asr helps rough running, what's up with this

[donell666]

My 2000 1.8 beetle, runs rough when the rpms get up but I can press the asr button and helps the running to smooth out. does anyone know what's going on? thanks

[thexnightmarexstops]

are your front tires properly/equally inflated? or the same tire size?

if not i could see how maybe the difference in circumference of the tires could play tricks on the traction control system, making it believe it is losing traction because of the different spin rates of the tires.

thats all can think of???

[zeusenergy]

Originally Posted by donell666

My 2000 1.8 beetle, runs rough when the rpms get up but I can press the asr button and helps the running to smooth out. does anyone know what's going on? thanks

Is the light ON when it runs correctly? If so, you are just disabling traction control as the previous poster said. It's tied into the drive-by-wire (DBW/FBW) throttle, the ABS system, cruise, engine management, etc. My guess is there may be something interfering with one of the wheel sensors that may be causing it. Take your wheels off and pull the sensors out, blow out the toothed gears and sensor. Get a scan for codes and make sure all is well. Try unplugging the MAF sensor cable near your air filter box and take a ride to see if that helps. Beyond that, you've got me!

[donell666]

Thanks guys for all of the tips, I will try them and then get back to you guys. I really appreciate the help

[zeusenergy]

Originally Posted by donell666

Thanks guys for all of the tips, I will try them and then get back to you guys. I really appreciate the help

Don't mention it. Right now I got ABS, BRAKE, CEL lights lit up like an XMas tree on my dash... right after changing a battery in 6 deg. F temps...

[thexnightmarexstops]

Originally Posted by zeusenergy

Don't mention it. Right now I got ABS, BRAKE, CEL lights lit up like an XMas tree on my dash... right after changing a battery in 6 deg. F temps...

your sure your MAF isnt unpluged?

[Too Cold NB1.8T]

Understand that unplugging sensors/parts such as the MAF sensor for diagnostic purposes on this car will not give any clues or tell you what the source of the problem is, these cars have redundant backup's.

When you unplug something like the MAF sensor, the ECU will simply throw a code and redirect how/where it gets the needed information, the car will usually still run but differently and through other means, this is why the old school "disconnect" method of diagnostics normally does not work on OBDII cars like this one.

Working on these cars and running diagnostics here requires a vagcom or scan tool, there is no getting around it.

[zeusenergy]

Originally Posted by thexnightmarexstops

your sure your MAF isnt unpluged?

I found my problem, but it's not gonna help the OP.
Battery change-out forced me to take the cover off the battery, and one of the connections inside came loose without my noticing. I think the connector (2" wide, three wires?, right side) may be a dedicated connection for ABS. Either way, the wires for it got wrapped around the rear upright bracket and when I shut the lid, it pulled off the connector. I have no "idiot" lights any longer

[zeusenergy]

Originally Posted by Too Cold NB1.8T

Understand that unplugging sensors/parts such as the MAF sensor for diagnostic purposes on this car will not give any clues or tell you what the source of the problem is, these cars have redundant backup's.

When you unplug something like the MAF sensor, the ECU will simply throw a code and redirect how/where it gets the needed information, the car will usually still run but differently and through other means, this is why the old school "disconnect" method of diagnostics normally does not work on OBDII cars like this one.

Working on these cars and running diagnostics here requires a vagcom or scan tool, there is no getting around it.

So, what you are saying is that disconnecting the MAF will just force the ECU into a "MAF" less mode, and you won't be able to find the culprit because other systems are ALSO bypassed when you unplug it? I'd love to know how this works and what systems are disabled during a MAF disconnect! Give us more info!! Please?

[turbos03]

Originally Posted by Too Cold NB1.8T

Understand that unplugging sensors/parts such as the MAF sensor for diagnostic purposes on this car will not give any clues or tell you what the source of the problem is, these cars have redundant backup's.

When you unplug something like the MAF sensor, the ECU will simply throw a code and redirect how/where it gets the needed information, the car will usually still run but differently and through other means, this is why the old school "disconnect" method of diagnostics normally does not work on OBDII cars like this one.

Working on these cars and running diagnostics here requires a vagcom or scan tool, there is no getting around it.

and the award for best advice on how to diagnose a VW (or any OBDII CAR) goes to Too Cold NB1.8T....

folks get a Vag-Com, or a simple scan tool... it really is your friend...

[Too Cold NB1.8T]

Originally Posted by zeusenergy

So, what you are saying is that disconnecting the MAF will just force the ECU into a "MAF" less mode, and you won't be able to find the culprit because other systems are ALSO bypassed when you unplug it? I'd love to know how this works and what systems are disabled during a MAF disconnect! Give us more info!! Please?

No, that is not what I said, by unplugging say the MAF sensor you are eliminating it's contribution from the information pool, this excites the ECU into storing one or more DTC's and then it illuminates one or more dash warning lights (EPC and maybe a CEL), the ECU doesn't bypass other functions per-say, it draws from other sources/systems in an attempt to gather enough information to continue operations on a sub-level, this allows the vehicle to be driven so that one is not stranded and so the vehicle can be driven to a repair facility.

This situation should be treated somewhat like one of those miniature spare tires, temporary, the car should not be driven in this condition for an extended period of time or further damage/problems could result.

On a 70 Plymouth Road Runner with a big block V8, you can unplug various components as a method of diagnostics, often you will be able to determine what has failed or in not functioning up to par by following this procedure, this rarely works on newer vehicles for the reasons I have mentioned.

In the case of a MAF sensor, a dealer technician might do one or both of the following to determine whether or not an MAF sensor is bad:

1. Connect the vehicle to a vagcom and analyze the readings.

2. Temporarily install another MAF sensor that is known to be good, then proceed from there with his/her diagnostic.

[zeusenergy]

Originally Posted by Too Cold NB1.8T

No, that is not what I said, by unplugging say the MAF sensor you are eliminating it's contribution from the information pool, this excites the ECU into storing one or more DTC's and then it illuminates one or more dash warning lights (EPC and maybe a CEL), the ECU doesn't bypass other functions per-say, it draws from other sources/systems in an attempt to gather enough information to continue operations on a sub-level, this allows the vehicle to be driven so that one is not stranded and so the vehicle can be driven to a repair facility.

This situation should be treated somewhat like one of those miniature spare tires, temporary, the car should not be driven in this condition for an extended period of time or further damage/problems could result.

On a 70 Plymouth Road Runner with a big block V8, you can unplug various components as a method of diagnostics, often you will be able to determine what has failed or in not functioning up to par by following this procedure, this rarely works on newer vehicles for the reasons I have mentioned.

In the case of a MAF sensor, a dealer technician might do one or both of the following to determine whether or not an MAF sensor is bad:

1. Connect the vehicle to a vagcom and analyze the readings.

2. Temporarily install another MAF sensor that is known to be good, then proceed from there with his/her diagnostic.

Thanks for the extended explanation. What I was getting at is that if you unplug and it runs right, you could narrow it down to a bad MAF, but apparetly that's not so. Learn something new every day