2016 sierra maf wiring

[1SLOW1500]

My maf is giving some codes and I can't seem to fix it. 

Bought a new Maf but still not working. I also checked all wires and seem good. 

Please help is there a fuse?

I can post codes if needed. 

If I can get the pin outs I can at least meter each wire and see where it is missing. 

Thanks......

[Jsdirt]

If you're under 36,000 miles, make GM fix THEIR problem.

 

If you're over your warranty miles ...

 

Most GM MAFs today have 5 wires, since they incorporate the IAT sensor these days. There's only 3 for the MAF itself: power, ground, and a signal wire - you'll need a multimeter that reads Hertz (Hz) (signal output) in order to properly diagnose an issue .

 

But before you go crazy, if you're running an air filter that requires oil, clean the MAF first, and throw that filter in the trash.

[Jsdirt]

I would do some more testing before condemning the ECM - that's the last step of the process, since you'll have to have it programmed by a competent shop (not the dealer) in order for it to work. Good chance that's not the issue.

 

This to me is screaming a wiring problem - might not even be related to the MAF wiring. Could be an intermittent fault in the 5v ref, ground, or power either to a sensor, or to the ECM. Lots of possibilities, and condemning the ECM is the LAST step in a long process. 

 

Would be cheaper for you to buy a subscription to Identifix, Mitchell, or Alldata in the long run. Firing the parts cannon at a problem never ends well for your wallet ...

[1SLOW1500]

I think you are right however I think the issue is at the ECM connector. Now that I have all the wiring pin outs and diagrams I can re meter the wires and even check at the ecm. All the wiring up top is good and If I meter at the MAF I get a ground and a 5v, the other wires are in the milli amp range. 

I will ohm or continuity check the wires to the ECM connector pin 

[Jsdirt]

Don't waste your time with resistance checks. You need to test those wires with a real load on them - like a halogen headlamp. If it can't power the headlamp, it can't power the circuit. Resistance tests never load the circuit enough to reveal an issue. You could have ONE strand of wire hanging on, and the resistance check will be good every time - put a real load on that same circuit (or do a voltage drop test, with the circuit loaded of course), and the problem will reveal itself. 

 

Of course, you'll want to isolate the circuit your testing before applying power ...

[1SLOW1500]

Don't waste your time with resistance checks. You need to test those wires with a real load on them - like a halogen headlamp. If it can't power the headlamp, it can't power the circuit. Resistance tests never load the circuit enough to reveal an issue. You could have ONE strand of wire hanging on, and the resistance check will be good every time - put a real load on that same circuit (or do a voltage drop test, with the circuit loaded of course), and the problem will reveal itself. 
 
Of course, you'll want to isolate the circuit your testing before applying power ...

Interesting so with sensor plugged in? I can't start the truck. It starts and shuts down. It was always doing this but now it is different I can't get past it.

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[Jsdirt]

Yes, you can back probe the sensors while they are still plugged in to check sensor operation ... but in order to test the wiring you need to disconnect the circuit from it's origin (ECU), to whatever sensor it goes to, and apply power and ground at one end, with a 4-5A test bulb on the other.

 

I didn't realize this was a no-start. That changes everything. Got to start with the basics here - fuel, air, spark, compression. Fuel pressure test first, then proceed with the rest.

[1SLOW1500]

Truck has 6700 miles on it but it is also a single turbo now so I would say GM will not care for that. I installed a new maf and still same issues. I can use my digital meter on it but without a pin out diagram I would be guessing. It is a 8 pin. Is there a Fuse?

0x7E8: P0036 - HO2S Heater Control Circuit (Bank 1, Sensor 2) (Permanent)

0x7E8: P0097 - Intake Air Temperature Sensor 2 Circuit Low  (SES, Pending, Current, Permanent, History)

0x7E8: P00F4 - Humidity Sensor Circuit Low (SES, Pending, Current, Old, Permanent, History)

0x7E8: P0102 - Mass or Volume Air Flow A Circuit Low (Pending, Current)

0x7E8: P2199 (SES, Pending, Current, Permanent, History)

0x7E8: P2229 (Pending, Current, Old)

[1SLOW1500]

OK after rewiring maf wires, and yes it looked like there could have been a short. Also cleaned out the ecm/pcm, don't think that was needed. Truck would start, run for a second and then shut down. I did the easiest thing possible. I looked at fuses. NOTHING says MAF but there is one 15amp mini blue fuse that says ENGINE. As it was blown. I replaced it and checked all connections. 

I said a quick prayer and turned the key to the ON position and looked down at the cluster to see no issues no service engine lights on.

So I turned the key and truck started right up no issues and ran fine.

 

I think the maf was always fine wiring had that one small short and and when the fuse popped that was it truck wouldn't start.

I going to buy some extra spar fuses for the truck. 

Thanks Now off to get exhaust, new smooth bumper, and more tuning. 

[Jsdirt]

SWEET! Glad you got that sorted.   

[1SLOW1500]

Yeah I metered all the wires and even rewired the harness. I know that wiring is 100%. On code is short ecm/pcm.and I took a look to find radiator coolant in the connector. I am drying it out and retry it.with electric grease on the connectors.
I have 5v and ground hard to test other wires with the digital meter in ohms when I don't know the wire pin outs. Gm tech says to short out the IAT wire to signal wire. I have 2 mafs that are good and same codes on both. I may try to get a new ecm anyways as they are cheap. But need truck running for my custom exhaust on saturday.ugh

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[Jsdirt]

Looks like you've got a wiring issue there. Circuit low suggests something is shorted - possibly the 5v reference circuit.

 

Could be a shorted sensor too - try unplugging those sensors one at a time, and see if the other codes stay cleared.

 

Also don't rule out the possibility of a bad new MAF. The saying these days is, "NEW means Never Ever Worked." Might have to try a few of them - best thing to do is borrow a known good one from a buddy or family member, or anyone willing to lend theirs, and try it out on your vehicle.