“Stop Start Unavailable, Service Stop Start System” in Jeep – What to Do?

Your Jeep's start-stop function is an automated system that ensures your engine does not spend too much idling. It starts or stops your Jeep's engine depending on the driving conditions. For example, auto stop start will prevent your engine from running when you stop at a red light and start once the coast is clear. The system helps reduce fuel consumption and the generation of exhaust gases. At times, it also comes in handy to prevent accidental collisions.

Stop start unavailable, service stop start system message highlights

• Common reasons:aux battery is dead, main battery is dying
• How to fix:check and charge the batteries, replace the faulty battery
• Possible consequences:if the batteries are dead, you may get stranded easily
• Priority level:Medium
• Can you drive?Yes
• DIY repair:Possible
• Repair price range:$200-$700

What to Do When Your Stop-Start Function is Unavailable

Do not fret when the warning light begins blinking because your car is still operable. It is only advisable to drive the car as long as you must because the stop-start system is an environmental and economic feature. Ignoring the warning puts your wallet and the environment at significant risk.

Your Jeep will consume more fuel and produce more exhaust gases should the start-stop system fail to increase efficiency. Failure to address the problem will cost you more at the gas pump, reduce your safety, and increases your chances of getting into trouble.

All diligent drivers should try to get to the bottom of the Jeep's auto stop-start unavailability as soon as they detect the problem. You can take your car to the Jeep dealership or a reputable auto repair shop for accurate diagnosis and efficient repairs.

Why is Your Jeep's Auto Start System Unavailable?

Your Jeep's auto stop-start system is automatic. It is controlled by the car's electronic control unit that relies on data from various sensors. When the ECU detects that your car has reached a standstill, it should shut off the engine.

If the ECU detects that some of the parameters necessary for the auto stop-start function to kick in are not within the range allowed, it will display the unavailable warning sign instead. These parameters include:

• Battery health
• Engine temperature
• Internal humidity and temperature
• Braking force

Should your ECU detect that any of these elements are not operating optimally, your Jeep will warn you that the stop-start function is unavailable.

Here are the most common causes of the unavailability of the auto start-stop system in your Jeep:

1. Your Jeep's Main or Auxiliary Battery is Past Its Prime

The most common cause of stop-start unavailability in Jeeps is the failure of the auxiliary battery. Start-stop systems require more current than your conventional SLI battery can provide. Since your car starts and stops numerous times in a single journey, the auxiliary battery must be designed to handle continuous charge output, i.e., charging and discharging several times during each journey.

Cars without the start-stop technology only start at the beginning of the drive. The generator feeds your electrical components, which prevents the battery from discharging. On the other hand, your Jeep's battery experience several stop periods during which your electrical components continue to draw power from the battery-the continuous charging and discharging increase the load.

Stop-start batteries have technology that lowers their resistance to allow charge acceptance during short drives with several stop-start phases. They also have a longer shelf life than traditional starter batteries. Unfortunately, the battery cannot last forever.

The older your battery is, the more likely you will have challenges with your stop-start system. You are most likely to encounter the stop-start unavailability problem during short journeys or in the winter. A gradual discharge of the battery will eventually cause the ECU to detect the malfunction, thus taking the stop-start option off the table.

Solutions:

If either of your batteries fails, you will have to replace them. Be careful because some Jeep drivers have reported only experiencing the stop-start problem after installing a new battery. Ensure you get a battery that is compatible with your vehicle. The best way to guarantee this is by having the replacement done at the dealership. Alternatively, you can rely on a trustworthy auto repair shop with licensed Jeep mechanics.

How to Replace Your Auxiliary Battery?

If you are an avid DIYer, you can consult your owner's manual to order a compatible replacement online or at an auto-parts. You can rent the tools needed at your local auto parts store if you do not have a healthy toolbox.

• Locate the battery - it may be placed in different location according to the model of your Jeep.
• Use a 13mm wrench to disconnect your auxiliaries battery's negative side
• Use a 10mm wrench to disconnect your main battery's negative side.
• Use a 13mm wrench to disconnect your auxiliary battery's positive side
• At the top of your auxiliary battery, disconnect your vent hose from the two connected points.
• Unbolt the nuts on the retaining
• Remove the retaining strap to free your auxiliary battery
• Remove your auxiliary battery
• Reinstalling the new battery by reversing the uninstallation process described.

2. Your Jeep Has Electrical Issues, e.g., Corrosion at Terminals or Bad Ground Connection.

A bad ground connection often causes the stop-start unavailable warning because, over time, it begins to arc and eventually welds the connector and the nut. You should inspect all your battery terminals for signs of corrosion. Additionally, ensure that all the connecting wires are firmly attached.

Solution:

If your Jeep only suffers a loose wire, calling the professionals may be overkill. All you need to do is secure it firmly and observe if the warning light disappears. Some electrical problems like poor ground connection and corrosion are best left to professionals. Licensed mechanics will test your battery, cables, and connectors to ensure all are in excellent condition.

3. It's Freezing Cold or Melting Hot Outside

Like you, your stop-start function is not crazy about working in terrible weather conditions. Extreme temperatures considerably strain the stop-start function because the air conditioning unit will likely run longer than usual. Most battery management systems deactivate the stop-start function if your cabin temperatures deviate beyond the 40F - 85F range.

Your AC is the most power-hungry component in your car. Running the AC for long periods will likely push a battery with average health over the edge and cause your battery management system to detect a problem. In turn, the ECU will inactivate your stop-start to prevent putting too much strain on your battery.

Solution:

Your Jeep should be able to sustain the stop-start system while your AC is running. Even with components like lights and radio running, your minimum battery voltage should still be sufficient for the optimal operation of your sop-start system. If the AC causes start-stop unavailability, you are likely overdue for a main or auxiliary battery replacement.

4. Your Jeep Has Engine Problems

The stop-start function is linked to your battery and engine. Any malfunction in these components is bound to cause stop-start unavailability in your Jeep. The ominous check engine light often accompanies the stop-start problem warning. Low or high engine temperatures are the most likely to trigger the failure of your Jeep's stop-start function.

If your Jeep often overheats, your radiator fan will draw a lot of current from the battery. The increased load will trigger the unavailability of your stop-start system. Likewise, if your battery is too cold when starting, it will need a larger current to generate heat through combustion.

Solution:

Drivers whose stop-start warning is accompanied by a check engine light should schedule an appointment at the dealership as soon as possible. While no problem gets better on its own, engine trouble gets dramatically worse and costlier the longer you ignore it. Avoid having engine work done by unlicensed professionals as cheap is often dear.

5. Your Jeep's Conditions are Unsuitable for Stop-Start

Many factors outside of battery health, electrical problems, and an extreme climate can cause your stop-start to be unavailable. Most drivers need to be in the know about these conditions.

Did you know that your stop-start will be unavailable if:

• Your hood or doors are open or improperly closed
• Safety belts are not worn
• Your parking assistant is activated
• You are driving up a steep hill
• Your wheels are turned at a sharp angle
• You deactivated the stop-start but forgot to reactivate it.

Solution:

Once the conditions highlighted are no longer a factor, your Jeep's stop-start system will be right as rain. Wear your safety belt or close the door to watch the light disappear.

When your Jeep's start-stop function is unavailable, you should take it to the dealership to avoid any surprises down the road.