Hey all, I was driving and the yellow engine light came on. Drove home about 2 kilometers and plugged the 3100RS2 in, it came up as P0102 'mass air flow sensor' and it was listed as a stage 3 urgent code. I don't know ANYTHING about how to fix these sorts of things, I am an absolute novice, so please bear with me as I ask what might be construed as something stupid, I don't want to damage anything further. I did a little bit of research and found out that the problem could be fixed simply by spraying the MAF sensor with some chemical.

Unfortunately, it might actually be the MAF sensor that is shot. When I bought the vehicle, it was mentioned that there was a code that would pop up with something to do with the MAF. I'm willing and prepared to replace the component if necessary, I just don't want to go and spend $10 for some spray chemical if I'm going to need to fork over $100 for the part, as I'm really strapped for cash right now. I found this video and in it the guy is able to diagnose the problem by disconnecting the electrical harness from the component while the engine is running. I know nothing about cars or how to fix them, so please pardon my ignorance for asking something so seemingly stupid. Will I further damage my car if I start it and pull the harness away from the component? Thanks in advance and sorry if I seem stupid

 

That is one way to figure out if the maf sensor is bad. Having a can of MAF clean isn't a bad thing, I usually clean my maf with the stuff once or twice a year.

I'd also chase the wires from the maf sensor plug back to the ecu. It could be a wire that is damaged and shorting.

If you haven't cleared the code, I'd start there and see if it pops up again, if it doesn't pop up within a few drive cycles I wouldn't worry about it in the immediate, just keep it in mind.

 

It popped up as a stage 3 code, the most in need of immediate attention. Is it safe to drive for long? What could become damaged if it's driven and not tended to? Sorry if these questions are redundant, I'm a novice mechanic and I'm still learning lol.

I got the MAF sensor cleaner, just waiting for the wind to lessen a bit before I go spray it down. Thanks for the advice btw, I never thought of it as an investment that will eventually pay for itself via better fuel mileage

 

I'd try the reset, if it pops up right away then there is a serious issue. If it takes a bit to come back, it's probably the wiring or the maf is failing slowly.

Just make sure you reinstall the maf in the correct direction and clip the security tab back in (light grey part of the clip)

 

Hey, so I managed to disconnect the component, that MAF sensor looked BRAND. SPANKING. NEW. It looked like it was recently installed, far better than the ones I've noticed in the videos where they clean the part with SensorKleen. I still sprayed it down, but then I logged into my RepairSolutions account and noticed a list of predicted repairs and the very first item among seven was to 'Replace Mass Air Flow (MAF) Sensor' I mean, the thing literally looked brand new, I'm wondering if the kid I bought the car from had it installed wrong. I'm going to upload a photo for you to see for yourself

 

Hey so a quick update, I went out with the code reader and did NOT start the car, I turned the ignition to 'on' and connected the device. No codes popped up. The yellow check engine light, however, was still on. Because I saw no codes on the code reader I decided to start it up and voila! Yellow check engine light was gone. Decided to take it for a spin for about a mile and there still wasn't any codes. Came home, turned the car off, took the code reader inside and decided to go for another spin. Unfortunately, the check engine light came on again after about maybe a mile or two of driving. This time, I managed to snag a picture of exactly what the code reader said, I'm going to upload a photo. I'm going to presume it has something to do with the wiring, I'll going to upload a few photos of what the wiring looks like underneath the hood (it looks pretty nasty) If it is the wiring that is faulty, how much does it cost for the repair usually? And can it be done by an amateur such as myself?

 

If your scan tool can monitor the output frequency of the MAF sensor, you could watch the signal and see if it randomly drops (I think below 300Hz or so) or isn't reading proportional to airflow, clear the code before doing this test as it will have to fail twice to set the DTC code. Easiest thing to do is to inspect the wiring by looking for any signs of abrasion on the wire loom tubing or the wires themselves. I see electrical tape on some of the wires which could be masking a problem if it wasn't put there from the factory. You could also look for cracks/damage in the wire insulation, you would probably see corrosion or bare wire exposed. Water will draw into the wire and over time cause corrosion further away from where it gets in. Also check the MAF sensor connector for corrosion or bent pins. Good Luck!

 

I second checking the female connector for corrosion.

I notice the grey retention clip is missing from the female connector, how tight of a fit is the connector to the maf sensor? The airbox/intake tunes can move around more than you think and it might be wiggling the connection causing interrupted signal, not a for sure thing just something simple and cheap to check.

 

Hey, sorry for the late reply, I've been busy and my car has been parked this whole time.

I checked the connector for corrosion or pins that might have been pushed out of place, everything seems fine, there's definitely no corrosion. And the female connector seems fine, I mean I'm a novice, my judgement might not be the best but I do need to put pressure on the top of it to remove it. It's definitely not something that just slides off.

Someone sent me this on Reddit https://ricksfreeautorepairadvice.com/cobalt-p0102/

I pulled the EXH 10A fuse out of the fuse box and tested it using my multimeter using the ohms test and it beeped and seemed fine. I haven't yet checked near the clutch pedal position switch or the oil filter adapter housing, would I need to check these two additional components if I didn't find a blown EXH fuse?

The only thing I didn't yet check for is a chaffed oxygen sensor wiring component, where do I find that? And if it's not anything on this list I've compiled, what would my next step be? I'm starting to get worried that this is something really complicated