Injector Control Circuit Codes

[SKB]

Long time listener, first time caller.

I just bought a used 2020 2 weeks ago that has 18k miles on the clock. I checked all the recalls, as many fluids as I could access, and the OBD2 for any pending codes. Drove it for just over a week and I started getting an intermittent rough idle. It only happens at startup and if I keep the RPMs at 1,000 or more, it doesn't happen.

If I let it sputter and hesitate, I get all 6 injector control circuit codes. Now the PCM is showing historic faults on all 6 and if I clear the codes it shows a pending fault on all 6. It's sitting at the dealer now, where I have a friend with a friend's who are mechanics there who should help look after it. Anyone have these problems or any ideas? I'm leaning toward a harnesa or ECM issue since it's an electrical fault code and not a mechanical related code, but it's a computer basing diagnosis on preprogrammed faults specified by an engineer's FMEA.

Plugs look fine, connections look fine, harness crimps at the PCM connection in the engine bay look fine. It's been quite aggravating.

 

[B E N]

All 6 share a common ground power (see post #4) within the harness. Chances are that ground is janky somewhere.

 

[CoronaRaptor]

Welcome to the place. Congrats on your Gen 2, keep us posted what they end up finding out.

 

[FordTechOne]

Those DTCs are for the port fuel injectors. The port injectors all share a common power circuit and are grounded individually by the PCM to actuate. Chances are there is an open in circuit CBK01, most common cause is rodent damage.

 

[SKB]

Now I wish I would've done this before dropping it off at the dealer, who still hasn't looked at it. All the 'Rona backlogs catching up, I guess. I'll let you guys know what they find. I did not see any evidence of harness damage from the connection on the firewall to the engine, but I also didn't check the wires in the cab behind the gloves.

This is also a good lesson. The dealer I bought the vehicle from is about 70 miles away. They would've got me in right away, but I wasn't sure if it would make it all the way down there or if I could make it back. So, it's at the dealer I bought 2 other vehicles from, but it's not getting prioritized like if I had bought this one there. All I can do is call a couple times a day and try to be nice so I'm not subjected to vindictive delays.

 

[Mountain Man]

Had same codes and the dealer had to replace the wiring harness for the fuel injection system. Thank God for ESP as it was an expensive repair and not covered under warranty

 

[SKB]

Sounds like they suspect PCM damage. My friend's friend who is a mechanic there has been checking up on it for me because the service writer is fairly unresponsive. He asked if it ever had an aftermarket tune on it, which it never has. I found the 1st owner, who is a 68 yr old retired pastor, and he said it never did.

How likely do you guys think it is that they will try to make it look like something that voids the warranty? If I did a bunch of hard resets on the PCM because that the only way I could get it to start, would that reflash the PCM and make it look like someone was messing with it?

 

[SKB]

It was the injector wire harness. No rodent damage, just a bad wire. They replaced the entire harness just like Mountain Man said they did on his.