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- Dazz360
- Member Since: 07 Aug 2025
- Location: Walsall
- Posts: 133
I’ve found this
Is the junction box central the fuse board in the boot ?
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- Mole HD
- Member Since: 18 Nov 2024
- Location: Orkney Islands
- Posts: 444
So it's covered by a relay within the LINBUS. Might be worth sticking that relay on a tester.
A tenner on Ebay or Amazon...
I've had one for years in the toolbox... as much as it's hardly ever been used in anger, it's handy for checking starter and headlight relays and the like. It's a bit easier and quicker than the old school method of running a 12v supply through the pins on a relay and listening to hear if it clicks.
Better to have it and not need it rather than t'other way around
.
Last edited by Mole HD on 4th Oct 2025 6:04 pm. Edited 1 time in total -
- Dazz360
- Member Since: 07 Aug 2025
- Location: Walsall
- Posts: 133
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- Mole HD
- Member Since: 18 Nov 2024
- Location: Orkney Islands
- Posts: 444
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That relay in the diagram is in the rear junction box in the right side of the boot. Relay 31p according to the wiring diagram you showed.
The fusebox diagram shows it as R1 on the diagram though...one with the little fan on it.
Last edited by Mole HD on 4th Oct 2025 6:11 pm. Edited 1 time in total -
- Dazz360
- Member Since: 07 Aug 2025
- Location: Walsall
- Posts: 133
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It says air suspension -
- Mole HD
- Member Since: 18 Nov 2024
- Location: Orkney Islands
- Posts: 444
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- Dazz360
- Member Since: 07 Aug 2025
- Location: Walsall
- Posts: 133
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- Dazz360
- Member Since: 07 Aug 2025
- Location: Walsall
- Posts: 133
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Mole HD wrote:
So it's covered by a relay within the LINBUS. Might be worth sticking that relay on a tester.
A tenner on Ebay or Amazon...
I've had one for years in the toolbox... as much as it's hardly ever been used in anger, it's handy for checking starter and headlight relays and the like. It's a bit easier and quicker than the old school method of running a 12v supply through the pins on a relay and listening to hear if it clicks.
Better to have it and not need it rather than t'other way around
.
Ordered -
- Mole HD
- Member Since: 18 Nov 2024
- Location: Orkney Islands
- Posts: 444
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I think we're getting too complicated the further we go down this road...the IID DTC fault refers to a physical component not working. If it had been that relay or anything else tied into the QCCM module...it stands to reason that your heater, audio or something else wouldn't be working either.
It all points to a dodgy FBH to my eyes...whether the fault is electrical or mechanical in nature reamains to be discovered...it might be stuck through never being used and just needs a dunt with a tap-o-meter (2lb engineers hammer) or something more mechanical in nature rather than electrical
Definitely worthwhile investigating though... -
- Dazz360
- Member Since: 07 Aug 2025
- Location: Walsall
- Posts: 133
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Just found this
I’ll try cleaning contact’s first -
- Mole HD
- Member Since: 18 Nov 2024
- Location: Orkney Islands
- Posts: 444
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The 'contact cleaning' they refer to is a JLR diagnostic tool option to force the usually automatic contact cleaning function done by the QCCM module as part of it's normal operation. If it fails...they replace the entire RJB (Rear Junction Box) by the look of things... nothing like saving the customer some pennies by acting like proper mechanics and just fixing the problem
Don't think the IID tool has that as an option, I haven't checked.
Last edited by Mole HD on 4th Oct 2025 6:49 pm. Edited 1 time in total -
- Dazz360
- Member Since: 07 Aug 2025
- Location: Walsall
- Posts: 133
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- Mole HD
- Member Since: 18 Nov 2024
- Location: Orkney Islands
- Posts: 444
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- Dazz360
- Member Since: 07 Aug 2025
- Location: Walsall
- Posts: 133
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- Mole HD
- Member Since: 18 Nov 2024
- Location: Orkney Islands
- Posts: 444
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