cars news 10: 2017 Jaguar F-Pace Long-Term Update 5: Auto Stop/Start/Restart Part 1

Recently, our F-Pace’s auto stop/start system started to completely ignore the second half of its mission; instead of shutting then engine off and starting it right back up again, the car would completely shut down—often at the most inopportune moments (in stop-and-go traffic, left-hand turn lanes, etc.). I first noticed it but thought I might be imagining things. Then photographer Robin Trajano and associate online editor Collin Woodard had it happen to them. Finally, while driving back from a Target run, I got it all sorted.

First a primer for those who haven’t experienced the joys of these fuel-saving ignition-cutting systems. Auto stop/start systems shut the engine off when a vehicle is at rest. The transmission does not need to be in park; all that is required is that the vehicle is stopped with the driver’s foot firmly on the brake in the right conditions. Well, in the case of Jaguar, the auto stop/start system must be engaged (duh), the battery must be fully charged, and operating temperatures must be between approximately 32 and 104 degrees. Furthermore, engine-driven accessories such as the climate control system must be running at little to no load. If these conditions are in place and the engine shuts off when the brake is applied, releasing the brake pedal should spring the engine back to life in an instant so that the car is ready to go.

Except when it doesn’t. On several occasions, our F-Pace would shut down per the normal auto stop/start procedure but fail to restart. In fact, the car would be completely off, with the instrument cluster dark, the transmission in park (instead of drive), and the rotary transmission dial sunk into the center console. Only several, often frantic, presses of the ignition button would start the car back up.

Complicating the troubleshooting process was Jaguar’s convenience feature called Driver Exit mode, which is an extension of the auto stop/start system. With the auto stop/start system on, when you bring your F-Pace to a stop (and the engine shuts off) and pop the driver seat belt release, the vehicle reads this as a parking situation so for safety’s sake will fully shut the vehicle down. It took careful observation to determine that our auto stop/never restart issue was a real issue and not just an unintended Driver Exit.

The first clue was that after the vehicle shut down inappropriately, it took more than one ignition press to start it back up. And once restarted, the auto stop/start system was not available, as shown by an error code in the instrument cluster. Only after cycling the ignition again would the system return to normal—except now that auto stop/start was available, the system could fail yet again.

While on that Target run, I managed to figure out the weird missing link: additional pressure on the brake pedal. While at a stoplight under optimal auto stop/start conditions, the F-Pace’s engine shut off as it should. I turned to reach for something next to me, inadvertently putting more pressure on the brake pedal, and then I noticed the car went into complete shut down mode (instrument cluster blinked off, transmission indicator went from drive to park, and the rotary knob sunk into the console). Bingo. I fired the car up again (noting that it took at least two presses of the button to get it running) and pulled to the curb to see if I could replicate the issue with additional brake pressure. I couldn’t, because of the aforementioned error code, but restarted the car and tried again. Aha, part deux.

Confident I was not crazy and could replicate the issue for our local Jaguar dealership technicians, a service appointment was arranged. Perfect timing, too—it was time for the F-Pace’s first oil change. Next update: fresh oil and answers.

2017 Jaguar F-Pace Long-Term Update 5: Auto Stop/Start/Restart Part 1

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