Go Back   The 75 and ZT Owners Club Forums > The 75 and ZT Owners Club Forums > Technical Help Forum
Register FAQ Image Gallery Members List Calendar Mark Forums Read
Notices

Reply
 
Thread Tools Display Modes
Old 8th December 2018, 10:37   #41
SD1too
Doesn't do things by halves
 
SD1too's Avatar
 
Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model.

Join Date: Mar 2007
Location: Former Middlesex
Posts: 20,265
Thanks: 1,587
Thanked 3,749 Times in 3,181 Posts
Default

Quote:
Originally Posted by marinabrian View Post
All petrol models Simon there is one sensor and it is used to display the outside temperature on the IPK display.
On diesel models there are two sensors, one for use as in the petrol models ....
OK, so considering just the petrol models for the moment, is the outside temperature data sent by the IPK via the K bus to the BCU and ATC (HEVAC) ECUs derived from the temperature sensor in the bumper?

Sorry to be persistent about this but I think it's important to be absolutely clear.

Simon
__________________
"Whatever is rightly done, however humble, is noble."
Sir Henry Royce.
SD1too is offline   Reply With Quote
Old 8th December 2018, 19:37   #42
Alexandru.Edward
Regular poster
 
Rover 75 Saloon

Join Date: Apr 2018
Location: Bucharest
Posts: 53
Thanks: 56
Thanked 1 Time in 1 Post
Default

Plugged in the spare ECU today and the gauges moved, so not a wiring problem.

Put my main ECU back in, gauges dead again. Parked the car in a warm place for 1 hour and the gauges started to work. VIDEO
VIDEO - HRW works fine when the gauges work.

When I took the car outside again, the gauges started to work intermittent and after 10-15 minutes they went dead.

VIDEO - Intermittent work.
VIDEO - HRW no longer works.
Alexandru.Edward is offline   Reply With Quote
Old 8th December 2018, 20:19   #43
COLVERT
This is my second home
 
R75 Saloon.

Join Date: Feb 2009
Location: France/or Devon.
Posts: 14,003
Thanks: 3,851
Thanked 2,167 Times in 1,816 Posts
Default

Seems like you have a sensor that fails when it gets cold.


( Bit like me really. Lol. )---
COLVERT is offline   Reply With Quote
Old 8th December 2018, 21:21   #44
marinabrian
 
marinabrian's Avatar
 
MG ZT

Join Date: Jan 2011
Location: Newcastle Upon Tyne
Posts: 20,151
Thanks: 3,565
Thanked 10,837 Times in 5,718 Posts
Default

Quote:
Originally Posted by SD1too View Post
OK, so considering just the petrol models for the moment, is the outside temperature data sent by the IPK via the K bus to the BCU and ATC (HEVAC) ECUs derived from the temperature sensor in the bumper?

Sorry to be persistent about this but I think it's important to be absolutely clear.

Simon
Why not check the data traffic yourself Simon, I'm sure you could rig up an oscilloscope..........I certainly have in the past and then you will know for sure

Brian
marinabrian is offline   Reply With Quote
Old 9th December 2018, 08:44   #45
Phil-T4
I really should get out more.......
 
Phil-T4's Avatar
 
MG ZT-T, Rover 75 Tourer

Join Date: Mar 2011
Location: Olney
Posts: 2,969
Thanks: 245
Thanked 1,088 Times in 657 Posts
Default

Quote:
Originally Posted by marinabrian View Post
and the additional ambient temperature sensor as used only on diesel models, mounted on the PAS cooler pipework.
That is the bimetallic temperature switch which is hardwired into the FBH circuit, its only purpose is to switch on the FBH when the engine is running and the switch is closed at approx 5C air temp.
Phil-T4 is offline   Reply With Quote
Old 9th December 2018, 09:57   #46
HarryM1BYT
This is my second home
 
HarryM1BYT's Avatar
 
75 Contemporary SE Mk II 2004 Man. Sal. CDTi 135ps, FBH on red diesel, WinCE6 DD

Join Date: May 2010
Location: Leeds
Posts: 17,273
Thanks: 2,160
Thanked 2,061 Times in 1,586 Posts
Default

Quote:
Originally Posted by Phil-T4 View Post
That is the bimetallic temperature switch which is hardwired into the FBH circuit, its only purpose is to switch on the FBH when the engine is running and the switch is closed at approx 5C air temp.

That is correct as far as it goes, but don't some of the later diesels have an extra air temperature sensor in the turbo air duct?
__________________
Harry

How To's and items I offer for free, or just to cover the cost of my expenses...

http://www.the75andztclub.co.uk/foru...40#post1764540

Fix a poor handbrake; DIY ABS diagnostic unit; Loan of the spanner needed to change the CDT belts; free OBD diagnostics +MAF; Correct Bosch MAF cheap; DVB-T install in an ex-hi-line system; DD install with a HK amp; FBH servicing.

I've taken a vow of poverty. To annoy me, send money.
HarryM1BYT is offline   Reply With Quote
Old 9th December 2018, 10:10   #47
Phil-T4
I really should get out more.......
 
Phil-T4's Avatar
 
MG ZT-T, Rover 75 Tourer

Join Date: Mar 2011
Location: Olney
Posts: 2,969
Thanks: 245
Thanked 1,088 Times in 657 Posts
Default

Quote:
Originally Posted by HarryM1BYT View Post
That is correct as far as it goes, but don't some of the later diesels have an extra air temperature sensor in the turbo air duct?
Yes, the T21 sensor which monitors the charge air temp.
Phil-T4 is offline   Reply With Quote
Old 9th December 2018, 10:14   #48
Arctic
Give to Learn
 
Arctic's Avatar
 
Freelander 2

Join Date: Aug 2010
Location: West Midlands
Posts: 18,651
Thanks: 1,155
Thanked 6,407 Times in 3,874 Posts
Default

Quote:
Quote:
Originally Posted by SD1too View Post
OK, so considering just the petrol models for the moment, is the outside temperature data sent by the IPK via the K bus to the BCU and ATC (HEVAC) ECUs derived from the temperature sensor in the bumper?

Sorry to be persistent about this but I think it's important to be absolutely clear.

Simon
Quote:
Originally Posted by marinabrian
and the additional ambient temperature sensor as used only on diesel models, mounted on the PAS cooler pipework.

Quote:
That is the bimetallic temperature switch which is hardwired into the FBH circuit, its only purpose is to switch on the FBH when the engine is running and the switch is closed at approx 5C air temp.
Hi Lads
All interesting stuff and great reading for the other members & owners so they know which sensors are being talked about couple of photo's below.

ambient temperature sensor.
1

Place it should reside on the front bumper.
2

The bimetallic temperature switch, connected to the (FBH) fuel burning heater.
3

Close up of the sensor bolted to the PAS pipes by an 8mm bolt
4
__________________
Arctic
Givology Learn to Give
Everything is Achievable

ad altiora tendo.

Check out our Nano meet dates
http://www.midlandsnanomeets.co.uk/

http://www.the75andztclub.co.uk/index.php?thepage=howto

" You do the work , we supply the expertise "

Last edited by Arctic; 9th December 2018 at 15:12.. Reason: photo edit
Arctic is offline   Reply With Quote
Old 9th December 2018, 10:17   #49
Phil-T4
I really should get out more.......
 
Phil-T4's Avatar
 
MG ZT-T, Rover 75 Tourer

Join Date: Mar 2011
Location: Olney
Posts: 2,969
Thanks: 245
Thanked 1,088 Times in 657 Posts
Default

And to answer the question why the HRW stops working when the can-bus controller dies.

No RPM signal = engine not running = HRW cant be switched on.
Phil-T4 is offline   Reply With Quote
Old 9th December 2018, 10:39   #50
Phil-T4
I really should get out more.......
 
Phil-T4's Avatar
 
MG ZT-T, Rover 75 Tourer

Join Date: Mar 2011
Location: Olney
Posts: 2,969
Thanks: 245
Thanked 1,088 Times in 657 Posts
Default

Quote:
Originally Posted by SD1too View Post
OK, so considering just the petrol models for the moment, is the outside temperature data sent by the IPK via the K bus to the BCU and ATC (HEVAC) ECUs derived from the temperature sensor in the bumper?

Sorry to be persistent about this but I think it's important to be absolutely clear.

Simon
For all models, the IPK broadcasts the outside air temp (along with other data) so that anything on the K-Bus can read it and use it if required.

So yes the BCU does receive it, however the ATC is NOT on the K-bus network it has its own datalink directly to/from the BCU.
Phil-T4 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 04:54.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright © 2006-2023, The Rover 75 & MG ZT Owners Club Ltd