Hi
Can someone tell me what this fuse is for and what voltage it reads to ground with switch on and off. I have CAN BUS comm problems and the car wont start (no spark) and this fuse shows 0V to ground. It also shows no resistance to ground so it may be shorted. i have nothing to compare too. I appreciate the help. My grandson needs his car.
Also will the fuel pressure sensor shut off the spark. I don't hear the fuel pump running. I could use a schematic too if anyone has one or a link.
Thank You in advance

 

CANBUS issue? how do you arrive at your diagnostic? Did you scanned it? Many sensors measure low resistance to ground eg: Air Flow sensor.
I don't have the wiring diagram, sorry but I did find this 2007 control schematic online, hope it helps.

 

Thanks for the quick reply!
CANBUS issues are suspected because of codes
P0084
P061b
U0101
U0121
U0155
I don't have much time on Mazdas but looks like a comunication issue. Car turns over but no spark. I did the Hi Lo resistance and got the 60 ohms.
Seems there should be voltage on the fuse marked ENG INJ . Any ideas would be appreciated.
Just tryin to save the grandson some money as I think a mechanic would drain his bank account with this one.

 

I would think so, when IG is switched ON in turn PCM sends a low voltage to IG MAIN RELAY point 347 and RELAY gets energized, fuel pump starts and also sends voltage to A/F sensor. Check IG relay or replace it and check PCM voltage swing. I'm basing this by reading this diagram but maybe it's different than yours.
EDIT: Check voltage PCM point 107 or fuse 02 ENGINE IG 15A in Fuse Block, I think is inside the cabin.

 

Thanks. Will do tomorrow. I think I checked them but will check again.

 

Well tonight I checked the IG and associated relays and all checked good. I had no spare main but I energized and contacts had good continuity with a meter. I also found that the Fuel Pump 25 amp fuse had no power to it no matter the state of the key switch. So that's no 12 volts on the ENG INJ and Fuel Pump fuses. I have checked every fuse and none are blown and they have 12 v on them. The O2 sensors were recently changed but it ran after they were changed. I'm stumped.
Going under the dash tomorrow and will plug and unplug some connections.