Thread: Diagnosing weirdness... Help...

Originally Posted by FNQLR;[URL="tel:3229350"

3229350[/URL]]Is a replacement instrument panel plug and play?

I was told I need to buy the BCU, IP and key barrel as a kit - cant just swap the panel.
(all because the tach has died)

I swapped mine cos it was cracked. No problem as long as you have a nanocom or similar. Just pay attention to what sierrafery said about syncing the odometer. Sync the odo to the BCM and not the other way around. Everything will work fine. If you don’t have a nanocom then the odometer will flash as a fault warning.
I guess someone wants to sell you a bunch of stuff that you don’t need.

FYI, I swapped mine months ago, long before my current problem. The instruments are possibly the only things still working properly 😂

BCU issue would be most likely if the window issues was only on the fronts(and not rears too).
As far as I can understand it, rear windows don't get power or command via the BCU, but the IDM in the fusebox, which then operates the relay in the fusebox for them too.

So fronts are controlled by BCU, rears are controlled by IDM/fuse at the fusebox.
The fact that they work via nanocom rules out fuses, so that only leaves the BCU, the switches or the earths .. or possibly all three issues. ie. there is a possibility that you may have multiple issues.

For sure tho, the one common denominator in all three possibilities is the earth header under the centre console. If you have RAVE going, search for C0552. It's a light grey connector with 10 wires(all black).
All the switches get their earthing from this connection point.
The rear motors get their earth from the same connector, pin 7, and if they operate via nanocom means that this earth must be good.

The earth pins at the connector for each switch is at 1, 2(fronts) and 8, 9(rears, directly to the console switches, and then indirectly to the rear door switches).

The other pins/wires on this earth header are as follows:
pin 3 is for the seat belt switch
pin 4 is earth for trans selector, difflock(where fitted), and hi/lo selector switch to illuminate relevant bulbs.
pin 5 seems to do nothing that I can find
pin 6 is for earth to LH rear door lock
pin 10 is for earth to RH door lock.

IDM does help manage/control central locking too.

Originally Posted by Tins

... Sync the odo to the BCM and not the other way around.

What i said is to NOT do that ^^^ (unless you are certain that the BCU has lower mileage stored cos if it's higher you end up with that on the odometer)... IMO those synking BCU to odo or vice-versa are to be used only if a "virgin" unit is fitted, for SH ones those functions are useless better not use any of them only the odometer error warning has to be disabled for it to not flash nothing else.

Originally Posted by sierrafery

What i said is to NOT do that ^^^ (unless you are certain that the BCU has lower mileage stored cos if it's higher you end up with that on the odometer)... IMO those synking BCU to odo or vice-versa are to be used only if a "virgin" unit is fitted, for SH ones those functions are useless better not use any of them only the odometer error warning has to be disabled for it to not flash nothing else.

Sync that way means the odo reading would be accurate. I was specifically replying to the query re replacing the instrument panel, NOT the BCU. I got what you were saying re my situation, where the BCU is the item being replaced. When I replaced the panel in mine the replacement read higher than mine, and I wanted it to accurately reflect my car, not the donor car.

Curious though, which function in the Nano disables the error warning? I haven't seen that in my burrowing.

Originally Posted by Tins

Sync that way means the odo reading would be accurate. I was specifically replying to the query re replacing the instrument panel, NOT the BCU. I got what you were saying re my situation, where the BCU is the item being replaced. When I replaced the panel in mine the replacement read higher than mine, and I wanted it to accurately reflect my car, not the donor car.

Curious though, which function in the Nano disables the error warning? I haven't seen that in my burrowing.

Sorry, you have a point, unless the replacement odo has a higher mileage cos then nothing happens, AFAIK it doesnt go lower what ever you do.... the odometer error warning is in the BCU - settings - transm/lock/warn - last page, must be set to "not fitted"

So... Had the battery off while I was doing stuff. chasing an oil leak (!), replacing the itty bitty hose from the oil cooler while the turbo was off, etc. Put it all back, but haven't started it as I wanted daylight and no rain to bleed the cooling system. But I did turn it on, and the PRNDL indicators are working again.... Haven't tried anything else, because of said rain, but fingers crossed. Maybe it resets to factory when disconnected for some time. I know from my brief encounter with a Nissan 200SX that that car's does. Not sanguine, but hey. Still going to get another BCU cos it would be silly not to.
Of course, knowing my luck, the thing will probably have immobilised itself... The little diode is blinking ( slow ), but I had that turned off.

Too good to be true, of course. No change now it's running. At least it's not immobilised, but it did flatten the battery... Other stuff to do before I chase that.

Another area of suspicion is the internal fusebox. Heard stories about them and corrosion... Mine isn't as bad as some pix I've seen, but a cleanup, or replacement with my spare, might be worthwhile.

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