Thread: Warning Will Robinson - multiple D4 fault alerts!

Originally Posted by Graeme

I assume that it is only at access height, being safe height to which the suspension is lowered when a brake system fault that could be a safety issue is broadcast on the HS can-bus, eg a failed wheel speed sensor. If so then the suspension system is still working, just limited to the low height and therefore by modifying the height signals to make the vehicle appear lower the suspension will be raised until the sensor signals are as expected. Llams high raised will raise to normal height then if the red button is pressed, medium raised becomes normal height and high raised becomes off-road height.

This is correct - although sometimes the faults will stop the compressor from also running and will only allow lowering and not raising. With the GAP tool you can force the compressor to restart and start lifting before the faults stop it again.

So as long as you reset what the system considers as being the lowered height using either Lift rods, Llams, or the GAP tool height modes you can get around this problem.

Latest report from Dave at TVR - diagnostics show there is a hard fault - no continuity- between the ABS sensor and the wiring loom at the front of the car, which he says indicates a broken wire somewhere. I'm told that finding the broken wire and fixing it is a big job, in the meantime he's offered to jerry-rig a wire from the ABS sensor through the chassis to the connector on the loom. According to the wiring diagram (I'm advised by someone else on a Disco FB forum) is behind the left headlight somewhere.
I guess the sensible approach, before going to the trouble of feeding a wire all the way up through the chassis and firewall, is to run a test wire around the outside of the car to the connector first and see if that clears the faults.
That's a job for the next visit to the Indy. In the meantime, the car is at home, and this morning I'm going to try raising the suspension to about normal height using the GAP tool and see if that works. At least it'll be driveable, even thought the various faults are still apparent. Will advise.

Greg - with the GAP tool, reset normal height to say +50mm, then go to the suspension module under service/test and you will see an option to re-enable the EAS. This should allow you to select raise height. Might take a few attempts but normally you can get it high enough so that next time you go for a drive and it attempts to drop to the “lowered height” due to the faults it will now settle at more like the normal height.

The ABS module is attached to the brake master cylinder.

Originally Posted by DiscoDB

Greg - with the GAP tool, reset normal height to say +50mm, then go to the suspension module under service/test and you will see an option to re-enable the EAS. This should allow you to select raise height. Might take a few attempts but normally you can get it high enough so that next time you go for a drive and it attempts to drop to the “lowered height” due to the faults it will now settle at more like the normal height.

Mmm...have been trying that. As you'll see from the screen shots, I can't even get the height control working in the GAP tool before going to Service/Test. I also just did another fault test and it came back with the results as you'll see...

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Okay so I've gone into the Service/Test screen and re-enabled the EAS, then as instructed, attempted to raise the height using the console switch, to no avail. I've also gone into the height control settings and attempted to re-set the default height to plus 39mm, still no effect.
Anything more than this is probably beyond me, and I'll just have to wait till the Indy is able to dive in again on Tuesday.

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I'd be having a critical look at the wire between the sensor and where it enters the body, looking for a chaffed spot from having rubbed on a clip or body part.

If a temporary wire is run it should be a shielded wire, although I suspect it would take more time to install the wire than find the fault. Intercepting the wires at the ABS module exposes the wire to the risk of moisture getting in at a later time.

If diagnostics detected an open circuit then the shield/earth could be the cause, although the shield might retain continuity even though the signal wire has been cut.

Originally Posted by Graeme

I'd be having a critical look at the wire between the sensor and where it enters the body, looking for a chaffed spot from having rubbed on a clip or body part.

If a temporary wire is run it should be a shielded wire, although I suspect it would take more time to install the wire than find the fault. Intercepting the wires at the ABS module exposes the wire to the risk of moisture getting in at a later time.

If diagnostics detected an open circuit then the shield/earth could be the cause, although the shield might retain continuity even though the signal wire has been cut.

Good advice, thanks Graeme, that'll be my first suggestion when it goes back to the workshop on Tuesday.