Check Engine Light Code P0102 Mass Air Flow Sensor

[mmoore]

The car runs fine but the check engine is on. I had Autozone read the code and it was P0102. I subscribe to DIY Alldata and it indicates that the signal from the MAF(Mass Air Flow sensor is below the lower limit. It indicates that the signal wire from the MAF is broken or is shorted to ground. I disconnected the MAF and put an ohm meter on pin 5 of the connector.

It read 10,000 ohms. That says to me that the wire is not open or shorted to ground so something else is wrong. According to Alldata pin 4 of the MAF is the 5 volt supply line and pin 5 is the signal line. The ohm meter shows a resistance of 45,000 ohms from pin 4 to pin 5 of the MAF. Can anyone tell me if this is a good value. My theory is that 45,000 ohms is way to high and the MAF is bad. Just for reference the ohm reading on the connector are pin 1 - 1,000 ohms , 2 - 100 ohms, 3 - 0 ohms, 4 - 1,500 ohms, 5 - 10,000 ohms. The ohms reading on the MAF are pin 5 to 1 - 19,000, 5 to 2 - 60,000, 5 to 3 - 15,000, 5 to 4 - 45,000. Before I replace the MAF I would like to get your suggestions.

[joee]

If this is a Boxster I hope you have not installed a K&N air filter. They really mess up MAFs on Boxsters.

Joe

[mrmickeymouse]

PM me with an E Mail. I will send you something to help.

BTW - the K&N filters are good except when over oiled [seems many people get happy with the oil]. I have run one for over six months without a problem.

Scott

Edited October 28, 2004 by mrmickeymouse

[mmoore]

It a 99 Boxster with the stock air filter.

Mitch

[mmoore]

PM me with an E Mail. I will send you something to help.

Scott

<{POST_SNAPBACK}>

I sent you a PM but never got an email. Let me know if I need to send you another PM.

Mitch

[folthoff]

If this is a Boxster I hope you have not installed a K&N air filter. They really mess up MAFs on Boxsters.

Joe

Just wanted to set something straight.. The K&N filter will not mess up your Boxster or any other car they make filters for. K&N would not manufacture a filter unless it meets certain criteria. I have spoken to K&N engineering about this and this is what they told me. >> The air flow from the K&N is much greater than conventional paper filters. It is recommended that the battery be disconnected for one hour before driving the car allowing it to reset all the previous adaptive memory settings. If this is not done the ecu will not understand why it has a greater air flow and trigger the cel. K&N has done extensive testing on this and could not confirm any complications to the maf. I have the K&N in my 2000 Boxter S and the first time I drove it, it triggered the P0102 code. So I called K&N. No trouble since then. If you do not agree then call K&N engineering yourself at 1800-858-3333.

Frankie Olthoff

[mikefocke]

You tried cleaning it?

http://mike.focke.googlepages.com/checkeng...ssairflowsensor

[MelissaInNJ]

You tried cleaning it?

http://mike.focke.googlepages.com/checkeng...ssairflowsensor

Thank you for posting that link. I need to do this this holiday vacation. Seeing as I typically add fluids and change wipers and pay someone for everything else...I needed CLEAR instructions on how to do this. THANKS!!!

Melissa in NJ

[jmatta]

As folthoff said, a K&N will not harm the car if installed and oiled properly (I've been using them for years on my 911s). I didn't know about re-setting the ECU, but had an interesting experience after installing my EVO High Flow with K&N filter. The car ran perfectly until I pulled up to a stop light after a fairly lengthy highway drive. The car idled miserably for about 15 seconds, the CEL came on; then the car corrected the idle and the light went off. Never have had a problem since (in more than 8 months). I can only assume the ECU "figured it out" and made adjustments. I check for fault codes, but there were none stored. BTW, the car is an'02 S.

[986Jim]

The K&N will screw up your MAF! It's true. Also, remember don't get too close to the edge of the world as you may fall off...

[Stefan]

K&N is pretty vigorous about dispelling this rumor. And they put their money where their mouth is. I'm guessing that they are correct and that the rumor is incorrect.

Ref:

http://www.knfilters.com/MAF/MAFTestresults.htm

http://www.knfilters.com/MAF/massair.htm

http://www.knfilters.com/MAF/massairpledge.htm

[jmatta]

As is the usual case, it's the nut behind the wheel that causes most the problems. Learn to follow directions.

[vfxbox]

The car runs fine but the check engine is on. I had Autozone read the code and it was P0102. I subscribe to DIY Alldata and it indicates that the signal from the MAF(Mass Air Flow sensor is below the lower limit. It indicates that the signal wire from the MAF is broken or is shorted to ground. I disconnected the MAF and put an ohm meter on pin 5 of the connector.

It read 10,000 ohms. That says to me that the wire is not open or shorted to ground so something else is wrong. According to Alldata pin 4 of the MAF is the 5 volt supply line and pin 5 is the signal line. The ohm meter shows a resistance of 45,000 ohms from pin 4 to pin 5 of the MAF. Can anyone tell me if this is a good value. My theory is that 45,000 ohms is way to high and the MAF is bad. Just for reference the ohm reading on the connector are pin 1 - 1,000 ohms , 2 - 100 ohms, 3 - 0 ohms, 4 - 1,500 ohms, 5 - 10,000 ohms. The ohms reading on the MAF are pin 5 to 1 - 19,000, 5 to 2 - 60,000, 5 to 3 - 15,000, 5 to 4 - 45,000. Before I replace the MAF I would like to get your suggestions.

I wouldn't check with Autozone to read your CODE. Take it to the porsche dealer and have them read proper reading.

Personally I love my K&N filter, and over 60k miles on my new engine and still running fine without any engine warning lights.

[dphil66]

As said before, disconnect the battery and try it again.

Leave it disconnected for at least 50 seconds to reset the ECU.

[leonard summerhill]

how to test MAF with voltmeter