Anyone near me want to play with diagnostics?

[pscan.eu]

I have had some recent luck with 75s. It seems that like buses three have come at once.
Rob Bell has lent me his ZT-T diesel for a few weeks, and I have pretty much done the GM6 already and I started looking at climate control and instruments.
At the same time I found an early 1.8 75 that was been abandoned and about to be scrapped, I managed to remove I think every ECU from that so I can make my own "75 in a box".
I also found a ZT V8 in Ruislip.
I went and knocked on the guys door last night and he is willing to let me play with it.

So here is the question. What is the same about a V8 as other 75s and what is different? So what do I need to focus on whilst I have access to this guys V8 in Ruislip?

His car has factory reversing sensors so I will play with that as my other guinea pigs don't have that.
Also the Ford engine ECU is specific to the V8, but I already have a Ford Mustang ECU and so it will be interesting to see to what extent they are different or the same.
The obvious thing is the intermediate ECU (the one that converts from Rover/BMW protocols to Ford). I know that these are difficult to find and so that's one I should obviously concentrate on.

I am guessing that GM6, SRS, Instruments, EWS3, Climate control will all be the same as a non V8? Can anyone on here clarify?

thanks, Philip

[Burwell Mike]

I am guessing that GM6, SRS, Instruments, EWS3, Climate control will all be the same as a non V8? Can anyone on here clarify?

thanks, Philip

I think the climate control on V8's has a different ecu. Some time ago I fitted an aftermarket control panel from Mat at DMGRS which would not work on the V8 (full heat whatever setting it was on). This panel works perfectly on standard cars so something is different on the V8. Sorry can't help with other items.

Mike

[David]

I think the climate control on V8's has a different ecu. Some time ago I fitted an aftermarket control panel from Mat at DMGRS which would not work on the V8 (full heat whatever setting it was on). This panel works perfectly on standard cars so something is different on the V8. Sorry can't help with other items.

Mike

Odd thing is that a regular 75 panel (2000 and 2003, MGR) works just fine in my R75V8 and vice versa. Was playing around swapping them a few years back to see if that improved things, which it didn't, of course. Part number is identical on all of them, so there is something odd about the 'after-market' panels (MG7?) only perhaps. Differences in the HVAC design between 260 and RV8 are well known of course, as well as the obvious major differences between V8/non-V8 of both variants. Looks like that stretches to other HVAC electronics bits-and-pieces rather than the panel and its packaged electronics, from what you say Mike.

David

[Burwell Mike]

Hi David,

As you say there must be a subtle difference in the outputs of the aftermarket panel that messes with the V8 HVAC signals to the heating valve. There is a HVAC ECU on V8's that I can't find listed as a standard 75/ZT item. Unfortunately as Rimmers no longer provide part numbers on their listings for NLA items it is difficult to do a conclusive search, but I cannot see the same item on the 75/ZT heater assemby diagrams (Item 5 on the V8 diagram).

I have often thought that gremlins in this additional ecu is what causes heating problems on some cars and not others, or possibly just a dodgy connection to it. The HVAC has always worked perfectly on #431 (touching wood as I type!) but fitting the aftermarket panel showed the ecu was sensitive to different inputs

Mike

[David]

.... Unfortunately as Rimmers no longer provide part numbers on their listings for NLA items it is difficult to do a conclusive search, but I cannot see the same item on the 75/ZT heater assemby diagrams (Item 5 on the V8 diagram)...
Mike

Should be possible to find that on the EPC. Mine has gone on the blink, I'm afraid (or to be more precise the only old Windows XP computer I still have that will run the EPC).

David

[re-tread]

Hi David,

As you say there must be a subtle difference in the outputs of the aftermarket panel that messes with the V8 HVAC signals to the heating valve. There is a HVAC ECU on V8's that I can't find listed as a standard 75/ZT item. Unfortunately as Rimmers no longer provide part numbers on their listings for NLA items it is difficult to do a conclusive search, but I cannot see the same item on the 75/ZT heater assemby diagrams (Item 5 on the V8 diagram).

I have often thought that gremlins in this additional ecu is what causes heating problems on some cars and not others, or possibly just a dodgy connection to it. The HVAC has always worked perfectly on #431 (touching wood as I type!) but fitting the aftermarket panel showed the ecu was sensitive to different inputs

Mike

If the ECU you are thinking about is the one mounted on the heater box under the dash then it is part number JFW000011. I was hoping that changing that would sort out my heater gremlins but alas no.

[Burwell Mike]

If the ECU you are thinking about is the one mounted on the heater box under the dash then it is part number JFW000011. I was hoping that changing that would sort out my heater gremlins but alas no.

Yes that looks like the one! Oh well there goes my theory about the HVAC ecu causing the problems. Sorry that you had no joy after changing it Dave.

Mike

[SCP440]

Yes I did the same, it was like a furnace. Odd that the control panel is the same though.

Steve