The auto start/stop (ESS) system in Jeep Cherokees is designed to enhance fuel efficiency and reduce emissions by automatically switching off the engine when the vehicle is stationary and restarting it upon brake release. However, several factors can cause this system to malfunction.

Causes of ESS Malfunction

• Intelligent Battery Sensor (IBS) Malfunction: The IBS monitors battery voltage and communicates with the ECU to determine when to activate the ESS system. A faulty IBS can lead to incorrect voltage readings and disrupt system operation.

• Battery Issues: A weak or failing battery can prevent the ESS system from restarting the engine due to insufficient power.

• Starter Motor Problems: A faulty or worn-out starter motor can struggle to crank the engine, hindering the ESS system’s ability to restart the vehicle.

• Alternator Malfunctions: A faulty alternator can lead to insufficient battery charging, affecting the ESS system’s ability to operate.

• Sensor and Wiring Issues: Faulty sensors or damaged wiring can disrupt communication between the ECU and other components, leading to ESS system malfunctions.

• Software Updates: Outdated software may contain bugs that interfere with the ESS system’s operation.

Troubleshooting and Solutions

• Check Battery Voltage: Using a multimeter, ensure that both the main and auxiliary batteries are maintaining sufficient voltage (12.6V or above). Low voltage can indicate a weak or failing battery.

• Inspect Starter Motor: Check for any signs of wear or damage to the starter motor. If the starter motor is struggling to crank the engine, it may need to be replaced.

• Test Alternator: Use a voltmeter to measure the alternator’s output voltage while the engine is running. A faulty alternator will exhibit low voltage output.

• Examine Sensors and Wiring: Inspect sensors and wiring harnesses for any damage or loose connections. Faulty sensors or wiring can disrupt communication with the ECU.

• Update Software: Check if a software update is available for the ESS system. Installing the latest update may resolve any bugs or compatibility issues.

• Replace IBS: If all other components check out, the IBS may be faulty. Replacing the IBS requires professional assistance and reprogramming.

Additional Tips

• Avoid Prolonged Idle: Excessive idling can drain the battery and hamper the ESS system’s operation.

• Drive Regularly: Regular driving allows the alternator to charge the battery and maintains its optimal condition.

• Use High-Quality Batteries: Invest in high-quality batteries with sufficient cold-cranking amps (CCAs) to ensure reliable starting.

• Seek Professional Assistance: If you are unable to troubleshoot and resolve the ESS malfunction on your own, seek professional assistance from a qualified mechanic or authorized Jeep dealership.

Jeep Cherokee Auto Start/Stop Not Working

Why is my Jeep Cherokee’s auto start/stop not working?

There are several reasons why your Jeep Cherokee’s auto start/stop system may not be working, including:

• A weak or failing battery
• Starter motor problems
• Alternator malfunctions
• Sensors and wiring issues
• Software updates

How can I fix my Jeep Cherokee’s auto start/stop system?

To fix your Jeep Cherokee’s auto start/stop system, you will need to identify the specific cause of the problem. This may require a qualified mechanic to inspect the system and diagnose the issue. Once the cause of the problem is identified, you can take appropriate steps to repair or replace the affected components.

Can I drive my Jeep Cherokee with the auto start/stop system not working?

Yes, you can still drive your Jeep Cherokee with the auto start/stop system not working. However, you may notice a decrease in fuel economy and an increase in emissions.