Jeep 2015 Cherokee Engine Start/Stop System Troubleshooting

When I had the dealership service center take a look at the ESS system (the first time it engaged while in Park in a parking space at work), they said it was operating correctly, and kindly gave me some printouts on the ESS system from dealerconnect.Chrysler.com. So basically they were saying to me “user error.”

But now that it has happened a second time, let’s take a look at how Fiat Chrysler designed Jeep’s ESS system, and see how the manufacturer says it is supposed to work. If indeed there is a “user error,” I’ll be the first one to say “my bad.”

[UPDATE:  On July 18, I pulled into a parking space, and with my foot on the brake, before I could shift into park, the engine turned over. The ESS system was turned off, meaning I pushed the button so ESS would not autostop, because it is annoying and interferes with my driving. Since this behavior is intermittent (happened a minimum of half a dozen times), it will be very hard to get a dealer to look and diagnose. They’ll check for “codes,” and they’ll say, “no codes.” And I’ll be ____ ______ again.

If you are having safety problems with your Jeep, please log them at Center for Auto Safety and NHTSA.

I need to do that. If the engine can turnover (maybe it is just an engine rev, I don’t know, but it sounds like a start up, which does not make sense since the car is started and running) at random points, what if it turns off while I’m driving? I have seen some complaints of that happening.]

Following is some of the information from Fiat Chrysler about how ESS is supposed to work (or not work).

To Activate Autostop Mode, the following must occur:

  • The vehicle must be in a STOP/START READY state.
  • The vehicle must be completely stopped.
  • The shifter must be in a forward gear and the brake pedal depressed.

Possible Reasons the Engine Does Not Autostop

  • Driver’s seatbelt is not buckled.
  • Driver’s door is not closed.
  • Battery temperature is too warm or too cold.
    [You need to be more specific.]
  • Battery charge is low.
    [You need to be more specific.]
  • The vehicle is on a steep grade.
    [You need to be more specific.]
  • Cabin heating or cooling is in process and an acceptable cabin temperature has not been achieved.
    [Huh? What is an acceptable cabin temperature? Is it something like between 68 and 72 degrees?]
  • HVAC is set to full defrost mode at a high blower speed.
    [I believe I have experienced this, which I interpret as “inconsistent ESS system behavior.”]
  • Engine has not reached normal operating temperature.
  • The transmission is not in forward gear.
    [FALSE! The ESS system works in Park, as Jeep #4 has demonstrated twice in the first 40 days/1,000 miles.]
  • Hood is open.
  • Vehicle is in 4LO transfer case mode.
  • Brake pedal is not pressed with sufficient pressure.
    [Now this one was helpful to me. I was wondering if I needed to press the brake harder to get the Autostop to work. I think there have been times I have been stopped, but I was not applying enough pressure to the brake pedal, so the engine continued to run. So how much pressure is needed? Because some people who are not bodybuilders with crazy strong legs might have a lighter touch.]

Other factors which can inhibit autostop:

[To me “inhibiting autostop” means the engine will continue to run though you are stopped at a stop light and brake pedal is sufficiently pressed.]

  • Fuel level.
    [That’s vague. More info needed for this to make sense or be valuable information for troubleshooting.]
  • Engine temp too high.
    [How high is too high? In the danger zone, or can it be less than the danger zone?]
  • Accelerator pedal input.
    [Let’s hope so!]
  • 5 MPH threshold not achieved from previous AUTOSTOP.
    [What does this mean?]
  • Steering angle beyond threshold.
    [What is the threshold?]
  • AC is on and speed is set.
    [I’ve noticed that using the fan disrupts the ESS system, and Autostop Mode won’t activate; or if I am stopped and Autostop Mode is Active, meaning the icon is lit, and I turn on the fan, the engine starts]

Conditions that will cause the engine to start automatically while in autostop mode:

  • The transmission selector is moved out of DRIVE.
    [Several times when I am stopped in a parking space, and I shift from DRIVE to PARK, the engine turns over. Why is this happening?]
  • To maintain cabin comfort.
    [Huh? Need more info. Give examples.]
  • HVAC is set to full defrost mode.
    [True.]
  • HVAC system temperature or fan speed is manually adjusted.
    [True.]
  • Battery voltage too low.
  • Low brake vacuum (e.g., after several brake pedal applications).
  • STOP/START OFF switch is pressed.
    [Does this mean pressed with the intention to turn on the engine?]
  • A STOP/START system error occurs.
    [Like what? Are there error codes?]
  • 4WD system is put into 4LO mode.

OK, and so no wonder I have had such an inconsistent experience with the 2015 Jeep Cherokee ESS system. There is no such thing as consistent behavior. Which makes me ask… what is the point? You never know if it is working right!

Conclusion:  If this is the information Chrysler is giving to dealerships to teach them how the car works by design and to help them to troubleshoot and service cars, the consumer should not expect much, such as an explanation as to why the engine starts while the driver’s foot is on the brake pedal and the transmission is in Park. It is not supposed to do that.

MEMO to Fiat Chrysler:  update your documentation on the ESS system. Give real world driving scenarios.

[UPDATE 8/19/15 – It’s for certain. If I do not deactivate the ESS system, when I pull into a parking space, with my foot on the brake, the car shuts down. I then shift into Park, and the engine starts up again, all while I’m reaching to push the Start/Stop button to turn off the car. This is bad design, and also dangerous.]

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One thought on “Jeep 2015 Cherokee Engine Start/Stop System Troubleshooting

  1. Monica December 21, 2016 / 8:47 am

    My start stop system on my 2015 Jeep Cherokee stopped working altogether recently. It is supposed to be on when you start the vehicle and you push the button to turn it off. I can not turn it on or off. Recently had an after market remote start installed and wonder if they disconnected something.

    Like

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