P0102 Code - Getting frustrated

[Heyobie]

I need direction. Been chasing a MAF problem and can't get rid of the Check engine light.

I am getting a P0102 which is a MAF low voltage input. I have replaced the MAF twice and I still get the code at about 40 miles after reset. I replaced the connector that goes to the MAF (it was slightly damaged). It was a little tricky but I was able to make it look beautiful.


There is definitely something else wrong. Intermittently, the car will shutdown when at idle. Then I can restart.

Any thoughts appreciated. Not sure where to go from here.

[geniushanbiao]

I think most of the time P0102 is a connection problem. The connector on the MAF sensor is probably loose or rusted. Check it carefully and also check the wires that go into the connector.

[Heyobie]

I had the connector completely apart. And I mean completely. I bought a new housing from VW for about $8. To remove each wire from the old connector took a bit delicate surgery. Not having the super duper secret tool from VW used to remove each pin, I basically destroyed the plastic one pin at a time. I examined each connection. There was no rust, each connector was clean and the wires appeared to be OK. They went into the new connector beautifully.

I can't rule out that a wire could be broke inside, but everything looked good to me.

[Blugg]

I'd put money on it being the air intake valve

Needs cleaning or replacing.

What year

[geniushanbiao]

Although it doesn't happen frequently, you can check the connectors to the ECU to see if they are loose or so. The ECU's holders are plastic and will fall apart after long time shake which will make the ECU hitting everywhere when you drive.

Also the MAF still can be bad even you buy it new. I had this experience with advanceautoparts too and finally I asked them to replace it for me. It varies a lot where you buy this crappy.

Originally Posted by Heyobie

I had the connector completely apart. And I mean completely. I bought a new housing from VW for about $8. To remove each wire from the old connector took a bit delicate surgery. Not having the super duper secret tool from VW used to remove each pin, I basically destroyed the plastic one pin at a time. I examined each connection. There was no rust, each connector was clean and the wires appeared to be OK. They went into the new connector beautifully.

I can't rule out that a wire could be broke inside, but everything looked good to me.

[Blugg]

Originally Posted by geniushanbiao

Although it doesn't happen frequently, you can check the connectors to the ECU to see if they are loose or so. The ECU's holders are plastic and will fall apart after long time shake which will make the ECU hitting everywhere when you drive.

Also the MAF still can be bad even you buy it new. I had this experience with advanceautoparts too and finally I asked them to replace it for me. It varies a lot where you buy this crappy.

Agreed that aftermarket parts in some cases are crap. Especially sensors, but i'll stick with my guess below

Originally Posted by Blugg

I'd put money on it being the air intake valve

Needs cleaning or replacing.

What year

[Heyobie]

Where is the air intake valve. Don't know that one. It is a 2001 Beetle

[Blugg]

Originally Posted by Heyobie

Where is the air intake valve. Don't know that one. It is a 2001 Beetle

I'd definately go with the air intake valve. I had this problem on my 1.6 SR Bug.

Had 2 mechanics, one VW dealership and it was the engine tuner who told me to clean the valve out. It fixed it

I don't know where it is either But what happens is it get's clogged with crap over time. I had mine cleaned out. Cheaper than a new one. Worked perfectly for 2 years after until i sold it. It throws out that MAF code you quoted. I'll never forget that code

[cjohnsontech]

Are you talking about the Butterfly in the Throttle Body? I've never heard of it as an Air Intake Valve, though

[Blugg]

Originally Posted by cjohnsontech

Are you talking about the Butterfly in the Throttle Body? I've never heard of it as an Air Intake Valve, though

The site i usually use for the pictures and item numbers http://www.wagenstad.com/ is down, been a few weeks now So can't get a picture of what i mean. Over this side of the pond it's the air intake valve.

Will also kill the revs shutting off the Bug. But can be restart after.

[Heyobie]

Can someone tell me where the air intake valve is? Or describe what it is?

Thanks

[IndyTom]

Originally Posted by Blugg

The site i usually use for the pictures and item numbers http://www.wagenstad.com/ is down, been a few weeks now So can't get a picture of what i mean. Over this side of the pond it's the air intake valve.

Will also kill the revs shutting off the Bug. But can be restart after.

I think what he means is the Diverter Valve? If it is bad it could throw a code. Also the P0102 is an OBDII code and not a VAG code. It basically means "Mass or Volume Air Control Circuit-Low Input". It could be a vacuum leak. Did you check all the hoses underneath the engine cover? They do get brittle from the heat and crack or fail. I replaced all of my hoses with Silicone hoses to avoid any vacuum leaks.

[IndyTom]

Originally Posted by Heyobie

Where is the air intake valve. Don't know that one. It is a 2001 Beetle

I also never heard of an air intake valve. I heard of an Idle Air Control Valve but I believe after 1996 they switched to a different system that controls the Throttlebody directly.
Cleaning your throttlebody wouldn't hurt and perhaps checking the O2 Sensors.

I would also check your Secondary air pump and the hoses going to it. That pump is known to fail.
Do you have a Vag com in order to get a more detailed readout?
A basic OBDII scanner is pretty vague in diagnosing these problems.

[geniushanbiao]

I suggest you do this: First use a voltmeter, backprobe the PIN5 of the MAF sensor and see what the signal is(Don't disconnect the MAF sensor when you do this). Most of the time when idle the voltage should be like 1V or 1.5V something and if you rev the engine up it should be rising. If you can't see sufficient signal when idling then test PIN2 and PIN4 for 12V and 5V supply, then use Ohm meter test PIN3 for continuity with GROUND. If power supply and GND are all good then the sensor is still bad and try get a good one. If you can see signal and doesn't rise with engine rev up accordingly then there should be vacuum leak. If everything seems to be fine and you still get the code, check for electrical connection loose.

[geniushanbiao]

I never heard of this either. I know that on new beetles the throttle is the ONLY thing that controls air entering the engine.

Originally Posted by IndyTom

I also never heard of an air intake valve. I heard of an Idle Air Control Valve but I believe after 1996 they switched to a different system that controls the Throttlebody directly.
Cleaning your throttlebody wouldn't hurt and perhaps checking the O2 Sensors.

I would also check your Secondary air pump and the hoses going to it. That pump is known to fail.
Do you have a Vag com in order to get a more detailed readout?
A basic OBDII scanner is pretty vague in diagnosing these problems.