Citreon relay U1218 communication to bsi, B1029 outside temp sensor.

[@simonparkinson1053]

Nice one Adam. Had this same wild goose chase myself, Citroen only sell the mirror assembly complete with sensor, but you can get the sensors separately from Fiat. PITA to fit into the mirror housing though.

[@acautotech7231]

I couldn’t see it in Mirror so checking all different places info doesn’t say it’s that easy to get to plug Ryan Colley said plug there so nice easy one to remember for future. I believe the mirrors can be got via aftermarket with sensors in now

[@simonparkinson1053]

@@acautotech7231 mine had aftermarket mirror too, same wild goose chase info. Saw that connector and used decade box at 10k to ground and saw change on data so knew I was on the right connector. Then it was the hassle of getting the sensor

[@AbbottAutomotive]

Nice work buddy. 👍🏼

[@Antsummerfield83]

U1218 :81 how do I find what this is I have like 13 of these faults. Today I have broken down. Car sounds horrible like air box so loud and car is restricted, rev the engine and it sounds very rattly. Lucky to get 15mph. Only fault is that but I don’t no what that is 🤯

[@Isleofwightpaulwalker]

Should I replace the sensor and it will fix the problem?

[@terencesibley6216]

Have 2012 ds3 1.6hdi with U1218 and got no fuel supply to injectors. What topdon is it please.

[@peskyparttimers8239]

I have this exact same problem, sensor is missing and I have an error code for it. Can you remember what the resistance rating was in the decade box and which 2 pins in the 4 pin plug you connected to? I just want to connect a resistor across it as a temporary fix till I can get hold of the thermistor sensor . If I can fool it into thinking its +10 rather than -40 that'll do for now. I have some aircon and general running issues and as this is the only fault code I havn't cleared I'm hoping this will sort it.

[@acautotech7231]

I can’t sorry if you pause video and zoom in you might be able to work out what it is. I believe sensors available seperate on internet. And it’s two pins from grey plug

[@peskyparttimers8239]

@@acautotech7231 Sorted it in the end, got the wiring diagram from Fiat ELearn and connected a 10k pot across the grey/red and grey/green. I can set it to whatever the outside temp is more or less and the last and final fault code is gone at last. It'll do till I can get hold of a mirror👍

[@bradlock76]

Wow by a stroke of luck ive just found this video...I have a 2020 Citroen Relay, I've noticed that the wing mirrors were replaced in the paperwork history a while ago, probably after market. My outside temperature gauge doesnt seem to be working, & the engine fan seems to be working a lot at high speeds which seems a bit lould, cuts out though when I gnition is turned off, coolant levels etc are fine..is it possible that this might be my problem.? Many thanks for posting.

[@acautotech7231]

It’s entirely possible as ad blue models heavily rely on outside temp or can cause lot of issues

[@bradlock76]

@@acautotech7231 Man it was exactly that, after seeing your first post, I had another look at my mirrors & at the drivers side, the temp sensor was missing (after market mirrors with no sensor) my engine fan had been running like a harrier jump jet.. So I bought an after market wing mirror (with temp sensor). Problem now gone 🤞. So for sure this is one to look out for folks. Thanks again bud 👍