TerminalsDetach and Clean
Low-energy or Discharged BatteryJumpstart or Recharge
Dead or Too Old BatteryReplace
Faulty AlternatorTighten Connections
Replace Wiring
Repair Alternator
Replace Alternator
Starter Motor and Solenoid IssuesLoose ConnectionsTighten Connections
Damaged WiringReplace
Malfunctioning or Damaged SolenoidReplace
Malfunctioning or Damaged Starter MotorReplace
Brake System IssuesUnderfilled Brake Fluid TankTop up
Malfunctioning or Faulty Master CylinderReplace
Damaged Master CylinderReplace
Master Cylinder LeaksRepair or Replace
Brake Caliper and/or Line IssuesRepair or Replace
Faulty ECULoose ConnectionsTighten
Damaged or Corroded WiringReplace
Outdated or Corrupted Software or FirmwareUpdate
Malfunctioning or Failing ECUReplace

Jeep Renegade Won’t Start and Brake Locked, Solved!

With this guide, you will no longer stay in the dark when your Jeep Renegade’s brake stays locked because it doesn’t start. Remember that it’s best to have a professional look at the issue if you don’t have technical skills or trust your judgment. Also, like protecting your Renegade from snow and rain with a custom-fit durable cover (view on Amazon), all these issues are preventable through regular maintenance.