L322 L322 TDV8 electrical Gremlins

So after a few years without a Range Rover in my life I’ve gone and bought another. 2007 TDV8 Vogue SE with 166000 miles.
Purchased with faults, I must be mad.
On tickover all is good, revs nicely and only an adaptive light warning on the dash.
Drive Evan an inch and the dash goes off and on and off, once stationary the dash comes back on and showing suspension, Hdc and handbrake fault.
Drives ok, gearbox could do with a flush but other than that it’s just the dash issues.
Disconnect all four abs sensors and the dash stays on with ABS warning, doesn’t help if disconnected individually.
What on earth could be wrong? I’ve checked all fuses including the hidden ones. Live data shows no signal from the wheel sensors but surely they can’t all have failed.
Main fault codes are invalid data from dynamic control module. U0416.
Sorry for the long post.
Any help would be appreciated as I’m at a loss where to look now.

Bad earth somewhere? Or as all systems are interconnected on the CAN BUS, a duff ABS ECU.

I thought earth but when the dash goes off and on etc it’s very consistent, not like a loose wire or intermittent bad earth, it’s literally on, off, on, off.
Is there a way to test the abs ecu? Do they have to be coded? I’m conscious that the previous owner threw money at new parts without actually finding the fix, I’ve got 4 new abs sensors that came with the car, might just change one to confirm it’s not all four sensors.

Would a faulty ABS ecu not cause an ABS fault on the dash? I only get this if a sensor is disconnected.

Have read an alternator can cause a flashing dash, I’ll test it but would expect a battery light to be showing if that was the case .

youmitegetian said:

Have read an alternator can cause a flashing dash, I’ll test it but would expect a battery light to be showing if that was the case .

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A faulty alternator may not show the battery light on the dash.

Oh ok, thanks Datatek, I’ll check the voltage later. I cleared loads of faults that mostly voltage issues and it’s got a new battery so I wouldn’t be surprised if it’s at least partly down to battery/ alternator fault

Ok so I’ve checked the alternator and battery and charged the battery over a few days with no difference.
I’ve also replaced the abs with a know good unit from an identical car, no change at all. I’ve checked quite a few earths although still more to look at, any other things I could check? Really don’t want to have to send to a garage who will want to replace parts without knowing the fault.

Interestingly I put it in low range to test it and the dash doesn’t flash now but I can’t get it out of low range for some reason.

youmitegetian said:

Ok so I’ve checked the alternator and battery and charged the battery over a few days with no difference.
I’ve also replaced the abs with a know good unit from an identical car, no change at all. I’ve checked quite a few earths although still more to look at, any other things I could check? Really don’t want to have to send to a garage who will want to replace parts without knowing the fault.

Click to expand...

How did you check the alternator? A duff rectifier diode might only be seen with a scope

Lol I don’t even know what that is, I checked the voltage on tickover.

youmitegetian said:

Lol I don’t even know what that is, I checked the voltage on tickover.

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So, what voltage did you have and did it fluctuate at all?

Was 14.4, think it did move .1 or .2 but can’t remember now