Interesting - a third variation.

The one on the right is the original Impact Sensor from my 2007 XK. The one on the left is the current version which supersedes it.



Apparently this current version is less prone to false errors. Downside is it has only one fixing hole and this has to be drilled in a new location. There's a TSB on the procedure.

Graham

 

And the warning is back on.....

And now it has gone again!

It seems that each journey I make in the car may or may not cause the warning to display. If it does, it is when the engine is started and it stays on for the duration.

Jima, thanks for the feedback on cleaning the contacts. I was going to have a go myself this weekend, but it would appear that isn't going to resolve it and replacement sensors is the only option. I'll have it checked during my up-coming 120K service and hopefully the mechanic will be able to source some second hand parts if they are required.

 

I don't know any reasons why they do fail, just that it seems quite common, I too was optimistic that it was a false alarm or just something that happened when very hot (so it wouldn't matter to us in the UK) but it became increasingly regular and I like my cars to be perfect so I had to get it sorted. Apparently the new sensor is less prone to failure although that is what failed on mine (2012 car, I'm not sure what year the new sensor was introduced) it was roughly a year ago so it only lasted about 6 years.

 

As a test is there a way to jumper out this sensor .

 

A failed sensor will record an 'event' when you start the vehicle and illuminate the warning light. An erratic sensor will not necessarily do this on every start.

Once the number of recorded 'events' hits the limit (I think this is 100), the warning lamp will stay ON whenever the engine is running.

You need Jaguar SDD to read the extended codes indicating left or right sensor fault and the number/timing of recorded events.

When I purchased a replacement sensor in November 2017, the retail was £76.80 plus VAT but Stratstone Jaguar discounted it to £53.76

Once the sensor was replaced, the code cleared from the permanent list and the warning light stayed OFF.

Graham

 

Just exactly How Many XKs have run into pedestrians and had the pedestrian wonk themselves silly on a solid bonnet?
I say, disable the silly tripe!

 

Wish you could!:-)

 

It seems that modern cars have far too many sensors with a limited lifespan and it is the sensors that are the problem rather than the parts they are supposed to be protecting!

One example of this is the pre-oxygen sensor (lambda sensor) that supposedly protects the catalytic converter. I've now lost count of how many of these have been replaced on our family cars. They are clearly not fit for purpose.

 

That is NOT AN OPTION in the UK. The system was developed and fitted to enable the low front end of the XK (and other Jaguar models) to obtain European Type Approval. Without that certification, a vehicle cannot be used on the roads.

Every UK insurance policy I've read includes the caveat that any modifications from original specification must be declared or a claim is likely to be rejected. Disabling an OE safety system goes well beyond modification.

A driver who hits a pedestrian in this country is almost always judged guilty. If a pedestrian is injured and the PPS fails to deploy because the driver has deliberately disabled it, the criminal charges and uninsured liability could be staggering.

Graham

 

You may find that this is in the nature of the lambda sensor chemistry/physics. Filament light bulbs will eventually burn out due to their physics, it is not a conspiracy by the manufacturers.

Anyhoo, my $20 impact sensor turned up yesterday and has now been fitted so we will see what effect it has. The old one has run for several days without error before so it will take a while to be sure but I will report back.

 

Happy to report over a week now and no DTC's (touches wood). Oh! I didn't have to remove the nose-cone either as has been suggested by some even though it is an S/C model.

 

James,

The DTC and warning disappeared on mine as soon as the sensor was replaced and never returned.

Although I could see the sensor from below, I didn't have sufficient room (or perhaps an appropriate drill) to mark and drill the new hole for fixing the single bolt current design sensor in place of the original 2 bolt sensor. (see post #21).

I therefore removed the front bumper. How did you do it?

Graham

 

Ah! I see why you might have had to do that. I was lazy - I made sure I bought a two-hole sensor.

 

Just a final report to close off - still no impact system DTC's. Disclaimer: a $20 sensor off a wreck is a bit of a gamble and it may only have a partial life left but if you choose carefully and avoid front-enders you may get a few (or more) trouble-free years.

 

My 2004 XKR had its 130K service yesterday and the pedestrian system sensors were "recalibrated" and didn't come on after that.

However, today, the warning is back so I'm booking it in for 2 new sensors.

 

2004?

The Pedestrian Impact System wasn't introduced until 2006 - nor was the XK.

Graham

 

Your right, I meant to type 2007, not 2004, which is when we got our old, failing BMW X5!

 

The new sensor does not need drilling, the fixing hole from the old sensor fits if you angle the sensor around 35-45 degrees. I don't believe the angle has any impact on the sensors function or am I wrong?

 

My Pedestrian warning is showing randomly now, so I think it's time to change the sensors.
Are there any videos or written instructions showing how/where to find these sensors and how to go about replacing them?
I assume after replacing, nothing needs to be reset? The warning seems to come and go, so it isn't a case of once it has appeared it always appears until switched off.
Thanks.

 

I looked at that option and found the new pattern sensor could be fitted to one of the existing holes at an angle. However, there had to be a reason for the TSB being so precise about positioning that I decided to follow it.

I'm sure you are correct that the sensor will function at any angle of rotation and can only surmise the recommendation is either to avoid stressing the harness or making the connector vulnerable to damage.

Graham