Truck stuck in limp mode

Check the IB1 connector behind the left kick panel, the pin for the fuel pump has been known to develop a bad connection there.

 

Alright, I'll cry if its that simple

 

That's for the 4.0 is the same as the 2.7?

 

Yes it is. I had an issue over the weekend and had to find the same connector.

 

4.0 and 2.7 use the same interior connector locations but I do see that 2010 has a slightly different connector layout so I posted the correct one.

 

Alright as soon as I get off I'm going in the parking lot and checking that

 

Update: I checked the connector and it felt loose but wasn't unclicked I unclicked it and re clicked it back in and it felt a little tighter, truck also didn't shut off as soon as I started it when I go home I'm gonna clear the codes and pray it is fixed

 

Just ran the code reader it now has different codes than before and all these codes correspond with the parts I replaced so is it possible the ECM is fried and is throwing all this junk? Codes are p0031 p0037 p0102 p0113 and p1613 first two say oxygen sensor heater control circuit low, 3rd is mass air flow circuit low, fourth is intake air temperature circuit high input and the final says secondary air injection system driver I'd just like to figure this out it's super annoying and yes I've tried clearing them.

 

Some things I’d look at just to eliminate possible causes.

You mentioned checked grounds. I’d also make sure the battery terminals are brushed clean and the posts too, they might be black with oxidation.

Test for coolant electrolysis. I’m guessing it’ll be in the pass zone.

Even though ground is good, try putting jumper cables from the negative battery terminal to the block. Clear codes & see what happens.

Do you see any symptoms of rodents? Footprints or nesting material.

I’m not at all saying these suggestions are going to fix anything. It’s just some of the oddball things I would do with the oddball symptoms you have.

 

I actually also replaced both battery clams should've mentioned that how do I check the coolant for that and this truck is spotless and driven daily, no rats here

 

Alright I've finally got around to testing it, it said 43 constantly now to be fair that is 1.5 above regular and it says to replace the regulator if too high but is it possible my gauge is slightly off considering its Amazon or should I just buy a regulator to be safe and if it isn't the regulator what's my next move, ecm I'm assuming since it's the only thing left I'd assume would throw all these codes

 

43 psi is pretty common you are fine there.

 

Yea I wouldn't worry about a couple psi with the symptoms your experiencing, the main thing is you don't want to see a significant drop in fuel pressure when the engine is under load or acting up. If fuel pressure is holding steady right at the correct pressure when the truck is running bad then fuel pressure isn't your issue.

 

So you fiddled with a connector and changed the situation. I'd chase that down a little. I personally hate connectors. Scourges of the earth. I'd spray some contact cleaner in there and add a dab of di-electric grease for good measure.

 

So it didn't really change it like I thought I believe I was being hopeful and thought it made a difference, I do know as soon as the throttle blade say 24% anymore and it forces it back down around 7 or 8%

 

Should I just replace the ecm and hope that it fixes it? To be honest I'm not sure what else there could be to this problem

 

I'm pretty sure if your coolant is pink, it'll pass electrolysis test.

What I do is with the engine cold, remove radiator cap. Multimeter set to dc volts. Connect negative lead to negative battery post. Positive lead I clip to a copper cable lug, dunk the lug in the coolant. I read somewhere .4v or more is bad. This is saying .3v.

https://www.northernradiator.com/knowledge/Electrolysis

A new ecm isn't gonna be cheap.

 

Yeah I know a new ecm won't be cheap but if I could make sure it would be my fix I can get one from a reputable source that's plug and play for 350 or 400 around there

 

If it does have electrolysis or whatever I would know it's a ground? I just think it could be ecm just because the effect of limp mode was instant and not intermittent or randomly happening just truck shut off and started doing this after startup, not denouncing a bad ground but it's so confusing to me how it throws all these codes for a bad ground

 

Ok so I did the test but I'm having issues with my voltmeter I'm not entirely sure I'm even on the right setting but I played around and it's possibly .1 V I don't know if that's too low or I'm just not reading the correct setting it's confusing because there's so many setting on it and it's not clear on which one is which