IMEI update issue

[Evluma]

Hello and thank you for your help

I am working with the 9151 Rev3 and I attempted to update the IMEI with a valid one provided to us by Nordic

But the following error occurred

*** Booting nRF Connect SDK v2.9.0-7787b2649840 ***
*** Using Zephyr OS v3.7.99-1f8f3dc29142 ***
The AT host sample started
Ready
> at+cgsn
359404230716624
OK
> at+cgsn=1
+CGSN: "359404230716624"
OK
> AT%IMEIWRITE=0,"358757450008449"
%IMEIWRITE: 000000000000000
OK
> at+cgsn=1
+CGSN: "359404230716624"
OK

The command documentation states that if the IMEI is locked and cannot be updated, AT%IMEIWRITE, that the returned result will be the locked IMEI but in this case

it is returning "000000000000000" instead of "359404230716624"(factory default) or "358757450008449"(desired IMEI)

this same result was generated while using PTI 2.3.3 and PTI.2.3.6

thanks

[dejans]

Hi,

How many times have you tried to write IMEI?
nRF91x1 production test AT command guide specifies that nRF9151 LACA A0 module includes a default
IMEI that can be changed once. 

Please find below a caution note.
CAUTION: The command is a one-time operation. When the modem has been activated or the
%IMEIWRITE command has been given once, the command cannot be used anymore. The device
can become unusable if the wrong IMEI is written.

Best regards,
Dejan

[Evluma]

Evluma said:

it is returning "000000000000000" instead of "359404230716624"(factory default) or "358757450008449"(desired IMEI)

The "359404230716624" is the default loaded IMEI and I tried to write the IMEI "358757450008449". This is not a case of multiple writes of an IMEI.

I am not sure why it is returning "000000000000000", while the documentation states it will return the stored IMEI regardless of success or failure of an IMEI update via %IMEIWRITE.

Cheers

Warren

[dejans]

Hi Warren,

Which IMEI is read with imei-read? 

Best regards,
Dejan

[Vahram]

Hey there!

I'm not sure if you're still experiencing this issue, but on my nRF9151 board, I had the same behavior. It appears that the first time we wrote 0x0 as an IMEI address. Note that the 0x0 can come up because of doing something like 'atoi("non-imei-string")'.

With 'nrfutil 91 imei-read' command it returned following:

```
slot 0: <factory default>
slot 1: 000000000000000
```


The chip doesn't seem to have any safety mechanism to prevent this from happening, so I think that's what we have.
I hope there is a method to force the board to use its default IMEI so that it can still connect to LTE. Still, I haven't found anything like that yet.

Hope this helps somebody :)

Best,
Vahram

[dejans]

Hi,

Evluma Did you manage to resolve the issue? Can you provide an update?

Evluma said:

I am not sure why it is returning "000000000000000", while the documentation states it will return the stored IMEI regardless of success or failure of an IMEI update via %IMEIWRITE.

Did you get all zeros as output from imei-read? Can you show the result?

Vahram said:

The chip doesn't seem to have any safety mechanism to prevent this from happening, so I think that's what we have.
I hope there is a method to force the board to use its default IMEI so that it can still connect to LTE. Still, I haven't found anything like that yet.

Vahram Has your issue been resolved? Has your device been able to connect to LTE network? Can you provide an update on current status?

Best regards,
Dejan