Volvo remote behavior

brobert · Post by **brobert** » 28 Jan 2024, 18:54

Greetings,

My 2006 V70 only came with one key+remote

I've been wanting to add another key+remote for a while.
I got a new Volvo key+remote and wanted to use D5T5 but they seem overly busy (no reply to emails) so I wait.

I have read elsewhere that remotes are registered in the UEM and ID48 key transponders in the CEM and ECM.
For fun, I tried (and have succeeded) in transplanting a used XC90 remote into my UEM.
I got the codes from the XC90's UEM and inserted them at the right hex locations in my UEM's EEPROM:
04h - 07h 1st remote ID
08h - 0Bh 2nd remote ID
0Ch - 0Fh 3rd remote ID
etc.
3Ch - 43h 1st remote Keeloq code
44h - 4Bh 2nd remote Keeloq code
4Ch - 53h 3rd remote Keeloq code
etc.
Before someone asks, I did all this work using the Orange5 reader/writer.

Now for my question:
When my car has the 1st key inserted into the ignition barrel, the car does NOT react to the 2nd remote.
When that 1st key is removed from the ignition barrel, the second remote works just fine.
I haven't checked the Owners' manual but presume that this is normal behavior?

/BR

npexcept · Post by **npexcept** » 28 Jan 2024, 19:21

At first: very interesting! This might come handy form me soon!

I did use d5t5 to add 2 new keys (but not remotes) to my 2003 xc90.

With remote, do you mean the fob to remotely lock/unlock the car?
Are you trying to lock the car whilst with a key in the ignition?
Don't really understand (english isn't my first language)

This is from the owners manual: So maybe the transmitter is blocked with a key in ignition. Can test that on my XC90 tomorrow.

: lock1.png (36.27 KiB) Viewed 635 times

NOTE: To help prevent accidentally locking the keys in the vehicle, the central locking system is designed to unlock the doors immediately if the key is left in the ignition switch, the vehicle is locked using the lock button on the door and the door is then closed. A sound from the lock will be audible at this time.

Please note that this function will not unlock the doors if the engine is running.

brobert · Post by **brobert** » 28 Jan 2024, 23:03

Thank you for the Owners' manual excerpts - that is probably what I'm experiencing.
I was not aware of these Volvo features (still cannot find the warnings in my V70 manual).
It will be interesting to see how your XC90 behaves.

To answer your questions:
Correct, I was talking about the fob to lock/unlock the car (part of the flip key).
Yes, I would like to lock/unlock the car while the engine is running.

I skipped a couple more complications in manually adding a remote to the UEM but
it is all possible. Also, being able to read/program the modules is quite satisfying.
There is mystery around the UEM so I was getting curious and nervous at the same time.
My goal is to backup most of my modules so that I'm never in need of the dealer in case of failure.
I am disappointed by the bottomless greed from the manufacturer and dealers when you are stuck with a defective car.

Post by **jonesg** » 30 Jan 2024, 09:27

googled it,

https://www.aliexpress.us/item/32568059 ... pt=glo2usa

then found youtube videos, good for some but my car would never run again if i touched a circuit board.

brobert · Post by **brobert** » 30 Jan 2024, 10:00

jonesg wrote: ↑30 Jan 2024, 09:27 googled it,

https://www.aliexpress.us/item/32568059 ... pt=glo2usa

then found youtube videos, good for some but my car would never run again if i touched a circuit board.

Yes, that's the unit but be aware that this is a clone (no upgrade possible and possibly dubious quality).
In my experience, you should not fear opening your Volvo modules with some precautions and admittedly a little luck.
You can make your own luck by buying a unit at the local boneyard (or eBay) and experiment with that spare unit.
Once successful, you know what you are doing and now have a spare if things ever go bad down the road (no pun intended).
Another trick for the DDM and PDM: buy the PDM as it only has one switch and the boneyard will charge you less

The microprocessor PCB is identical between the DDM and PDM (except for one connector).

Since the UEM is packaged in a tricky way and a pain to remove, I got fed up with opening the unit to experiment.
After some thinking, I added a (flush) programing port at the bottom so now I just disconnect the UEM from the car and program in-situ.
By the way, only four wires are required to read/write many modules (UEM, REM, PDM, DDM, DIM, CCM).

/BR

Post by **jonesg** » 30 Jan 2024, 11:43

If I ever get to a decent junkyard again I'll pull those modules and give it a try.
No volvo boneyards here.

WhizzMan · Post by **WhizzMan** » 02 Feb 2024, 07:50

Very interesting. Could you just write your data or did you have to do some form of checksum?
Additional question: did you just add the IDs that were on the printed label of the box of the factory-new remote or did you copy them out of another UEM and did you use a 2nd hand remote that came with that UEM?

brobert · Post by **brobert** » 02 Feb 2024, 08:17

WhizzMan wrote: ↑02 Feb 2024, 07:50 Very interesting. Could you just write your data or did you have to do some form of checksum?

On my 2006 V70, there is no checksum or CRC.
I just added the data, rebooted the car and that was it

Once in a while, it's nice to get a break!
/BR

WhizzMan · Post by **WhizzMan** » 02 Feb 2024, 09:38

Oh you just answered when I added a question to my posting.
Maybe the orange5 did the checksumming on the fly? Or was it literally editing a file and uploading it again?

dikidera · Post by **dikidera** » 02 Feb 2024, 10:30

Off topic but the lock cylinder on my Volvo s60 2005 is broken and I can remove the key from the steering column with the engine running. I have to try to lock it and see what happens.