P1508 + P0492 codes...symptoms...opinions..any guess?
#1
11-24-2007, 03:29 PM
Join Date: May 2004
Location: Lo Barnechea & Viņa del Mar
Age: 52
Posts: 1,036
Rep Power: 64 
P1508 + P0492 codes...symptoms...opinions..any guess?
Yesterday in traffic I got a PSM and ABS lights come on but went off after restart the car.
Today driving in canyons with a group of friends I loose all throttle and the dash beeps + displays Check Engine + Shutdown Consult Dealer immediately (or similar words). At this point I did pull over as there is no throttle, stop and the engine was running rough and full throttle gives you a 200 rpm increase and that's it. Ok then; turn it off, restart the car and all is well again with the CEL on and runs great. Then returning home the Check Engine light disappear and the car still running great but I did run durametric:
Motronic 7.8
Current Fault Codes
P0492 (yesterday on traffic)
Porsche fault code 208 - Secondary-air system bank 2
P1508 (today driving in canyons)
Porsche fault code 408 - Function monitoring
Torque comparison
For what I found:
P1508 Torque Comparison Function Monitor - Signal Implausible
Possible cause of fault
- MAF sensor faulty or at fault detection threshold
- DME control module faulty
I have OEM filter and AirBox, 30k milles, and I have never clean or touch the MAF.
Do these symptoms are a clear MAF failure or polluted?
Thanks!
Today driving in canyons with a group of friends I loose all throttle and the dash beeps + displays Check Engine + Shutdown Consult Dealer immediately (or similar words). At this point I did pull over as there is no throttle, stop and the engine was running rough and full throttle gives you a 200 rpm increase and that's it. Ok then; turn it off, restart the car and all is well again with the CEL on and runs great. Then returning home the Check Engine light disappear and the car still running great but I did run durametric:
Motronic 7.8
Current Fault Codes
P0492 (yesterday on traffic)
Porsche fault code 208 - Secondary-air system bank 2
P1508 (today driving in canyons)
Porsche fault code 408 - Function monitoring
Torque comparison
For what I found:
P1508 Torque Comparison Function Monitor - Signal Implausible
Possible cause of fault
- MAF sensor faulty or at fault detection threshold
- DME control module faulty
I have OEM filter and AirBox, 30k milles, and I have never clean or touch the MAF.
Do these symptoms are a clear MAF failure or polluted?
Thanks!
#3
11-24-2007, 04:29 PM
Looks bad, without knowing what the voltage is at just "on" and at "idle" I would tell you to clean it, reset then see if it comes back. if it does then it is due for a MAF.
#6
11-25-2007, 07:57 PM
Join Date: May 2004
Location: Lo Barnechea & Viņa del Mar
Age: 52
Posts: 1,036
Rep Power: 64 
I did use Durametric after driving this afternoon, resetting up and I follow your instructions getting this actual values:
it seem OK because the actual values has to be 1.2 to 1.5 V at idle speed.
Then I did with the car stop but at different speeds:
Thus, with this values and the car running fine for now, should just clean it? or the MAF will die very soon?
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#9
04-09-2009, 01:28 AM
can someone point me to where the MAF sensor is, and what i should use to clean it, and finally a price for the part if i need to replace it...not dealer price, aftermarket if avaliable.
thanks.
thanks.
