There is an IPDM self test you can perform. It cycles all of the relays in the IPDM with the engine off to verify they work. If the ECM relay is bad, you can test by swapping the fog light relay. I think it is only recommended for testing and not a long term solution if the ECM relay is bad as they may not be exactly the same. I replaced my ECM relay with the updated part from Nissan years ago- it was only about $5 online.
I stand corrected. Looking up that newer style IPDM and there isn't a relay listed, so it looks like you are correct in that the entire IPDM would need to be replaced. I found a video on youtube for a Titan with the same IPDM and he removed the back cover and found some burnt traces on the circuit board. He had to replace the entire IPDM.
Checked all connections fuses relays and all are good. No power coming from e119 e120 or e121 out of the ipdm or at the ecm.
Plan on buying a new ipdm and if still nothing ig I’ll buy a new ecm. I’ll update as I make progress!
Yes when I pull relay to fans it turns fans off and literally everything else on car works besides no start, obd port don’t link (has power) looks like anti theft light stays on but doesn’t explain the obd port issue
Does the anti theft stay on when you try to start it?
If system detects malfunction, security indicator illuminates when ignition switch is turned to ON position.
Possible symptom of NATS malfunction is “Engine cannot start”. Identify the possible causes according to “Work Flow”, Refer to SEC-5, "Work Flow".
Now that you mention the anti theft, that's another thing that should be eliminated as a possible cause. I would also double check all fuses, including interior. While you are doing that, it couldn't hurt to disconnect the battery in an attempt to perhaps reset one of the computer modules. Can you verify your OBD reader works on another vehicle?
Did you try disconnecting the battery for a while?
Here is a thread for a Titan with a similar no-start issue. A couple people posted a solution from a Nissan manual to reset the immobilizer. You can try that.
Does anybody know the proper sequence to reset the vehicle immobilizer on a 2005? Long story short, I was self installing a remote start and did not have the immobilizer portion of the T-harness all the way seated into the immobilizer on my first start up, now my truck will just crank, no...