I have a friend with a 2009 Mitsubishi Outlander, he can't seem to get it to start and the only error code he got was P1637.
It seems to crank fine, he can smell there's gas, he swapped the battery also but there's just no spark.

We reset the DTC and tried restarting again and the error code re-appeared.
I'm trying to determine if this is an issue with the ECU or a mechanical issue.

If it's the ECU I don't know if that also means new keys etc.
Checked the relays and fuses, they seem to be OK

Any help appreciated.