factionos Posted May 9, 2015 Report Share Posted May 9, 2015 (edited) So our Edge has only really had a few problems (brake booster cylinder, random airbag code we can't find) But now its gotten really bad, about 2 weeks ago upon start up it started intermittently idling rough and driving poorly, the next time it was started it ran fine, then again it ran rough and finally the check engine came on. I got the codes for P0203 - Injector circuit / open cylinder #3 I thought that testing the #3 injector would be the first thing to check, I switched the #3 and #4 injectors and nothing changed. This leads me to believe the injector itself isn't the problem but perhaps the wiring? Has anyone had experience with this? Edited May 10, 2015 by factionos Quote Link to comment Share on other sites More sharing options...
WWWPerfA_ZN0W Posted May 9, 2015 Report Share Posted May 9, 2015 (edited) Well, you disproved the most obvious reason: injector fault. So on to the wiring. http://www.obd-codes.com/p0203 Have you had the intake manifold off before? Could be pinched wiring. Ideally you would check the wiring for continuity/resistance between the PCM connector and the FI connector (all 6 of them for comparison). Injector (INJ) Connector Vehicle Connector Pin Circuit A 1 INJ 2 VPWR PCM Connector Edge, 190 Pin E52 INJ1F-150 4.2L, E53 INJ2MKX E54 INJ3 E55 INJ4 E56 INJ5 E57 INJ6 Edited May 9, 2015 by WWWPerfA_ZN0W Quote Link to comment Share on other sites More sharing options...
factionos Posted May 9, 2015 Author Report Share Posted May 9, 2015 Well, you disproved the most obvious reason: injector fault. So on to the wiring. http://www.obd-codes.com/p0203 Have you had the intake manifold off before? Could be pinched wiring. Ideally you would check the wiring for continuity/resistance between the PCM connector and the FI connector (all 6 of them for comparison). Injector (INJ) Connector Vehicle Connector Pin Circuit A 1 INJ 2 VPWR PCM Connector Edge, 190 Pin E52 INJ1 F-150 4.2L, E53 INJ2 MKX E54 INJ3 E55 INJ4 E56 INJ5 E57 INJ6 Hmm this was the first time I have had intake manifold off (we had the brake booster replaced about a year ago so its possible they may have removed it in the past during that repair) I am happy to try and trace the wiring at this point, do you happen to have a diagram of the PCM pin locations? I appreciate you listing them out I just need to know where to trace Quote Link to comment Share on other sites More sharing options...
factionos Posted May 10, 2015 Author Report Share Posted May 10, 2015 Update, so I removed the intake manifold and did a couple things to determine if the spark plug or coil where part of the issue. switched the #3 spark plug with #1 switched coil pack from #2 and #3 neither had any effect and still had the same DTC of P0203 at that point I put everything back together with #3 injector unplugged, I started the car and checked the voltage and it was the same as the other cylinders I checked. I then plugged the injector harness back in and #3 started back up and its running fine now. I have no idea what is going on at this point... Quote Link to comment Share on other sites More sharing options...
factionos Posted May 12, 2015 Author Report Share Posted May 12, 2015 Tonight i wired in a replacement plug for #3 injector, unfortunately it did not fix the issue and i am still getting an open condition on #3 I'm starting to think its the PCM at this point, I really want to try and trace the wires for #3 back to the harness but everything is so tightly wrapped i am not sure what to do. Quote MultiQuote Edit Quote Link to comment Share on other sites More sharing options...
WWWPerfA_ZN0W Posted May 12, 2015 Report Share Posted May 12, 2015 Hope this PCM connector diagram helps: 3-5L 4V Edge-MKX 140 pin PCM Harness Connector.PDF Quote Link to comment Share on other sites More sharing options...
factionos Posted May 12, 2015 Author Report Share Posted May 12, 2015 Hope this PCM connector diagram helps: 3-5L 4V Edge-MKX 140 pin PCM Harness Connector.PDF you are awesome! thank you for getting the diagram. now i just need to figure out if the PCM is the issue or a bad connection/wire Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.