Press brake pedal then button, doesn't start
#1
12-14-2014 | 05:07 AM
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From: Ireland
Press brake pedal then button, doesn't start
Just want to see has anyone this issue and the cause:
I have this thing going on with my xkr since i got it, and it has a new agm Bosch battery. Sometimes when i go to start it , pressing hard on pedal first then press button it just makes a click noise and i have to repeat the start process again, then it goes. Doing the process the other way round of Pressing button then pedal has no effect still does it sometimes, and battery fully charged, any ideas anyone.
On a message fellow member sov211 said;
This starting activation issue is very common - a minor annoyance, but an annoyance. It happens to me about once in every 10 starts.
As you press the button, look at the gauge unit in front of you: the central display section must be active. Frequently one push of the button will activate that display and then it will go out - no start! The second push of the button will generally activate and maintain the display and pushing the brake pedal will start the engine. I have had no satisfactory explanation for why this happens, but as I said, it is very common. It seems to make no difference whether you push the START button fist or the brake pedal first. This is NOT related to battery voltage so this interesting issue is really for another thread but I'd be very interested in hearing if anyone has had an explanation of why this happens. It could be a software issue of some sort, I would guess.
Any answers from anyone, it doesn't bother me but is it a matter of getting used to it.
I have this thing going on with my xkr since i got it, and it has a new agm Bosch battery. Sometimes when i go to start it , pressing hard on pedal first then press button it just makes a click noise and i have to repeat the start process again, then it goes. Doing the process the other way round of Pressing button then pedal has no effect still does it sometimes, and battery fully charged, any ideas anyone.
On a message fellow member sov211 said;
This starting activation issue is very common - a minor annoyance, but an annoyance. It happens to me about once in every 10 starts.
As you press the button, look at the gauge unit in front of you: the central display section must be active. Frequently one push of the button will activate that display and then it will go out - no start! The second push of the button will generally activate and maintain the display and pushing the brake pedal will start the engine. I have had no satisfactory explanation for why this happens, but as I said, it is very common. It seems to make no difference whether you push the START button fist or the brake pedal first. This is NOT related to battery voltage so this interesting issue is really for another thread but I'd be very interested in hearing if anyone has had an explanation of why this happens. It could be a software issue of some sort, I would guess.
Any answers from anyone, it doesn't bother me but is it a matter of getting used to it.
#2
12-14-2014 | 12:32 PM
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From: Pacific Northwest
I had this for some time, and struggled to prove it to the dealership as it was intermittent. My engine would always light on the second try, so it was an annoyance but not critical.
Finally it happened at the dealership and they detected a key fob error. Replaced both my keys and the problem went away...
Never thought about the fobs as it happened with both of them, but the problem has not returned since...
Finally it happened at the dealership and they detected a key fob error. Replaced both my keys and the problem went away...
Never thought about the fobs as it happened with both of them, but the problem has not returned since...
Last edited by CleverName; 12-14-2014 at 12:35 PM.
#3
12-14-2014 | 01:47 PM
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From: London, UK
As I posted elsewhere, there are a shedload of conditions that have to be met before the car will start:
(N.B. this is for the 5.0, but I believe the 4.2 is similar)
I know that, in one case, failure to crank was caused by air in the brake lines, which meant that the brake pressure didn't meet the threshold. But it could be a glitch in any of the other checks.
The engine starting process is initiated when the start/stop switch and the brake pedal are pressed simultaneously. The engine management system will only allow the engine crank, fuel and ignition functions when the following conditions are met:
- A hardwired P (park)/N (neutral) signal is received from the TCM (transmission control module)
- A hardwired ignition signal is received from the CJB
- A hardwired crank request signal is received from the CJB
- An encrypted data exchange between the instrument cluster and the ECM is verified.
- Exchange encrypted data with the keyless vehicle module to validate the smart key
- Exchange encrypted data with the instrument cluster to authorize the ignition status.
- Brake pressure signal from the ABS (anti-lock brake system) module, which must be greater than a pre-determined threshold
- Hardwired transmission in P signal from the JaguarDrive selector.
I know that, in one case, failure to crank was caused by air in the brake lines, which meant that the brake pressure didn't meet the threshold. But it could be a glitch in any of the other checks.
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#4
07-26-2022 | 08:24 PM
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Joined: May 2018
Posts: 2
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From: 2832 Hillstone
Jaguar XJL Portfolio 2015
Thank You, You are my HERO for today, Issue was passager side break line rupture while backing out of my garage pressing break pedal suddenly loss all pressure,
googling internet for to day, trying to say correct wording to hit the correct answer, it worked found your thread, printed out went to the car did exactly as it was written
& wallah it WORKED! THANK YOU!
googling internet for to day, trying to say correct wording to hit the correct answer, it worked found your thread, printed out went to the car did exactly as it was written
& wallah it WORKED! THANK YOU!
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