Retrofit Cruise Control Diagnostics

[Moose94]

@Moose94 also visited Midlands HQ today.

View attachment 299009

Many thanks @Cv6benplus and @Alemito on your fault diagnosis.

Turns out there are multiple plugs in the module box in the engine bay that match the colour coding as well as available pin locations for this install.

Id plugged mine into the upper of the 2 plugs in sync, you actually need to plug into the standalone multiplug above the main positive feed. The BMW instructions the dealer gave me didnt specifically go into the images of said plug arangement and just shows the wiring diagram. @Alemito managed to find the correct wiring images and we managed to get it working fairly quickly.

Case closed, onto the three diff bushes this afternoon!

 

[enuff_zed]

Many thanks @Cv6benplus and @Alemito on your fault diagnosis.

Turns out there are multiple plugs in the module box in the engine bay that match the colour coding as well as available pin locations for this install.

Id plugged mine into the upper of the 2 plugs in sync, you actually need to plug into the standalone multiplug above the main positive feed. The BMW instructions the dealer gave me didnt specifically go into the images of said plug arangement and just shows the wiring diagram. @Alemito managed to find the correct wiring images and we managed to get it working fairly quickly.

Case closed, onto the three diff bushes this afternoon!

Excellent! Tbf, most observations were tending to suggest it was incorrect connections, but your headache has saved the rest of us from the same thing, so thank you very much for continuing the thread to it's conclusion.

 

[Moose94]

Excellent! Tbf, most observations were tending to suggest it was incorrect connections, but your headache has saved the rest of us from the same thing, so thank you very much for continuing the thread to it's conclusion.

Always keen to put resolutions in on forum posts and I hope it will help someone in the future!

If anyone is wanting to install cruise control, all in it was £300 direct from BMW for the stalk and loom, and if installed correctly, takes about an hour. You’ll need a Philips screwdriver and a crimp tool and that’s about it.

 

[Straba]

Sorry for a late reply, I think I could have helped you before visiting specialists., but was away for a few days.
For the N52 you have to search for a later year retrofit manual specifically, as most google hits list the prefacelift retrofit manual which goes directly to the DME pin. With the N52 it gets a bit confusing, as you are supposed to lay the blue wire into the IVM. And to get to it you naturally first go from inside the cabin into the large white box that already houses the DME. So you have to unwind the electrical isolation tape on the trunk towards IVM, do not use the other "easy" trunk with the plastic tube, pull the wire through and wrap it up again. The idea BMW had behind that was that the chassis side of wiring looms goes to the IVM and then in the IVM box the motor wiring loom is connected. to the chassis side. From the IVM to the DME the loom is already prewired for cruise control.
In the IVM you have said two connectors, so you have to use the "further away" one PIN 39, towards the engine (they are both 42 pin).

 

[0l0dom0l0]

Glad you got to the bottom of it, frustrating how it always seems so straightforward after the fact!!

When I fitted my cruise control the wiring diagram I was using was wrong - but the giveaway was that the pin I was trying to at the fuse box was taken.
Once I found the correct pins all was well, took longer than I'd like to admit though

 

[Moose94]

Glad you got to the bottom of it, frustrating how it always seems so straightforward after the fact!!

When I fitted my cruise control the wiring diagram I was using was wrong - but the giveaway was that the pin I was trying to at the fuse box was taken.
Once I found the correct pins all was well, took longer than I'd like to admit though

Annoyingly for mine, the other connectors also had pins 39 free, so its wasnt immediately obvious that i was trying to put the pins in the wrong connector!