MAF p0102 code

[specelec]

I have had a p0102 code for a while now, and have checked for leaks around air box / throttle body, removed K&N filter and replaced with paper one, replaced MAF sensor with refurb unit from Murrays, replaced hose from side of throttle body to crankcase, replaced PCV valve with new, and I am still getting this code.

I checked the ground and voltage at the MAF and had ~12volts, and ground was about 30 ohms above battery ground.

Any ideas on what to try next???

I am at 178K if that helps.

[mikedamech]

30 Ohms? To check a mass sensor you need a Lab Scope. I hope your not checking voltage and resistance readings with an Analog meter, you need a digital so you dont let the magic smoke out the mystery box..

[specelec]

I was just checking to see what was supplying the MAF sensor, and was using a digital voltmeter.

I do have access to a scope, and could check the signal wire.

Any ideas what signal I should see?

Also received a suggestion that the ground wire being 30 ohms above grond is bad.

Anyone know where the MAF ground point is?

Thanks.

[sfeaver]

The MAF just grounds to chassis ground (Black/White wire at the connector). You shold see 12v from Pink to black white at the connector. And from the Yellow wire to ground you should see 5v with the MAF disconnected.

The code sets when the engine run time is more than 0.4 seconds, RPM higher than 300, and system voltage more than 8 volts, and the MAF frequency is 10 Hz or less for more than 1 second.

The Higher the flow, the higher the freqency.

Do you have access to a scanner? That would make this repair a bit easier, as it will show you what the MAF sensor is outputting, or at least what the computer sees.

See if that wire shows 5volts.

Also, after you switched the sensor did you clear the codes? It wont clear the light on its own until you've had three consecutive drive trips with the test being run and passed.

I've also seen wires break at the crimp, or being held on by one strand which will cause stuff like this too. Give them a tug.

Hope that helps a bit,

Scott

[specelec]

Thanks for the info, I checked the signal wire.....and no voltage. I found the wire was broken where it comes out of the loom just before the sensor.

Repaired wire and MIL is gone.

Not sure that all problems are gone, but I am keeping an eye on it.

Could driving it with that problem for a couple of months have caused any other issues (too rich, too lean, etc)


Thanks again.

[sfeaver]

Glad to hear you found the problem. The PCM defaults to a certain value when it doesnt get a signal from the MAF sensor, so you should be fine. I wouldnt worry until you get a code from a fault it something is not quite right. But without that sensor working, things shouldnt have been too far off. Broken wires are hard to diagnose so that is a good find!

Scott