I've attached an extract from the workshop manual for the PAM that also supports the conclusion that its down to coding..

Have you checked the front PDC values too? do they all make sense? I see a lot of (Non-JLR) park sensor issues where there is no DTC set because the value is 'in range' but implausible.

For example, this connector suffered water ingress that travelled through two other connectors to put water into a much more expensive component, even though there was no DTC relating to the forward-facing RADAR(which it is the connector for), but there was to loss of comms to the PAM - eventually.

Click image to enlarge

All plugs look fine, no sign of corrosion on the plugs or the connectors on the old unit. All live values for the sensors are plausible. live values for the switch and LED are also reported correctly.

The old module being literally full of water is what led me to conclude it was probably faulty

If it was another part of the system then I would expect other errors to be present in IID

edit - the old PAM module doesn't even appear on the CAN bus, IID can't see it at all and there is no sound or LED.

Thanks for the suggestions though

My point is, if all around is dry and there is no signs of ingress, then the water in the PAM is a symptom, with the cause being elsewhere - possibly also causing comms issues with your replacement module.
That DTC is a very broad-brush and can indicate issues other than configuration, all I'm saying, is don't take the WSM to be 'the Bible', for diagnosis it's a guide, not a gospel.

icarus76 wrote:

I've attached an extract from the workshop manual for the PAM that also supports the conclusion that its down to coding..

unfortunately, Pat @ IID has confirmed the IID can't reprogram it..

Are the PAM part numbers the same?
Causes of the DTC are vehicle/component mismatch, along with previously used on another vehicle.

There is also this which may or may not be relevant, https://www.disco4.com/forum/topic173944.html?view=next I don't use IID but it appears to suggest that re-applying the CCF and letting the vehicle shut down gracefully, cleared or at least 'got around' the DTC.
I remember there was also an issue with reman. Haldex units on FL2's where the VIN had been coded to the control module entirely randomly during original production but not cleared at re-manufacture, there are / were companies that are able to clear / reset VIN coding in Haldex modules but I have no idea of what kit they used.

Part numbers are identical - thanks for the link, got to be worth a go!

Hi All,

Just to close this post - I purchased a brand new unit from Island 4x4 and it worked as soon as I plugged it in. Scan with IID shows no faults and the correct VIN number.

Interestingly the unit with the VIN error did, for a few seconds at startup, appear to work - sounders would beep if I was parked close to an object. Then the light would flash six times, the sounder give a continuous beep and no further signs of life.

I'm concluding from this that the module is coded to the car and so only brand new units will work - this may be specific to 2012 model years..

Thanks everyone for the suggestions and help.