Son has a 2006 Maxima. He’s had it several years and is very good on maintenance. Went out the other morning and it would not start. Checked the fuses, swapped relays, etc and no change. He can hear the fuel pump running when key on. Security light turns off while cranking. Connections and grounds all seem to be fine. Good continuity between negative bar post and engine. Ran codes and getting a U1000, no CAN communication. This one has me stumped and I’m looking for assistance.

 

Check crank position sensor.