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Interior temperature sensor readings seem VERY low
I've been noticing that the air conditioning takes an increasingly longer amount of time to blow cold air... Today it took almost 10 minute of driving. For reference, it's 85°F outside... So this is completely unacceptable. For a car like this, I would expect cold air to blow before the car even starts driving and air started moving over the evaporator (maybe others can comment on their experience??)
Regardless, it was bad enough that I pulled over and plugged the diagnostic reader into the car to take readings while the system was working, and did a scan of HVAC components. Interestingly enough, the interior temp reading was at 31°F... Almost freezing! Surprising, considering the interior felt more like 75°F.
By now the air coming from the vents was cold, so I pulled the sensor and held it by the vent to see if the temperature changed. Sure enough, it dropped down to 17°F. Turning off the system and using my mouth to blow hot air on it made it raise up to ~30°F. The fan in the sensor is running, and silent. So, it seems the sensor is pulling data, but the numbers are off by about -55°F.
What does everyone make of this? Bad sensor? Do other diagnostic readers show the same numbers, or something more accurate? Do others have cold air instantly, or does it take awhile?
I'm wondering if my reader is just interpreting the sensor data incorrectly and the car is seeing more accurate numbers...
Last edited by TraxtarXKR; Oct 23, 2019 at 05:25 PM.
Interesting post. My 2011 xk also blows a litte too warm air in the first couple of minutes after start in the morning. After highway driving 5 minutes it gets normal, but after another about 15 minutes I tend to find the cabin temp gets a bit too cold and have to push the temp buttons about 1-2 degrees higher. This is the situation in winter. In summer I do only notice the too warm air in the first minutes.
What I also notice, is that the temp sensor on the right behind the steering wheel (behind a little grill, right?) makes a slightly grinding sound before I startup the car. Normal?
How difficult is it to replace the temp sensor? If it was easy and the part wasn’t too pricey, one could just swap it just in case.
I presume that you removed the cover using a plastic trim removal tool. Is there anything to worry about? Seems like that's an easy preventive maintenance task.
I presume that you removed the cover using a plastic trim removal tool. Is there anything to worry about? Seems like that's an easy preventive maintenance task.
Stuart
Stuart,
YES - with the steering wheel moved fully down and towards the driver, the trim is easily prised out from the spring retaining clips with a trim tool. The "tongues" on the reverse of the trim are plastic so take the usual precautions when working with Jaguar plastic!
Maybe a little compressed air would clean that out without necessitating trim removal?
I only dug that far into it because I was expecting a failed sensor. Although either vacuum or compressed air would clean most of it out, the dust does seem to cling to the sensor so I used a fine brush to remove all traces.
Maybe a little compressed air would clean that out without necessitating trim removal?
I thought about that, and was concerned that compressed air would further embed the dust into the sensor and ruin it. Just to be safe, I'm going to vacuum it out while loosening the dust, if necessary, with a small brush.
Are you sure it isn't kicking in? I think cleaning the sensor is a no brainer for all of us after GGG's post/ pic. If you don't have A/C gauges, get a cheap IR thermometer and put in on the lines to see what temps you're getting upon start up and then after a predetermined length of time. Mine is ice cold usually after a minute or so. I'd check the sensor, then go the gauge route personally.
Sensor looks good. It's very clean. No dirt or dust at all. I'll see if I can see the compressor spinning immediately when I start the car, or feel any lines by hand for cold temps.
Are you sure it isn't kicking in? I think cleaning the sensor is a no brainer for all of us after GGG's post/ pic. If you don't have A/C gauges, get a cheap IR thermometer and put in on the lines to see what temps you're getting upon start up and then after a predetermined length of time. Mine is ice cold usually after a minute or so. I'd check the sensor, then go the gauge route personally.
I am sure in the sense that air coming out of the vents for the first few minutes is hot, and that would not be the case if the compressor was running. The system gets very cold eventually.
A theory I have is that it's a pressure-related issue... possibly the low pressure switch is preventing the compressor from kicking on. I'm thinking that heat from the engine eventually causes the system pressure to rise, to the point that it goes above the sensor limit so the low pressure switch enables power to the compressor.
That's just a thought, though. I went out to the car, popped the hood, and obviously I can't see the compressor with all the covers and components in the way... you can barely see a belt spinning! I CAN say that I can manually hit the AC button on the touch screen, and see a change in RPM... which tells me that the compressor is kicking on/off... but the air out the vents is cool at best, and warm/hot at worst. As mentioned, it DOES eventually get very cold. It just takes too long.
It started raining (of course) while I was out there, so parking lot diagnostics are put on hold for now.
I have always been a little disappointed with the air-con in the X150. My old X350 used to go straight to high fan and pump out loads of cold air if I got in it when the interior was hot, even when the engine was cold but both my old and current X150's seem to take a long time to respond and also don't run the fan anywhere near as fast as the X350 used to.
It wouldn't hurt to get the gas level checked though.
It looks like you have sussed out the issue with the iCarSoft readings but as I captured my metrics on the way to work this morning I might as well post them for comparison.
Thank you for submitting your data! More data like this gives a sample pool to compare values to. This is good stuff, people!
Interesting to note, my external CO2 and NOx sensors don't say anything in my iCarSoft module.
Here is the data you posted back when you got your Autel Module in May 2018. Found by searching "Jaguar External Nitrogen Oxide Sensor" in google. Your thread with attached PDF files was the only search result in all of google, strangely enough.
As a second though... I have had the console out a few times doing the GVIF modification. I noticed there were a few codes related to the center stack due to plugging/unplugging the components during my troubleshooting. I will clear them, and maybe that will fix the issue. Will report back with results.
That's just a thought, though. I went out to the car, popped the hood, and obviously I can't see the compressor with all the covers and components in the way... you can barely see a belt spinning! I CAN say that I can manually hit the AC button on the touch screen, and see a change in RPM... which tells me that the compressor is kicking on/off... but the air out the vents is cool at best, and warm/hot at worst. As mentioned, it DOES eventually get very cold. It just takes too long.
Got it, yeah the compressor is clutchess anyway so even if you could see it, there's nothing to indicate it's engaged other than as you note, the RPM's adjust.
Can someone please give me a hint on how to remove the trim panel covering the cabin temperature sensor. I have tried today a bit just my hands, but had no chance to get the panel off.
Interior temperature sensor readings seem VERY low
