Thank you to all on this forum. Hours spent searching posts before I bought my 07 Coupe. In love with the ride - 67k on the clock and rides great with a new set of tires.

I searched specifically on here for this issue to no avail. The dealer tested the battery and said it was good. 14.1-14.4 right after I crank it. It's dropped as low as 12.9 with accessories running after shut down? Getting repeating code P0852 - neutral safety switch voltage. Anyone have any thoughts or run into this one?

first time I drove it there was a siren like sound coming from under gearbox/center console. Went away in park and has not come back. Additionally the adaptive cruise won't engage 99% of the time - no fault codes or cruise not available warnings.

I really appreciate your responses and see why these cars are so loved. I grew up in a 71XKE V12 Silver / Black coupe so I found this one as an homage to my Dad.

 

Here's an article on the error code https://www.engine-codes.com/p0852.html

 

Thank you for the link. I came across that explanation of the code on a google search- best one I found. I was curious if any other owners had experienced a similar situation. I've read a bunch about the no cruise available warnings etc but couldn't find anything on it simply not engaging. I figure the computer is not allowing it due to the 0852 Code. I have an appointment scheduled again at the dealer next week so we shall see what they find.

Unfortunately I'm the type of owner that relies on the mechanics for everything. I've tried things in the past and always seem to do more harm than good with my wrenching skills.

thanks again for your reply.

 

I suspect that you have a weak battery even though it tested OK. Our cars are very sensitive to a weak battery, which causes a wide variety of electrical glitches. That's why many Forum members keep their X150 on a smart battery maintainer (not a trickle charger), particularly if it's not driven every day. The CTEK brand is recommended by many Forum members and is what Jaguar dealers use on cars in their showrooms.

Test the battery voltage in the morning, after the car has sat overnight, and before you start the engine. See:
https://www.jaguarforums.com/forum/x...adings-113258/

 

Full battery charge is 12.6 volts resting. Check her in the AM before starting as Stuart suggests. Start there and let us know the result. If it's less than 12.6 in the AM, order a new battery, have it fully charged by the auto parts store the day before you go in, they'll charge it and drop it in free of an extra charge. Eliminate the power source first.

 

Interstate has franchise stores for batteries and consider an AGM style battery. CTEK is a mandate for any niche car IMO.

 

Will do. And thank you for taking time to respond.

 

On the FM transmitter in the cigar port it read 12.3 / 12.2 upon unlocking this am. So I assume this points to a less than ideal battery.

i will be driving the car 4-6 hrs on highway 2-4 times a month, other trips 5-10 miles around town 3-4 times a week.

would you guys recommend the AGM style battery for this type of driving?

thank you

 

You will find 2 schools of thought.
Some will say AGM, only. But AGM has particular charging/discharging characteristics.
Others will state select the appropriate battery matched to the type of alternator = typically exchange like for like OR as per spec.

I can tell you this from experience: I chose the path of like for like. I do not use a battery maintainer. I have replaced the battery twice. And even though she parks for weeks on end, then may go for a stroll of about 250 miles, she is dependable.

Roll the dice.

P.S. Nice Ride! Welcome to the club of those who know.

 

Thank you. All that was available was a like for like, but for $160 It's OK to replace again if I have to. I think I replaced a good battery anyway, but I see it as insurance. My P0852 is still recurring and the cruise is inactive. So the search continues.

 

Your battery is weak and you should replace it. You can replace your battery with a conventional wet-cell battery having the same or higher CCA rating as the OEM battery it came with from the factory. Also buy a CTEK MUS4.3 battery maintainer from Amazon.

You don't need an AGM battery. Although it will work and last longer, your alternator isn't designed for AGM. However, if you use the CTEK MUS4.3 regularly, it will keep your AGM fully charged.

Compare battery prices at Pep Boys. They installed the Bosch AGM battery in my 2013 XJ and I'm pleased with it. I keep it on a CTEK MUS4.3 .

 

As already suggested by the clan, there are a couple of options to this.
personally, if the park/neutral switch is problematic... I would not want to be stuck somewhere with the car unable to move.
Don’t make an appointment but barge into the dealer service department now, plead despair and get it corrected.

 

A lot of branded car conditioners (BMW, Aston, etc) are just CTEK's with a sticker and different packaging. There are some external quick charge connections available that secure right next to the license plate lights. I see Aston (and Ferrari) doing this on their new models and believe this can be added to any car. Has a magnetic connection so if you forgot and drove off with it connected; it wouldn't damage your car. Been meaning to ask the dealership if this can be added to any car.

 

For best price I always go to Wall Mart; they are all made by Johnson Controls! And yes I use Ctec on both our Jags.....................hope this helps.

Adrian '07 XK Coupe

 

Advance auto was running a 25% off coupon, after the core I was out the door for $138. Happy camper but didn't fix my issues. Also had a engine temp P0016 pop up. Thermostat you think? I know the battery is not causing the codes because it's brand new. And I'm thinking my cutting power and backfire type experience over 4K may be related to the neutral safety switch issue. Very strange because it's responsive and butter smooth up to 4K in regular driving.

 

Fine, I'll say it this time......

A new battery is NOT fully charged. They get manufactured, shipped, then sit on a shelf for months. All "new" batteries should be charged after purchased with a GOOD actual Charger of 10+ amps, preferably for 24 hours.

 

This is absolutely correct....Last year I had to buy a new battery for a 2007 XK (battery at the end of its 8-year life, always on the CTEK unit, but started to give random warning lights, one of them being the TPMS light...and then at a fuel stop, the starter did not engage...and 5 minutes later it did and the car ran fine. Time for a new battery). So, knowing in advance both the answer I would be given and the real answer, I asked the shop clerk as a matter of form if the battery I was buying was fully charged. He said it was, and attempted to prove it by connecting a hand-held unit that they use for this purpose. The read-out said the battery condition was "good". Yup.... of course it wasn't because they never are...so I took the battery home and connected it before installation to the CTEK unit. It took more than 30 hours before it was fully charged. Then, and only then, did I install it. There have been zero electrical issues, nor issues of any kind since then on this beautiful car.

 

On the subject of CTEKs, I recently had to replace my MUS4.3 and found it had been discontinued. It has been replaced by the upgraded/improved and less costly MXS5.0.

 

The MUS4.3 has not been discontinued and is available on Amazon. It's a newer model with more features and costs more than the previous version MUS4.3. As jahummer pointed out, the MXS5.0 is less expensive and may suit your needs. Compare them and decide.

 

Sorry, I suppose I should have clarified both the original MUS4.3 and MUS4.3 Test & Charge ARE discontinued per CTEK https://www.ctek.com/products?page=2, respectively they were replaced by the MXS5.0 and MXS5.0 Test & Charge both with improved features and charging.