OBD II no communication with scanner

[stevemccann180]

I have a high end OTC Genisys touch scanner, it wont communicate with my 02 xlt 4.6 4x4. i checked the terminal for proper ground and readings as far as resistance is concerned. all checked out ok. looking under the dash, there are a lot of splices for towing as well as an aftermarket alarm system that is unlugged. should i just yank the dash and repair the wiring harness or is there something else i should check first?

 

[D Hook]

If all that checked out okay, I would test the scanner first on another vehicle to be sure it's not something in the scanner.

 

[stevemccann180]

yes

I have used the scanner successfully on several other vehicles.

 

[Number4]

The positive line at the connector is hot?

 

[stevemccann180]

which line ? orange?

 

[Number4]

White/Yellow should be hot at all times.
Orange is UBP Diagnostics
Black, Black/White are ground

Tan/Yellow is Can bus +
Red/Yellow is Can bus -
Both of these are frequency dependent. They shut down when tapped in my experience.

Violet is module programming signal
Light blue/White is data bus ISO 9141 (k-line)

 

[JK080]

I have a high end OTC Genisys touch scanner, it wont communicate with my 02 xlt 4.6 4x4. i checked the terminal for proper ground and readings as far as resistance is concerned. all checked out ok. looking under the dash, there are a lot of splices for towing as well as an aftermarket alarm system that is unlugged. should i just yank the dash and repair the wiring harness or is there something else i should check first?

Check the cigarette lighter fuse, most of the time the power circuit for the OBD2 connector is on the same circuit.

 

[doug625]

I have a high end OTC Genisys touch scanner, it wont communicate with my 02 xlt 4.6 4x4. i checked the terminal for proper ground and readings as far as resistance is concerned. all checked out ok. looking under the dash, there are a lot of splices for towing as well as an aftermarket alarm system that is unlugged. should i just yank the dash and repair the wiring harness or is there something else i should check first?

Ever find out what the issue was? I'm having the same problem, cigarette lighter works, no blown fuses but 3 different readers won't get anything from it.

 

[stevemccann180]

If all that checked out okay, I would test the scanner first on another vehicle to be sure it's not something in the scanner.

 

[stevemccann180]

Scanner is ok