Breezy_Pete

Message me your VIN and which corner of the car needs sensor, and I'll tell you the correct part number. Tell me the complete exact part number of what has been fitted too.

Try the radiator fan test first, very common fault on VW group cars of this age, and will lead to higher temps in the conditions you describe. Any old bit of wire will do for linking, the currents through these connections only power relay coils on A/C equipped cars, not the fans themselves. Note that ignition needs to be on to test full speed function.

Test the radiator fans to ensure that the low speed function is operable. Do this by linking pins of the radiator thermoswitch connector. Pinout details can be provided if non-obvious. Does the car have A/C or not?

First two results here show you what genuine ones of the correct part number look like. Prices seem OK too. 6Q0698151D for sale | eBay

Looks like you do have standard (288) brakes I think, and GSF have duff info in their system.

Cool, GSF part number of what you've been given would be handy too.

You may have non-standard front discs/pads fitted, the car's new to you right?

My mistake, I thought you said discs were wrong size, but I had misread.

What size did they give you?

Well I've said everything I feel is useful here, byeeee.

Might not matter to you, but it does to me. Each to their own but I favour facts over lots of words.

1 and 3 are on the current approved list, 2 isn't.

Did you mean to ask me that? The list I'm referring to is the current 504/507 pdf on erWin, no mention of US that I can see?

Nope, look at the list, loads of 0W30s on it. 🙂

Comma Prolife SAE 5W-30 50400/50700 is on approved list. You only have to create a login on erWin to be able to see all the approved oils, no cost involved. Link on right side of homepage when logged in. As long as your chosen oil meets 504 00 spec it'll be fine no matter what oil change interval, manufacturer or viscosity index.

Rad fan testing by linking radiator thermoswitch connector:

Have you still got the sensor that you pulled out? Had same error on our Fabia very recently, seemed to give OK temp numbers but kept logging that fault, even put the EML on while missus was out and about. Replacement fixed it, and only thing apparent when examining old one was that the junction of brass to grey plastic had gone a bit loose; could twist the two bits relative to each other through a small angle with little effort.

Others that share that splice are G42/G71 IAT/MAP sensor and G40 Cam position sensor.

White wire from pin 1 at sensor connector goes to ECU connector pin 74, brown earth goes via a splice called 'sender earth' in the engine loom to pin 54.

Furnish me with engine code or VIN and I can give you pin numbers at engine ECU tomorrow.

As you have figured out, the temperature sensor is driven/read by the engine ECU, and the results communicated to the cluster only via CAN messages. If I were trying to pin this down I think I would log (with VCDS) coolant temp as reported by engine ECU during some driving, and look for any glitches in the data; or generally implausible numbers. I wouldn't, in fact I think that might be my prime suspect. Do you have pinout info? Any moisture in the connector at engine end? Engine ECU fault really unlikely I think.

Your front brake PR code is 1LG, 340mm discs; rear is 1KT, the 272mm solid 10mm thick discs.

@RossMacGill Chuck me your VIN by private message, I can look up.

Indicated 90 covers a pretty big span of reality, so yes, still possible I would think.

I'm seeing two 12V feeds on pins 18 and 20 of a 20-way connector at passenger front window motor, red/yellow thin one and red/white thick one, respectively. Got both? Measure relative to earth on pin 19 to test earth return intactness.