Hey guys so I have a 07 F150 5.4L it has been driving fine but i have noticed some rough idles when sitting.... I left work on friday truck was driving fine went to menards came out 20 mins later truck fired up sat idle then turned off and wouldn't restart. When I would go to turn the key all it did was (tick).....so I have now replaced the battery and starter in menards parking lot, it wants to turn over but is not firing so I checked fuses and my lighter/diagnostic fuse was blown. I replaced the fuse and drove to my shop (autobody not mechanic) and grabbed our scanner hooked it up and it says (failed) to find the vehicle. I even manually punched in the make year and VIN and it still came up failed and unable to scan....so I am guessing its not finding the computer but why? ANYONE have any answers or suggestions it would be appreciated! this sucks lol
- Sean

 

Possible reasons;
No voltage at the DTC port to power the Scanner.
Bent or pushed DTC connector pin.
The OBDII Scanner not able to work on a CAM system that came in after 2004. Use correct Scanner.
A fuse is still blown that feeds the PCM or DTC connector.
If the motors starts but the Scanner cannot connect, it has to be one of the above.
If there is no CEL lamp don't spend any more time because you likely won't see any code other than normal diagnostics being processed until they are completed without a fault being detected.
Good luck.