Took my 2010 xkr to an indy shop to have my brake fluid replaced. Before I left they said "hey it seems that your car isn't recognizing the key fob". I thought oh well because that happens from time to time and might need to replace the battery. However, I drove the car home and now it will not start at all. It 100% recognizes the key fob but nothing happens when I depress the brake pedal and push start. Everything else comes on, radio, air, lights etc. Is there anything they could have done to mess something up that would prevent the car from starting?

 

Charge your car battery fully, then please report back.

 

They battery is just a couple years old. I don't have a way of checking the voltage but I hooked up my heavy duty jumper and nothing. Everything comes on, its not even clicking at all. Also, the emergency brake wont disengage either.

 

I just recently fitted I new battery in October as of last month it was faulty and I claimed a new one on warranty.

The point is a battery can become faulty after anytime and a couple of years is all it can take .

Get yourself a multimeter and you'll be able to test voltage

 

Got it. I have free road side coming to check it out. Will report back.

 

Typically, roadside assistance merely provides a jump, to start the car.
These cars are electronically sensitive. And even while running, a poor battery will cause all sorts of unrelated issues.

The battery needs to be load tested. Voltage alone is only part of the issue. The battery capacity (amperage) needs to be confirmed.

Also, think of the car’s alternator as a “maintainer”. And not as a “charger”.

 

That's way too much of a co-incidence happening immediately after a fluid flush. I suspect it's not recognising the depressed brake pedal signal to the ECU rather than an issue with the remote.

Graham

 

If they cant test it, will that work? Forgive my ignorance.

 

May I propose you give a read first: https://batterystory.com/how-many-am...-volt-battery/

Then choose the multimeter.

 

The "depress brake" signal turns off after I depress the brake.

 

It's a busy night with battery issues, lol. Graham has “stickies” at the top of this forum. May I suggest you have a look at the “Battery and Charging System - General Information - Battery Care Requirements” in the workshop manual. It is interesting.

I’m throwing the dice that during the brake fluid flush service, the battery was drained. The jury is still out if the battery can take a full charge.

 

Roadside came. Voltage on the battery was fine. Disconnected the battery then reconnected and it fired up. I assume the indy shop did the same thing to get it going again. What could the issue be?

 

The MESSAGE could disappear from display in the Message Centre but that's not a guarantee the SIGNAL is passed to the ECU. An alternative starting technique for this is to press and hold the Start button and then press the brake pedal hard to initiate engine start.


A battery disconnect/reconnent is known as a 'hard reset'. This resets learned adaptions (fuel trims, window travel limits etc) to factory defaults by discharging on-board capacitors. It doesn't clear DTC's (fault codes) but it does set the security system to the same state as it was before the disconnect.

Always eliminate a partly discharged or failing battery first when experiencing weird electrical faults on these vehicles. My second step is then to hook up diagnostics and search for relevant codes. Also, are you trying to start it with the smartkey on your person or docked in the console?

Graham

 

The battery is 100% fine. When it wasn't starting it was still recognizing the key but I tried docking it as well and it still didn't start. It looks like the disconnect and reconnect of the battery solved whatever the issue was. She fired up with no issues this morning. I have no clue what's going on with this car sometimes.

 

You can continue to speculate or run a diagostics (SDD) session for more logical troubleshooting.

Graham