Re:2017 Titan 5.6 P0101

Used car lot down the street got this canadian gem in it is kicking my butt. Also throws c1130, which a bullet states to address other codes first on. P0101 is maf sen circ but could be nearly anything on these.

Dtc sets as soon as it is warmed up. traction light comes on and it is in limp mode. It came in with no air filter, so I put one in thinking that was going to really be all it needed. I found this orange powdery residue on the intake boot and thought maybe the maf was contaminated so I replaced that and cleaned the throttle body. Maybe dried rusty water? Looks like there was a lot of poking at the sensor and a repair near the connector so I replaced the connector and redid the wire repair. Fuel trims are good, no air leaks. Has good power. Monitored rear o2 during wide open run and stayed rich with no drop outs. Not sure where to go from here. It's so easy to reproduce that I thought I'd be able to see something in the data, but I see nothing abnormal. Sets when it warms up, never fail. You can hear the high idle kick in if you're outside of it. Once in limp mode it's tough to do any tests because all of the numbers are wacky.

No history at all on it. The dealer says that's how they got it and all they tried was an aftermarket maf. Wondering how long it was run with no air filter and what the deal is with that orange stuff? Our techline wants me to try running an alternative fuel and replace the pcv valve. I'm not convinced that either of those are the issue though. I'm going to take the throttle body off again tomorrow and take a look at it. Open to any thoughts!

Nissan Technician

I don't know if it'll help, or not. But, All-data refers to ABS.

You know, I am going to look at that code tomorrow. Our techline wants me to stay focused on the p0101, referring to the bulletin that says to address those codes before this one, but this one makes more sense to me. I've never seen a Nissan go into limp mode from a p0101 and it's gotta be one of our most common dtcs. I've also never seen both of these set together consistently like this. I feel like I should at least should rule it out at this point. Thanks, Chad.

Nissan Technician

Official position does appear to be address P codes first.

static.nhtsa.gov/odi/tsbs/2016/MC-10119282-9999.pdf

Apparently a problem with the EVAP pressure sensor can set a P0101 :blink: Might be worth monitoring EVAP PIDs to see if anything happens there when the codes set.

Yes, that reminds me to check that because the share a circuit. Thanks, doing that now.

Nissan Technician

Nope, all good there.

Nissan Technician

One car i was dealing with a while back had a maf code but it was a iac having a hiss fit. Probably would be a good idea to hook scope leads up to the iac and see if it shows any thing. Otherwise was any debis in the intake or stuck at throttle plate or iac?

I didn't really get to mess with it today besides checking the vent valve circuit. These don't have an iac and I did try doing a TB sweep test but this was the first vehicle I've seen that that didn't work on. Plate was fixed at like .750 at both TPS KOEO. Both APP sensors appeared good though. I do have a known good TB on my toolbox that I am going to throw on for the hell of it.

Nissan Technician

That was the first thing I did this morning and it still didn't work. I tried this last time it was here and couldn't do it then either. Is it a clue or maybe model specific? I saw that the throttle relay was on too.

Nissan Technician

I considered the cats after having a sentra in last week with p0101 and stuffed converters after putting six gallons of diesel in it last year and not replacing any parts. It seems to have power and alphas appear normal on both banks, but if I don't get anywhere with the throttle body I might plug in the back pressure tool and see.

Nissan Technician

I replaced the throttle body and updated the ECM and its fixed now. I let it idle for about. half hour then took it for an extended test drive with no issues.

I tried doing a TB sweep test again after clearing codes and they were still stuck at 750mv so I checked SI to see what is expected KOEL and found that the truck has to be in drive to get a response there. It did work but I didn't find anything odd there.

Not sure exactly what the problem was and don't usually run off hunches like that but I got lucky.

Nissan Technician

Sorry I missed out on this one. Still glad to hear you got it fixed!

Between the throttle body and the ECM update, which one do you believe had more to do with the fix? Asking because it's my understanding that the P0101 code has more to do with the reported airflow rate (from the MAF) compared to what the ECM expects at that RPM/throttle opening. It's always been my guess that the update just widens the expected airflow rate.

But, I suppose it's also possible that the throttle body you replaced on your Titan was flowing the incorrect amount of air, resulting in the same problem. Bore wasn't the right diameter, creating turbulence, like that. Did the throttle body appear to be original?

Thanks! My guess is the throttle body. I am not sure what the updates addresses on these. I'll take a look in a bit and see if I can tell. Maybe I just didn't do a good job cleaning it the first time? My (possibly far fetched) theory - after cleaning you are supposed to a couple of relearns and the air volume one wouldn't go through because of whatever the issue was. The vehicle has to be at least 70*c for it to work and I couldn't get it there. Part of the ECM update process ends by going through all of the learning and it did go through after the new TB. Maybe some of whatever that orange stuff in the boot was got in there?

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Sounds logical to me!

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