NewBeetle.org Forums banner

1 - 9 of 9 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
Purchased a 2005 VW Beetle 2.0 / Convertible on Tuesday. Took it to the our mechanic on Wednesday to schedule to have routine timing belt replaced and other maintenance done to it. We also had him look to see what the small rattle was we were hearing from the drivers side thinking a bracket or something might be loose. We discovered the Catalytic Converter was needing to be replaced after an 02 sensor code and another code about the catalytic converter showed. We left his shop and went straight to the muffler shop to have the catalytic converter replaced. After a couple of hours went by they came and asked us if we had ever had problems with the car not starting because they could not get it to start. The first thing my husband asked them was if it was grounded when they welded the new one in place. Here is what we discovered. The key was left in the ignition, they use some type of surge protector on the battery but actually never unhooked the battery. After realizing the car wouldnt start we noticed fuse #43 the engine control element fuse was blown (never having blown fuses before). Just really needing some suggestions we are very fearful that the ECU could have possibly been fried. The car was towed back to the mechanic and he has replaced every sensor that the scan tool is showing bad. Once clearing the codes we are getting all kinds of crazy codes on even new sensors. ........very frustrated
 

·
Registered
Joined
·
3,690 Posts
Need to slow down a bit here.

Your mechanic needs to quit replacing parts and sensors. Many times the sensors are not the problem

I would never had any exhaust welded as you can get a good aftermarket Catalytic Converter with flex joint for around $250. But this is a bit late now.

So was welding performed on the car?

Likely the car was jumped backwards? This could had caused the fuse to blow.

I would have your current mechanic disconnect the battery and touch the battery terminals together for at least 30 seconds, this will drain all the capacitors in the modules and put them back in default mode.

What sensors have been replaced at this point?
What DTC codes are present at this point?
Does the car just crank, but not start?
Has the current shop tried to keep the throttle floor while cranking the engine to put the engine in "Clear Flood Mode"?
Has the current shop tired starting fluid to see if there is any response when trying to start the engine?
Has the crank sensor been replaced since the car will not start?
Has the current shop checked for spark and/or replaced the ignition coil?
Has the current shop checked the fuses on top of the battery?

There are an awful lot of questions that need to be answered and additional info that is needed in order to be able to offer more assistance.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #3
ok the maf sensor and crank position sensors were replaced. that did not fix the problem leading our mechanic to believe the ecu was damaged.

our mechanic specializes in european and german automobiles and is very knowledgeable and has never seen this. today it was still showing a maf sensor code even though a new one has been installed as well as the crank position sensor. there are like 4 other codes showing now.

the car turns over but wont fire.

all fuses are good ...the only one we found blown was fuse #43 and it was replaced after the welding and hasnt blown since.

welding was performed on the car with the key in the ignition and battery cables not unhooked they used the surge protector?

do not know the answers to the other questions.
 

·
Registered
Joined
·
3,690 Posts
Problematic MAF sensor will not likely cause a no start condition. You can unplug the MAF sensor and the car will start without problems it will be driveable, but on some cars if the MAF is disconnected it may go into limp mode at a certain speed or engine RPM. No need to replace the MAF for a no start, just disconnect it.

What I would need to know is the exact codes AND for the sensors, the current shop needs to see if the Ground and 5 Volt or 12 Volt reference is available at each sensor. Most active sensors like crank, cam, MAF, MAP sensors typically all have a Ground and either a 5 Volt or 12 Volt reference, then there is usually an output single from the sensor. So many of the active sensors have 3 or more terminals. Most of the temperature sensors do not have 3 or more terminals and most of the time they do not have a ground and reference Voltage.

It is possible that something was zapped when welding. Shop should have disconnected the negative cable from the battery and connected it to the positive terminal with a jumper. The problem is with putting some form of surge suppressor on the battery, you are relying on all the ground connections in the car to be in good shape. The problem is most cars and trucks have ground problems and if there are problem grounds on the car, then the welder can induce Voltage into the wiring and modules likely causing problems.

Pretty clear that you DROVE the car into the exhaust shop and had to have it TOWED out, so I would be having a discussion with the exhaust shop about how they or their insurance company is planning on paying for the repairs.

Again, I would tell your current shop to slow down on sensor replacements, they obviously do not understand that a MAF error does not require an immediate replacement, just unplugging the MAF and moving on to the next issue would be advisable.

If you can get your shop to provide exact OBDII DTC/trouble does in the Pxxxx format, we can comment and give some guidance.

Likely the upper portion of the dash will need to be removed to access the ECU. Likely grounds will need to be checked. While the dash is apart, have the cabin air filter replaced as it likely will be the original.

Also have the shop check for Airbag, ABS and Transmission errors at this point assuming they even have a tool capable of checking for these codes. Many shops are under equipped to check to this level. Not sure what tool(s) they have available, but I even personally have tools cable of this.

Good luck and keep us up to date as to what is going on.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #6
our saga continues. After trying everything possible our Mechanic decided it would be in the best interest for all involved for the car to go to the VW dealership. After speaking with the dealership directly they have told us that there is a great possiblitly that if the muffler shop did not disconnect the o2 sensor that is located close to the catalytic converter that it is wired in directly to the ECU and it could have possibly shorted out and for better choice of words "fried" the ECU. We are waiting to hear :confused:
 

·
Registered
Joined
·
3,690 Posts
Man, sorry to hear things are not progressing. You do now know if the shop connected the ground to the body or the exhaust system. If they made a body connection, this would have been BAD, event an exhaust connection is questionable if the exhaust is not a 1 piece welded system.

O2 sensors would be one path for a surge or stray Voltage, but there could also be other paths!!

I would like get the exhaust shop to get their insurance company on this because it might be best at some point for the insurance company to buy the car from you???

The problem here is where do the problems stops, fried ECU, fried dash cluster/immobilizer??? How many months before this gets solved???

Assume the worst, expect the best. But watch out for your wallet, the exhaust shop screwed up!
 

·
Registered
Joined
·
5 Posts
Discussion Starter #8
Update:

VW Dealership technician says he can not prove that the welding is what caused this issue...

I call crap on that.

Dealership is saying that we have fried o2 sensor and fried ECU. Its just very ironic that the car ran FINE the day we took it to the exhaust shop. We had just left the mechanic and the code reader showed a bad o2 sensor and catalytic converter.....again the car ran fine.

It wasnt until they replaced the catalytic converter, that the fuse #43 (engine control)blew and now the ecu and o2 sensor are fried. Coincidence???

The exhaust shop owner is wanting to see the broken parts before he will pay for it?????

I know nothing about cars but it doesnt seem to hard to figure this all out.....blown fuses...fried sensor...fried ECU all after having the catalytic converter welded.....


do you agree?:rant2:
 

·
Registered
Joined
·
3,690 Posts
Here is the deal, you drove your car to the exhaust shop for a specific service of replacing the catalytic converter. I assume due to a P0420 code????

You should have put the brakes on with the P0420 code as this is an Auto Industry problem with "false" or overly sensitive catalytic converter efficiency codes. Many times the best solution is an ECU update, likely VW has a technical bulletin on this issue.

Anyway if the O2 sensors would not have been working, likely they would not have been able to easily trigger a P0420 code.

Now the other problem here is you have 3 shops involved in the mess.

Shop #1 your Indy, can likely document what they original found and what they found when the came back and would not run.

Shop #2 the exhaust shop, well they do not see that they did anything wrong, they just think you have a problem car.

Shop #3 the dealer, they have no vested interest in doing anything but repairing your car and cleaning out your wallet. They do not want to get into a finger pointing exercise as they will have been paid in order for them to release your car. The also cannot "prove" without a doubt as to how everything got damaged.

Shop #2 the Indy in somewhat in the middle as they did not create the problem, they did not fix the problem, so their comments are likely 2nd hand speculation.

You should make sure you have documented repair orders from the Indy and the Dealer. The exhaust shop does not need any failed parts, likely the ECU needs to be sent back as a core for repair via VW.

I would demand that the exhaust shop give you their insurance company info so you can bypass the exhaust shop and let the insurance company sort it out. Also contact your insurance company and see if they have any soft of damage coverage or can help out, I doubt it, but you took your car to the exhaust shop and they damaged your car.

I am sure the exhaust shop will claim they did everything the same way they work on all cars they perform welding on, but something went wrong. Either there was human error, a connection slipped off or something was wrong with the electrical path on the exhaust and something got cooked.

Common sense would likely dictate that you should unplug O2 sensors and likely disconnect the battery before welding any exhaust parts with an electric weld while parts are on the car.

Not sure why they attempted to weld anything on the car anyway??

Not sure how your exhaust is configured, but my car had 3 nuts on the turbo flange and 1 slip coupler, disconnect 2 O2 sensors and the the downpipe/flex coupler and catalytic converter all comes out. With a torch to heat up the 3 nuts on the turbo flange, less than 10 minutes and I had the entire front exhaust on the ground.

My guess is the exhaust shop attempted to shortcut something to save time and make more money???

I would call around and ask other exhaust shops how they would perform a similiar repair and document what process they use?

Good luck, I realize this is not fun, you are out a bunch of money, but it is pretty clear based upon the events the the exhaust shop needs to step up and either pay the bill or turn it over to their insurance company.

If not contact the local TV and newspapers to have their Consumer Reporters have fun with this!
 
1 - 9 of 9 Posts
Top