I bought my 2015 F250 6.2 V8 in Jan 2020 with 62k miles and a week or two after I got it the check engine light came on and I got the P06B6 code. Odb-codes says, "it means that the powertrain control module (PCM) has detected an internal processor performance error with a certain knock sensor (designated 1) circuit."

My mechanic said it wasn't knocking so he cleared the code and said to see if it comes back. I didn't drive it much last year working from home, but the code finally came back. Went back to the mechanic and he said the PCM needs to be re-flashed or replaced at the dealer. Dealer said my #8 lower plug was broken and replaced the coil, wire, and plug and said if the code comes back the next step is to replace the PCM and quoted me $1200, all my warranties are expired.

Everything I've read online points to coil arcing being the cause of most P06B6 codes, and that the PCM rarely needs replacing. I'm going to replace the plugs and wires this weekend, and inspect the coils for corrosion while I'm at it, but I'm not really sure if I I'll be able to tell for sure if a coil should be replaced or not without seeing an arc or actual physical damage.

I'm afraid that if I pay the $1200 to replace the PCM the code might come back because of a coil, so I was thinking about replacing the rest of the 7 coils which would cost me about $650. Then again I'm afraid if I replace the coils the issue could really be the PCM. Should I flip a coin?

I also tried testing the bad coil the dealer left me with a multimeter but I can't find the resistance specs online or in my Haynes manual. I was a little skeptical that it needed replacing since it didn't have any signs of corrosion, but I can't tell for sure if it's bad.

 

I had the same code. I found a plug arching and replaced the coil. The code continued. When connecting my trailer electrical connector, I had no tail lights or brake lights. I looked under the truck and my wires to my plug in were all corroded and some not attached. I had ford garage repair the connector and the code p06b6 never returned. That repair corrected my problem. the repair was done over a year ago. Hope this Helps.

 

That's super interesting because the previous owner had scraped the tow harness and the mounting bracket on the ground and the cover had broken off. The contacts were all corroded and would get water in them so I just replaced it with a new harness and bracket. I'll try clearing the code, hopefully that was the issue. Thanks!

 

IF you have coil arch, you need to hear the arcing first to determine which coil is arcing. In my case I got lucky and coil for Cyl #1 was arcing. However prior to that, Ford replaced the PCM under warranty when the code first popped up again after several months of no codes. I came across a 6.2 Superduty troubleshooting video that showed coil arcing. Sure enough I found the problem. As for the 7 pin, I don't know what that might have to do with that particular code. The only thing I can think of it has to do with a grounding condition. However I am shocked the dealer went ahead and replaced the PCM without performing additional troubleshooting for the real problem.

 

I started replacing the spark plugs and inspecting the coils and a few of them are pretty heavily corroded. I'm just going to replace all the coils so I'll be able to eliminate that as a possible cause.

 

Use one of the larger on line Ford parts departments like White Bear Lake Ford in Minnesota or Tasca Ford Rhode Island are just two of them. However they got good pricing on the OEM parts. When I priced out replacing all 8 coils it was around 800 bucks for the everything. However I knew coil #1 was arcing since I saw and heard it. Good luck with your repair.

 

I ended up replacing the remaining 7 coils, wires, and 15 spark plugs, and about 800 miles later the code hasn't returned. Looks like it was the coils. Glad I didn't let Ford replace the PCM.

 

some vids about coil corrosion....