P06B6 Diagnostic Tip

[forddieseldoctor]

I had a 2013 F350 chassis cab with the 6.2 in it that was setting a P06B6 for PCM knock sensor internal processor fault. The only pinpoint test steps listed in the pced is to reflash the PCM to the latest level, clear codes and if it comes back then replace the PCM. I looked at it initially and then one of my co-workers put the module in it. A week later it is back with the same code. Ended up finding the #7 coil arching intermittently between where the wire for the second plug attaches and the coil plug. But it never had a misfire. Replaced the coil and plug wire and the code did not return.

 

 

[cbriggs]

Interesting. Young guy in our shop was messing with one of these, that had knock sensor codes, and also 5 of 8 coils were arcing to ground. It got new plugs and 8 new coils. I never made the connection between that and the knock sensor codes. Customer denied any repair for knock sensor stuff, but it may be fixed anyways.

[Keith Browning]

I am beginning to run into more 6.2L trucks with  ignition concerns... and some older 6.8L too. A couple had odd codes and symptoms none of which were ignition related. Arcing is arcing and we know what happens there. Failing coils can cause serious RFI which can show up in weird ways.

I had a F350 that kept stalling. Only code anywhere was a P0500. I eventually looked at enough PIDS to see that when the stalling occurred the VSS went to 128 MPH just before, and at that time the engine load PID  took a nose dive and the engine stalled. Always at idle. Hot-Line suggested stress testing the coils which I did and I found ONE with an odd pattern on the scope. Replacing the coil took care of the concern.