Hi All, driving down the highway, my truck suddenly lost power and started running like an old tractor. Codes P0203 and P2149 came up. I still carry an ice pick just in case, but this time, to no avail. Towed it back home to diagnose. I pulled the FICM connectors and ohmed out CYL 3 injector harness, looked for any chaffing (I corrected all of the chafe points 18k miles ago during my complete build) and it came back ok. I ordered and replaced the cylinder #3 connector just in case since it had been picked years ago. Hooked everything back up, cleared the codes. Truck starts, runs about 10 seconds normal then instantly throws P0203 and P2149. I do have a random UNK1000 code but have been chasing that over a year - not sure if related. SO Pulled CYL 3 injector and sent to Lincoln for testing. I completely expected that 100% over reman to have an issue, but they just called and said the injector is fine! Back to the drawing board. Harness is good, injector is good. Is there a way I can test the injector with the harness connected? I doubt the new connector has issues but I'd like to check anyways. FICM is known to have issues and could be it, but considering it runs fine for 10-20 seconds, I was thinking that isn't it. Any ideas or recommends before I start messing with the FICM?
LLY Limp mode - P0203 and P2149
- Thread starter NevadaLLY
- Start date
Mine isn't tied to the alternator bracket since the build in 21. Either way, I still opened up the loom and looked for any rubbing. No damage I can tell. I ohmed from FICM connector to the injector #3 connector while disconnected and wiggled the harness like crazy. Bent it, moved it, pulled it and on both wires was about 1 ohm.
A better test is to measure from the ECM connector through the harness and injector all at once. May be worth using an LCR meter too. The resistance is too low to accurately measure the injector and harness with a regular ohm meter. A short can still show as 1 ohm which won't look abnormal. But with an LCR meter you should see close to 120 mH and will be much less with a short.
But a regular ohm meter will be useful for shorts to ground or other injector wires. As the resistance should be infinite
Keeping the harness connected to the injector will also test the connection there which as you are likely aware is a potential problem. But might be worth closely inspecting the ECM connections for that injector too
But a regular ohm meter will be useful for shorts to ground or other injector wires. As the resistance should be infinite
Keeping the harness connected to the injector will also test the connection there which as you are likely aware is a potential problem. But might be worth closely inspecting the ECM connections for that injector too
I didn't realize I could test from the ECM to the injector - I thought it started at the FICM. Which pins on the ECM tie to which injectors? I can follow a wiring diagram but mechanical parts are my strong suit
My bad. You are right. I was thinking LBZ. So yeah. Change all mentions of ECM to FICMI didn't realize I could test from the ECM to the injector - I thought it started at the FICM. Which pins on the ECM tie to which injectors? I can follow a wiring diagram but mechanical parts are my strong suit
No problem - Do you happen to know what the readings should be with the injector connected? I assume testing is now back at the FICM for both wires since the connection is made at the injector.
I mentioned it above. About 120 mH with an inductance tester (LCR meter) and no more then a few ohms depending on the sensitivity of your ohm meter. Shouldn't get any resistance when checking to ground or shorts to other wires unless it's part of the same injector bank. So measure accordingly.
Ok - SO check my schematic skills. Since I'm only throwing P0203 and P2149 - it means only injector 3 is the problem and P2149 means that bank is shutting down. To me, this means FICM pin 118 (injector supply voltage) is OK. If it was on that side of the injector, I'd get P0202, P0203, P0205, P0208 as well as P2149. Means supply voltage is OK from FICM but being shut down by P2149.
So next, I'm searching for an issue between FICM 115 and fuel injector 3 (which I've already tested is good). BUT what I haven't tested is ECM 52 to FICM 47. If I have a short/disconnect there, that could also throw P0203 as the control side would be down. Do you agree? Or am I completely wrong.
I wouldn't assume any of the wires are good. 118 to injector #3 could be bad. You should load test the wires to make sure it's not a loose, barely touching or corroded connection/wire. Be careful if you load test through the injector at the same time. Keep it brief and current at no more then a few amps or risk burning the solenoid.
The issue is on the FICM to injector side and not ECM to FICM. There are separate codes for bad control lines. Worse case is a bad FICM. But you better rule out the harness first as they are not cheap and the aftermarket alternative is not ready yet
The issue is on the FICM to injector side and not ECM to FICM. There are separate codes for bad control lines. Worse case is a bad FICM. But you better rule out the harness first as they are not cheap and the aftermarket alternative is not ready yet
Yeah I already checked 118 as well - just trying to narrow it down. Doubt there's anyone around here I can swap FICM's with to check.
I wish! I’m in Reno so not that far, but timing sucks. I need this thing back up by Aug 15 and travel a lot for work.
Ok injector is back from LD and installed. Of course same issue. For the heck of it, I ice picked the new connector. I ohmed from ECM to ficm - wires are good. Ohmed from FICM to injector 3 - shows good. I can’t do the inductance test but LD proves the injector is good. Still throwing P0203 and P2149. I pulled and chased wires, shook everything while truck is running and no change.
Is there any way to test the FCIM? Also, has anyone had wires ohm out less than 1 but still have a short? If it is a short, I think if I moved the wire, the short would resolve and the bank would resume or does the code have to be cleared first and short removed? Not sure on that one.
I think you are at the point of bench testing the FICM or swap test with someone else's. If you want to bring your FICM down to me and test it in my truck you are welcome. Don't know if there is anyone else closer that has a working FICM
Is there a sticky for bench testing - I’ve pulled the FICM. Everything else testing good, has to be it right!?
Not really. There are a number of posts, mostly in the LLY FICM and the twins with twins thread where we talk briefly about it. Basically you need a set of injectors, or at least the solenoids from them. A connector to plug the FICM into. Pigtails for the injectors and the ECM with the minimum number of sensors, throttle etc or an emulator like I and Kidturbo use. And a power supply
This is how I set mine up. Not complete here but should give you an idea.
Most aren't going to go through the effort to build one for a single test. More effective or cheaper to find someone you can swap with. You can always try SIA to see if they can test and repair if needed. Otherwise you can bring it to me and I'll test it in mine. Your choice