View Full Version : P0102 - 35-10 - Signal too Low - Intermittent

10-13-2018, 09:46 AM
98 1.8t

car starts idles smooth for 3 seconds and cuts off. unplugged maf and it runs smooth but not derivable

it has 12v at the red/green wire

tried a new maf, no change.

the throttle body was recently changed as the original fault code was for a throttle position sensor. Is there any common ground between these two components? Thanks

10-13-2018, 10:12 AM
also bringing up the rpm creates what seems like misfire and some smoke out the tailpipe. but it did remain idling , just no well.

10-15-2018, 12:00 AM
Throttle body adaptation?

10-15-2018, 05:26 AM
Thanks for the reply, if that's where you let it sit for a minute with the key on then I tried, and it had no change.

10-15-2018, 08:05 AM
Try unplugging the battery and let it sit for a little bit while unplugged and then plug the battery back in and run the throttle body adaptation again.

Happened to me recently where i had to do this in order for the adaptation to run correctly. Before unplugging the battery i was getting misfires after running an adaptation through VCDS.

10-15-2018, 09:29 AM
Blur2u, thanks for the reply, i'll give it a try.

10-15-2018, 01:16 PM
ok, i tried the battery off for a while, reset tb via key on for 1 minute. it starts runs rough and dies. thanks again

10-16-2018, 10:48 AM
I'm assuming you don't have vcds correct? because you can actually see the throttle position angle. In case the replacement throttle body has some issues or just issues with adapting. Try to find someone local who can scan it with VCDS.

10-16-2018, 11:15 AM
blur2u, i actually just picked up a cable to try diagnose the problem. I'll try acquire some data to see how the maf and tb are doing.

10-16-2018, 02:27 PM
VCDS is the ONLY way to do a TBA.

No other voodoo tricks will work, it's as simple as that, start there.

Unplugging the MAF and getting better results is where i'd start, MAF issue. Check ground with continuity. Is there a 5V reference on those MAFs (I honestly don't remember i'm on a v8 MAF)? Compression looks good? Plugs got good spark?

10-16-2018, 04:20 PM
Rodgman15, Thanks for the reply, unplugged Maf and the car runs smooth. I checked the 12v pin red/green wire and that was good while the key was on for a couple secs then drops to zero.
I didn't check compression but the plugs look good.

10-16-2018, 04:44 PM
I just tried the vcds throttle adapt, no change although it now has two codes, P0102, P1602

10-17-2018, 03:00 PM
so this vcds thing is pretty neat. through the advanced meas blocks i can see the maf reporting g/sec data, so it's functional. I saw a vid on group 032 about fuel trims to point toward a vacuum leak or not, however my group 032 doesn't report anything, just 0%. Am I in the wrong group for that? can anyone advise which parameter I can log to see this fuel compensation value?

10-17-2018, 10:37 PM
If you recently just unplugged the battery or cleared codes it takes a bit of driving around before you start to see values there. Should be hovering between -5% to +5%.

10-18-2018, 09:58 AM
Blur2u, thanks for the reply. The car barely driveable, I don't know if i could get enough time on it. Do you know of another approach to collect similar data? thanks again.