Well that's not inspiring. Do we think the ACC range got a different bumper? I've had a lot of ACC vehicles and none of them have ever had the radar unit blocked by the bumper.

No the bumper is the same with or without the radar unit. My radar unit has gone faulty after working for 8 years.

How did you know? Codes?

Just check for faults and I have this. Any idea what this means?

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Maybe re-check your CCF parameters. If you've enabled stop&go then try with that feature disabled.

Mine showed radar unit blocked shortly after every start-up which indicates that it isn't seeing a reflected beam. This could be caused if the unit is so misaligned that the reflected beam isn't seen, but it isn't misaligned, or that the transmitter or receiver has failed. I don't have access to a monitor for 77 GHz signals so I can't check if the transmitter is working, not that I'm likely to be able to repair it.

Tried both combinations unfortunately. I'm wondering if my vin is close enough to the older vin that it needs the ACC module in the trunk? It's BA35***

You acquired switch LR023197. My investigations revealed that the switch part number for BA349700+ the switch part number is LR029644. I don't know if that is due to a change in operation or just a superficial reason such as a new colour or style.

What prompted you to get that part number?

I actually ultimately ended up with switch LR057123 after lots of back and forth with Scudaria.

I see that my number has been superseded by your number, so the switch isn't an issue.

Pat shot me an email back and he thinks the lack of input shouldn't be an issue, but I can't get past the blinking ACC light. I wonder if because my vin is so close to BA3 that may be it still needs the rear acc module?

Microcat 2012 shows the 5.0 NA and SC having both a 2nd radar unit and the adaptive speed controller in the rear, with no end to the VIN range. However IIRC earlier in this thread at least one 5.0 owner only had to install a single radar unit and no rear controller, so Microcat 2012 must not be telling the whole story. The rear controller changed part numbers from VIN BA334343 but the earlier number supersedes to the later number anyway.

I must need the rear acc module. Got a part number for my vin?

Looking back through the thread I see two options. AH42-14B588-AA or LR025949 (maybe they're the same?).The former option is only $28 on eBay vs $180.

The part number is LR025949 whereas I understand that the other number is a production/assembly code.
I would check if the connector exists as evidence that it is expected.

Edit: It appears that MY12 still uses the module judging by adverts from wreckers.

No connector unfortunately

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I couldn't find anything in the wiring diagrams including the HS canbus diagram for it either.
Maybe try to have a chat with a wrecker selling the module - there's one on ebay showing a MY12.