Big Bang isn't normal. So you drove it above 45mph and no red fault? Hmmm....

....my 256 reference was not to gallery pressure but rather to the upper calibration limit per the IIDTool. I think it's a unitless number.

 

Sounds like releasing air from a tire but louder and sharper in release.

 

Sounds like a line is not hooked up right, maybe? Not that intake or exhaust lines would affect anything though. Just not good to have them open to the elements.

 

Well the team at GAP came back overnight. Brilliant service on their part. Said these codes are very common.

C1A13-64 could be:
Reservoir value block pipes incorrectly installed (unions reversed)
Exhaust valve stuck closed.
Exhaust value does not hold minimum retention pressure.
Exhaust valve coil/wiring short circuit.
Gallery pipe blocked/damaged.
Ai suspension exhaust silencer blocked/restricted.
Axle Valve block pipes connected incorrectly.
Pressure Sensor Fault.

C1131-92 (intermittent code) could be:

Air Spring pipe air leak.
Suspension air supply unit failure.

So, I've got some troubleshooting to do. More than frustrating as I've found all of this out in a little over a day. No mention of the computer module which the mechanic said it is likely to be...

Cannot thank everyone enough for contributing and getting this LR3 back on track!

 

The GAP team is excellent!

Dakota already suspected the hoses being reversed at the valve block....I'm betting on that one!

 

Case of beer to the person that predicted the right cause, PA laws permitting!

Thanks again everyone. Will be back with an update.

 

So, who wants to claim that case of beer?

Weather has been bad so thought I would try another Rover Specialist, whilst we are all on lockdown going nowhere.

Ultimately the 2 lines were reserved in the main valve body. Everything now working as it should be.

So the replacement compressor and exhaust valves were not necessary but these were parts I was looking to replace in the near future given the age of the truck.

Frustrating to say the least, but can't thank everyone enough for their input and support. Looking forward to fetching later.

Thanks again.

 

Dakota gets the beer....DAMNIT!

Glad you got that sorted out...

 

You can have the beer houm_wa, you earned it too. Besides, I only drink fine wine!

And ditto, glad it is all sorted out and thanks for the update!