Need help identifying crystal

[jons]

Got VW Bosch ECU with rotted away crystal oscillator and can't find frequency for it, it drives Bosch 30302 chip for which there is also no any datasheet. Markings on it says
453NDK9X.
and there is nothing on internets about it that I can find.

[truclacicr]

453 = 45 x 10^3 kHz = 45 MHz ???

FWIW, NDK is a manufacturer of automotive grade crystals.

https://www.ndk.com/en/products/sear...B8%AF%EF%BC%89

[richnormand]

If you cannot find information on this xtal you might consider using a simple ring oscillator to see the frequency.
Or a square wave signal generator and a scope to look at the ringing frequency.

[harp]

"453 = 45 x 10^3 kHz = 45 MHz ???" Guess not that type decoded acording attach... maybe to search datasheet of ic for what is connected to crystal...

[R_J]

Looks like it just broke away from the board, likely poor solder, you could try removing the board and reinstall and resolder it

Look at the other crystal... 447NDK9X, I suspect they are custom numbers

[richnormand]

If you cannot find information on this xtal you might consider using a simple ring oscillator to see the frequency.
Or a square wave signal generator and a scope to look at the ringing frequency.

Is there enough contact left so you can solder a pigtail or probe the xtal? If so can you put it back in circuit? If not, can you contact it to make it oscillate in a test circuit?
If you can determine the frequency a substitute could be found in the same form factor.

I assume the microprocessor is also a house number? If not you could ballpark the frequency from the spec sheet.

Was it corrosion or something else that happened? The board looks clean overall from your photo.

Do you have access to a scope, spectrum analyser, signal generator?
Can you protoboard a simple ring oscillator (TTL CMOS inverters) and such to get it going and measure the frequency?
Knowing that would help to give you more info to reverse engineer the issue.

Cheers and best of luck.

[jons]

Legs ar corroded off although otherwise board is quite clean. No scope fast enough unfortunately, I think it must be in tens of Mhz, and microprocessor is Bosch 30302 as I wrote so this also is dead end. Looks to me that most realistic way is to bodge some wires to it which I've done and ECU starts, car still not running but that to my mech. Not the most reliable repair to my liking but it's at least something.
Thanks all for suggestions.

[truclacicr]

442NDK = 4MHz
443NDK = 6MHz
444NDK = 8MHz
445NDK = 10MHz
446NDK = 12MHz
447NDK = 16MHz
...
453NDK = 28MHz ??? (unless the "5" is not part of the arithmetic progression)

Edit:

NDK W-191-451 is a 26MHz crystal, so 453 looks like 30MHz ???