Tesla Model S Thermal Controller (#P52F1)
Aaaanother Tesla blog entry, yawn…
This is a follow-up to #P52, the grounding stud issue of the legacy Model S. Technically, as of yesterday, all Model S are legacy cars, Tesla axed both S and X and just sells off remaining inventory. Sad to see it go…
So, with the power issue resolved, this THC_w0105 coolant low warning still showed up basically immediately and never really went away. The coolant reservoir is still filled to spec, so nothing is leaking, but the sensor reading is garbage. I visited the Heilbronn service center, and they confirmed that the sensor upon power cycling just reads garbage, but they didn’t have one in stock. So after a (surprisingly low) 50.63€ diagnostics fee, I went back home and they scheduled a ranger appointment instead. SeC Heilbronn also didn’t manage to correctly send my battery serial number over to the mothership, so my MS still feels…85D’y.
Anyway, with the ranger appointment vanishing after a good week, shortly before the actual appointment date, I didn’t really care if someone showed up, but in the end it worked out reasonably well (meetings + weather, but that’s a different story). Apparently, the sensor is fine after a quick replacement (a 5€ jobby, but difficult to insert without draining the reservoir…on our parking lot), but the controller port is the culprit.
Aaaand since the guy did come prepared, I ended up shelling out quite a few bucks more than just the fiver for a sensor. Well, that’s the life of a now-vintage car owner. But I got to keep the box – and the old controller. And the issue is resolved!
Fancy box of the new controller:
Fancy old 1034215-00-A Rev 01 controller 
Very simple construction and located on the inside of the car, so minimal weather-proofing of the box, but still conformally coated inside (see below). Strange to see an LG logo on the case…do they make a lot of car components? I didn’t know that…
Opening is dead simple, just two latches on each side. Not glued, not sealed, no tools required.
I did have a short brainfart moment where I wondered why the new controller is made in 11/2014, are they still selling off new old stock because they ordered too many? Then it dawned on me: That’s my OLD controller, and my car was made in summer of 2015, a November ’14 part is perfectly reasonable to have if it never failed. The NEW one is of course in my car…d’oh, I’m such a dumbfuck sometimes.
Simple construction also on the inside. Conformally coated (a little bubbly sometimes), PCB marked Fab 1006014-00-B REV 01 JJB-SEP2010 (well within the development phase, the first ones were built in 2013), four identical but color-coded “Stac64” automotive connectors from Molex, 34691-200 22214-4 (black), 34691-0201 22314-4 (gray), 34691-0202 20914-2 (brown) and 34691-0203 05214-2 (green), and lots of passive components on the back (three diode packages, D26, D27 and D45).
On the front, there’s the main Freescale (part of NXP since 2015!) MC9S12XEQ384MAG 1M12S XQAC1435C controller, which is a “16-bit MCU, S12X core, 384KB Flash, 50MHz, -40/+125degC, QFP 144” that is still in active production, plus some more Freescale parts. There’s two MC33972TEW CTDA1436B (“Switch Detection Interface, 22-switches with Suppressed Wakeup, 3.3 V / 5.0 V SPI , SOIC 32”) that are “in development”, so they never fully went through qualification phase and are probably hard to get, and another MC33742PEG UCTLD1441E (“System Basis Chip, CAN, 2x 5.0V/200mA LDOs, 4 wake ups, 15 ms reset duration, SOIC 28”), also still in production. The two large chips on the side of the black connector are ST VNQ5E160K 990LYV6 442 (gosh, that’s difficult to read), which are “Quad channel high side driver for automotive applications”, that checks out.
Well, I don’t see any obvious defect, so unless I fancy swapping the unit back into the car again and see if it was indeed not a sensor error, I think I’m going to keep it in the misc car parts bin and forget about it. They aren’t selling for all that much money on eBay in working condition, and I shouldn’t have looked, now I’m miffed about the new part (although the on-premise ranger service was nice and anything else would have cost me an entire day, maybe even two, to get there). Well, again, that’s what you get with an old car while not being a mechanic. If it doesn’t fit on my desk, I’m having a hard time really digging into it. And unfortunately…I don’t own a car-sized desk. Yet.
No car-related stuff in the next post, I promise…
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