MAF Sensor question...

[Heartbeat Hauler]

I got a check engine light and the dealer tech said it's the MAF sensor. He also said that if it were his he would drive it until it was a real issue. So he cleared the code, then on Saturday the CEL came back. I pulled the top of the air cleaner off and looked at the sensor. The small wire did not go all the way across. It looked like a light bulb-filiment that was burnt out (filiment was attached at one end only). Anyways, I'm thinking the wire should go all the way across the sensor housing (attach at both ends). What do you all think?

Also, when pricing a new one at the dealer it was 350 bucks....:eek:

GMPARTSDIRECT.com has them for $183 (no core charge).

Autozone has them for $188 + a core charge, which means they are remanufactured. (I get $60 back when I give them the old one).

What do you all think?

JP

[AKMark]

Rockauto has them for $164 + $50 core. I've never had problems with the parts from them.

[Heartbeat Hauler]

Thanks for the heads up on Rockauto. Any idea about if the wire in the sensor is suppose to go all the way across?

JP

[AKMark]

Personally, I've never seen one that didn't go all the way across.

[DmaxMaverick]

....Any idea about if the wire in the sensor is suppose to go all the way across?

JP


Yes. Just like a filament in a light bulb. If it doesn't, it would surely explain the DTC. Check if very carefully. One of the filaments (there may be 2 or more, depending on Y/M) is flat-ish piece, welded between a post at each end, and another is kinda' rounded in the middle. If you are looking at it edge-on, you may not see it, and it may not be broken (especially with tired old eyes). You can test the continuity/resistance across the filaments through the connector (the service manual describes the desired results). Unless you are certain it is broken, I can look up the values later.

In the meanwhile, you aren't hurting anything if you drive it like this. Power may be slightly decreased, but it will be fine. Except for the SES lamp, which can be very annoying.

[Mark Rinker]

Never had an SES code set, or replaced one of these buggers. Guess I have been lucky...do they have a lifespan, or what causes them to fail?

[DmaxMaverick]

They don't fail after an "X duty cycle". They are not a "wear item", that weakens over time. They are sensitive to physical damage, vibration, overvoltage/spike, chemical contamination, and mfg defect (probably the case, most of the time). They should not be replaced as a maintenance item, as they work until they don't. Replace only when it has failed. They are considered a "no maintenance" item, but occasional cleaning (with electronics/contact cleaner) is not a bad idea. More often than not, it's the contacts in the connector that fail (corrosion, misalignment, etc.), so packing the connector with dielectric grease is also recommended.

[Heartbeat Hauler]

I looked it over again and it is definitely broken. Also the other one is kinda on the side between two posts, but I can't tell if it is connected because it is on the side view. I did use a magnifying glass...my eyes are way past tired...:D

The tech said it wouldn't hurt anything to drive the way it is, but you are right about that SES light, it sucks.

I'm waitin' on GMpartsdirect to tell me if their part is remanned or not. New ones are 352 bucks....:eek:

Thanks for the posts.
JP

[DmaxMaverick]

The $183 GMPD MAF is not a reman, but a genuine GM part. They sell GM parts, just like you'll find at your local GM parts counter. Only, at about 1/2 the price.

[ToddMeister]

If you had access to EFILive, might be able to turn off the fault code or the CEL light when that code occurs.

[Heartbeat Hauler]

The $183 GMPD MAF is not a reman, but a genuine GM part. They sell GM parts, just like you'll find at your local GM parts counter. Only, at about 1/2 the price.
I was wonderin' what the deal was here. the local autoparts stores are selling remanned MAF sensors for the same price that gmpartsdirect is selling new ones....:eek: I know there is shipping, but c'mon how can they sell new parts so cheap?




If you had access to EFILive, might be able to turn off the fault code or the CEL light when that code occurs.
I just happen to have EFI sitting next to me on the couch. I've been waiting to use this "diagnostic tool" ;) but I don't wanna have to do it every other day...:D
JP

[Heartbeat Hauler]

Well, a good buddy from the forum sent me a spare MAF sensor, I installed it and used EFI to clear the codes. It did fine for about a week and a half then the SES light comes on again....Doh!

Now when I check the codes they are:
P0106 (MAP manifold absolute pressure)
P0101 (MAF sensor performance)

Help!!!

JP

[Heartbeat Hauler]

Now, the SES light went out. I think there was a TSB about doing a reprogram on the PCM to increase the parameter range for the Baro sensor. I was told mine already had the update. Any ideas?

JP

[madmatt]

boot off????????

[Philsauto]

Now, the SES light went out. I think there was a TSB about doing a reprogram on the PCM to increase the parameter range for the Baro sensor. I was told mine already had the update. Any ideas?

JP

I am unclear as to which vehicle you are talking about, looking at your list below. Is this an LB7 motor or an LLY? There is an update for the software on the LLY, and when reflashing the PCM, you have to choose between a round air filter and a square one. The choice is critical, as the MAF reading will change drastically. I don't understand your GM dealer saying the MAF is of no consequence if you have an LLY. It has an effect on fuel delivery, and at over $4 a gallon, anything that affects fuel is of interest to me.

Anything that lights the MIL should be addressed. Once the MIL is on, your computer has lost all ability to communicate a problem to you.

You had a MAP code plus a MAF code. It may be a question of rationality; the computer does not like a comparative value and the code does not necessarily indicate the sensor that is mentioned is the problem. Your vehicle is a candidate for a skilled diagnostician, and unfortunately most diesel guys are parts-hangers. They don't know how to troubleshoot rationality codes. But if I were you, I'd look for someone to really fix it, and I don't think your GM dealer has given you good advise so far.

[madmatt]

Hey hauler,, I'm only 1 little over an hour away. If you need help, look me up here.

[Heartbeat Hauler]

I am unclear as to which vehicle you are talking about, looking at your list below. Is this an LB7 motor or an LLY? There is an update for the software on the LLY, and when reflashing the PCM, you have to choose between a round air filter and a square one. The choice is critical, as the MAF reading will change drastically. I don't understand your GM dealer saying the MAF is of no consequence if you have an LLY. It has an effect on fuel delivery, and at over $4 a gallon, anything that affects fuel is of interest to me.

Anything that lights the MIL should be addressed. Once the MIL is on, your computer has lost all ability to communicate a problem to you.

You had a MAP code plus a MAF code. It may be a question of rationality; the computer does not like a comparative value and the code does not necessarily indicate the sensor that is mentioned is the problem. Your vehicle is a candidate for a skilled diagnostician, and unfortunately most diesel guys are parts-hangers. They don't know how to troubleshoot rationality codes. But if I were you, I'd look for someone to really fix it, and I don't think your GM dealer has given you good advise so far.

Phil,
I'm talking about my 01 3500, the LLY motor didn't show up until 2004.5. My error codes are P0101 and P0106. One of them points to a MAF error and the other is MAP error. According to the Dealership it is a faulty MAF sensor, sooo I replaced it with a used MAF a friend sent me. I cleared the codes and drove it for a while and then the SES light came back on with the same codes. So then, I bought a NEW MAF sensor and cleared the codes. Drove it for a day and half and the SES light came back on. Took it to the dealer and the tech said that everything seems ok, it must be the Banks stuff I have installed. So now I have to remove the Banks harness and see it the error comes back. Personally, I don't think he knows what the hell is the problem. If I would have let them fix it they would have charged me 400 Bucks(!) for the MAF sensor and it would still be wrong.

I don't know what an MIL is and I agree with the last part of your post. Unfortunately I live in a small town and the dealership is probably the best qualified for the Duramax engine.

I am open to suggestions.

Matt,
Thanks for the offer but I would hate to drag you into something especially since I have no clue what that something is....:o
JP

[More Power]

HH,
Yes, you should remove any electronic power adder or other device that could complicate troubleshooting - before going further with a diagnosis.

Back in '04 I bought a salvage Duramax airbox for our Lil Red project. I wound up not using the box cuz it wouldn't fit into the space, but it came with a MAF sensor.... I think I paid $50 for the airbox. I did use that very same MAF sensor along with an AFE air intake system. I suspect the MAF wasn't removed from the airbox at the salvage yard because it takes a special Torx bit to remove the screws.

Jim

[madmatt]

what he's calling a MIL (malfuntion indicator lamp) and your calling an SES is the same thing. Also I believe saying most diesel guys are parts hangers is a little harsh. Some are but so are a lot of gas engine guys.

[Heartbeat Hauler]

HH,
Yes, you should remove any electronic power adder or other device that could complicate troubleshooting - before going further with a diagnosis.

Back in '04 I bought a salvage Duramax airbox for our Lil Red project. I wound up not using the box cuz it wouldn't fit into the space, but it came with a MAF sensor.... I think I paid $50 for the airbox. I did use that very same MAF sensor along with an AFE air intake system. I suspect the MAF wasn't removed from the airbox at the salvage yard because it takes a special Torx bit to remove the screws.

Jim

Yeah, I think that's what i will have to do eventually. Funny thing now is the weather has gotten really nice around here. Temps in the low 80's during the day and hi 50 lo 60's at night and humidty is low. I have not had an SES light since the weather has changed. Before the SES would illuminate after a few hours of driving. Now, I have driven over a week and no light. Coincidence? I dunno, but it sure smacks of the notorious Baro-sensor that they replaced twice already.

I also called the Banks Engineering tech line. He told me that the OttoMind does not intercept any signal except the boost signal and therefore should have nothing to do with the MAF circuit....:confused:

I guess I'll wait until I throw another SES before I disconnect everything.


what he's calling a MIL (malfuntion indicator lamp) and your calling an SES is the same thing. Also I believe saying most diesel guys are parts hangers is a little harsh. Some are but so are a lot of gas engine guys.

I have confidence in the tech guy here, but I don't think he can get past the Banks stuff. In all fairness if I were still trouble shooting computer systems I would suspect the last thing done, or something not a part of the original equipment or software.

Thanks for the education on acronyms....:D
JP