Faulty External Temperature Reading.

[petethegreek]

Does anybody have any idea why the external temperature reading of my Highline 150 would be fluctuating between 18 degree and minus 42.5. Its only just started happening over the last week.
I had it in for some warranty work after engine management light came on and they replaced the EGR coolant pump.
Would this have any effect on anything else?
Thanks.

 

[petethegreek]

Also just realised the air con won’t work, I’m thinking this is to do with gauge showing -2.

 

[Pauly]

It’s strange to see a weird reading, if you unplug the sensor it shows no temp display so the fact it’s reading so far out shows it must be getting some signal back
The sensor is located behind the front grill if you bend down and look up through the slats you can see it, I think (and it’s only think) that if you open the bonnet and take out the four plastic fixings along the top (one screw and three plastic poppers) you can pull the top of the grille forwards and may be able to get your hand down to it and check it’s plugged in properly and there’s no sign of water ingress other than that I think it would be a dealer/warranty job

 

[petethegreek]

It’s strange to see a weird reading, if you unplug the sensor it shows no temp display so the fact it’s reading so far out shows it must be getting some signal back
The sensor is located behind the front grill if you bend down and look up through the slats you can see it, I think (and it’s only think) that if you open the bonnet and take out the four plastic fixings along the top (one screw and three plastic poppers) you can pull the top of the grille forwards and may be able to get your hand down to it and check it’s plugged in properly and there’s no sign of water ingress other than that I think it would be a dealer/warranty job

Thanks for that Pauly think I’ll book it in to the dealer, another day without the van.

 

[Ashok2429]

Thanks for that Pauly think I’ll book it in to the dealer, another day without the van.

Reigniting this post as I’ve got same issue on my T6, doesn’t fluctuate quite as much as yours did but driving in the rain today and dropped to -8 then back up to +15 once back in the sunshine.

Did the dealer rectify yours in the end?

 

[petethegreek]

They fitted a new sonsor and all was good after.

 

[Ashok2429]

Cheers for the quick reply, back to the dealer it is!

 

[Wafu]

Just to add to this thread, I have the same fault as you guys, the temp went from normal to random -figures, all the way up to -42 degrees, then it gives just dashes on the indication.
I’ve changed the temp sensor behind the grille, and plugged in my Carista. Job done I thought, but once I’d cleared the fault and the engine management light on the dash, the temp shows -16.5 with no engine management light.

I checked the code on the Carista and found ‘Outside temperature sensor: resistance too high - B103F1B code.

Anyone had this before? If so, can you point me in the right direction?

To help me understand the system, does the temp sensor wiring go through the multi plug on the offside, the one you disconnect when taking off the bumper?

Vehicle details are a 2018 Caravelle, Executive.

 

[Wafu]

Addition to the first post.
Bumper off, took the new sensor off and check the resistance, checked the old sensor and the resistance is near to the new one, concluded that I have two serviceable sensors.
Checked for an earth from the plug wires, one has a good .002 resistance to earth, the other is show 01 on my multimeter. This would say I have good earth and a supply wire to the sensor.
Next step is to see what voltage I have to the plug from god know where in the van.

Does the sensor have a fuse? If so where is it please.
Does anyone have a wiring diagram for the sensor and any attached systems?