Thread: What happened to your D3/D4 today?

Originally Posted by Eric SDV6SE

Height sensor calibration is out of whack as the new arms change the ride height relative to what the sensor knows. You need to redo the calibrations per corner. Measure from the hub centre to underside wheel arch, 465mm front and 485 rear. The actual measured difference is the offset you need to add or subtract from the current value that the sensor is keeping the wheel at via the air strut and solenoid in the valve block.

Did the guided calibration. It was very close to correct. Arm was an on / off process with the same arm.

Might do calibration again as it’s the other codes that puzzle me.

Originally Posted by Eric SDV6SE

Height sensor calibration is out of whack as the new arms change the ride height relative to what the sensor knows. You need to redo the calibrations per corner. Measure from the hub centre to underside wheel arch, 465mm front and 485 rear. The actual measured difference is the offset you need to add or subtract from the current value that the sensor is keeping the wheel at via the air strut and solenoid in the valve block.

This makes no sense. The same sensor is in place. Unless the fixture point has move substantially (unlikely), or the bushes were completely collapsed, there should be minimal change in sensor value and ride position. Even if there is, it should be minimal and not cause faults and only cause a slightly offset ride height.

Why is it always the rear left.

5BD57E2D-555C-4CB5-A6D6-4EF7C87EBF17.jpg

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Originally Posted by Moggymitch

Why is it always the rear left.

5BD57E2D-555C-4CB5-A6D6-4EF7C87EBF17.jpg

Perhaps the FRONT left kicks up bad stuff from the side of the road.. who KNOWS?

Originally Posted by Moggymitch

Why is it always the rear left.

5BD57E2D-555C-4CB5-A6D6-4EF7C87EBF17.jpg

Every tyre shop will tell you that is the most common tyre punctured.

Probably a few reasons,such as most of the rubbish ends up on left side of the road,and its flicked up by the front tyre.
Left side of the road is also usually the worst part of the road.

FWIW,i ran BFG on my D4 for 10yrs,travelled all over the countryside,and had one slow leak in that time,a large Teck screw,left rear,tyre was worn out anyway,so it didnt get repaired the whole set were replaced.i actually never used the POS jack.

Originally Posted by DiscoJeffster

This makes no sense. The same sensor is in place. Unless the fixture point has move substantially (unlikely), or the bushes were completely collapsed, there should be minimal change in sensor value and ride position. Even if there is, it should be minimal and not cause faults and only cause a slightly offset ride height.

Maybe, all i know is that after replacing all control arms, I had to reset my calibrations. I suspect that once you disconnect the linkage from the arm, the sensor 'loses' its reference point and resets itself. No fault of the sensor though. I had 20-40mm discrepancies between left and right.

Originally Posted by Eric SDV6SE

I suspect that once you disconnect the linkage from the arm, the sensor 'loses' its reference point and resets itself.

No, the sensor is effectively a rheostat, outputting a voltage dependent on the arm angle. The sensor does not get calibration data from the suspension ecu.

Originally Posted by Graeme

No, the sensor is effectively a rheostat, outputting a voltage dependent on the arm angle. The sensor does not get calibration data from the suspension ecu.

I agree - I’ve got the adjustable 3 position rods and when you adjust these the car just jumps to the next height level without faults.

It’s the other comms errors I’m worried about some other gremlin or is this normal with slow to fill main warning?

I’ve reset again and am currently fault free just in case the struggle to refill all corners made it extra grumpy for a few days.