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Discussion Starter · #1 ·
I have a 2001 Beetle I bought my wife 4 month ago, I have had it at 3 different shops all of which were NO help...

First thing first, the most recent items replaced after reading this forum ( Brake Switch, Fuel Relay, Plugs )

Now on to what the car is doing, Start it in the morning and it shakes like a Vibrating Massage Chair and dies. Restart but this time giving the car gas on and off and it will do the same shake but it will clear up after a few seconds. Then off we drive 8 out of 10 times I give it gas and the car doesn't accelerate then all of a sudden the car jumps forward and accelerates. Driving down the highway the car does this same thing it will be driving " OK " I go to pass a car and in the middle of the pass the car stops accelerating ( NOT FUN, TELL ME ABOUT IT )

On to the codes, I pulled these codes with Genisys EVO scanner

Cylinder 1 Fuel Injector short circuit to ground
Cylinder 2 Fuel Injector short circuit to ground
Cylinder 3 Fuel Injector short circuit to ground
Cylinder 4 Fuel Injector short circuit to ground
Random Misfire Detected
Cylinder 1 Misfire Detected
Cylinder 4 Misfire Detected
Bank 1 Sensor 2 Heating Circuit Short to ground
Load detection implausible value
Bank 2 mixture adaptation area 1 lower lean limit not reached
Bank 1 mixture adaptation area 1 lower Richness limit exceeded
Malfunction in cooling system
Evaporative emissions canister purge regulator vale short circuit to ground
Secondary air injection pump relay short circuit to ground
Evaporative emission control leak detection pump short circuit to ground


After all of these " Short to ground " I went and checked the grounds I know of * under battery trunk etc * a problem the car was also having was when I would step on the Brakes the headlight would come on and the dash lights would come on, thus cars would get mad thinking I was flashing lights at them ( problem fixed by a lose ground in the trunk THANK GOODNESS )

Any help is GREATLY APPRECIATED in advance as I seem to be stuck at this point...

:confused:
 

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First, what is the history on this car? Was it sitting a long time?

Have you checked the charging Voltage? Make sure it does not go above 14.5 Volts.

Have you pulled the front dash to look at the ECU wiring? Check to make sure you have not had rodents nesting in the cowl and chewing wires.

Search YouTube for New Beetle Cabin Air Filter replacement, it is actually not hard to pull the front dash panels and lower access panels/

You may have a damaged ECU ground wire? Make sure the grounds around the ECY are all in good shape.
 

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Discussion Starter · #3 ·
First, what is the history on this car? Was it sitting a long time?

Have you checked the charging Voltage? Make sure it does not go above 14.5 Volts.

Have you pulled the front dash to look at the ECU wiring? Check to make sure you have not had rodents nesting in the cowl and chewing wires.

Search YouTube for New Beetle Cabin Air Filter replacement, it is actually not hard to pull the front dash panels and lower access panels/

You may have a damaged ECU ground wire? Make sure the grounds around the ECY are all in good shape.
I have owned the car maybe 6 months and it was fine the first 3 months then this problem arose, I have replaced the cabin airfilter and at same time we took out the what felt like bag of leaves. I inspected both of the ground connectors that are under the cabin air and one to the left of the ECU.

The car is a daily driver so it never sat since owning it, daily miles approx. 15-20

the car is worse in the mornings once its been started, say lunch time it doesn't shake as bad however it still lacks power when I try to accelerate at times, other times its ok...

this has me at a loss...
 

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Too many codes and most all of them have a common factor of short circuit to ground.

Clear codes and see what ones come back first.

I wonder if for some reason the ECU is bad?

The only other thing I can think of is the heated O2 sensors have a common ground that comes back to the ECU and if the heater wires short, it can burn up the ECU ground, but usually this causes the throttle not to work?

Might be worth trying to open up the ECU and inspect it if it is not fully sealed up?
 

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All those things with "short to ground" get their power through the fuel pump relay. That is the one thing they all have in common. After the relay they go through fuse 32 (the injectors) or fuse 43 (the other things). You could pull those fuses and make sure the voltage on the fuse terminal is good with key on/engine off.

The other thing I would check is the fuse panel on top of the battery. Make sure all connections are good including the cable from the fuse panel to the battery. Loose connections here can cause voltage surges in the electrical system.
 

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All those things with "short to ground" get their power through the fuel pump relay. That is the one thing they all have in common. After the relay they go through fuse 32 (the injectors) or fuse 43 (the other things). You could pull those fuses and make sure the voltage on the fuse terminal is good with key on/engine off.

The other thing I would check is the fuse panel on top of the battery. Make sure all connections are good including the cable from the fuse panel to the battery. Loose connections here can cause voltage surges in the electrical system.

Red: I seem to remember someone having an issue with the ground strap/connection under the battery tray. If memory serves? It was a primary ground that was badly goobered up with gunk. Might be worth a shot to check the fuse box and remove the battery and tray and see if that ground cable is roached? (Then again I may be totally off base? But it's all I got this morning)

S-
 

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There have been problems with that main ground connection but if I recall the symptoms were with the dash and controls in the interior, not the engine specifically as in this case. I'm working on a method to test the grounds in the car using a voltmeter that won't require taking anything apart.

All the items in the "short to ground" list get their power through the fuel pump relay and are grounded by the ECU to toggle them on and off. The "short to ground" message probably means that the ECU has detected that no current flows through the device (or too low a current) when the ECU tries to turn it on. That could mean excessive resistance in the fuel pump relay that causes the voltage to all the devices get too low when several are on at the same time. From the ECU's perspective it is as if the device had been shorted to ground since no current (or inadequate current) flows.

The toggling of the "shake" of the engine that the OP reports could be caused by a high-current device like the O2 sensor heating element toggling on and off. When the heater switches on the voltage on everything past the fuel pump relay, including the fuel injectors, suddenly goes low. The heating element shuts off and everything is good again. The O2 sensor heating element would be on mostly right after startup and cause the starting issues reported.
 

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I have an electronic Bentley VW manual which is a PITA to follow for electrical diagrams, add this on top of the way Bentley does the VW wiring diagrams are just hard to follow.

But does the VW have an "unloader" relay?

I know BMW has a relay they refer to an "unloader" relay that supplies 12 Volts to the fuel injectors and other components.

So if the fuel pump relay does not act this way, maybe there is another relay like the "unloader" relay that BMW uses?

I wonder if this problem is as simple as the small pigtail wire that connects to the battery is loose or a bad fuse box on top of the battery?
 

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I believe that what you are referring to is generally known as a "load reduction relay." Translated from German it may become "unloader." Those cut power to high-draw items like headlights, defogger, heated seats and such while the engine cranks. The fuel injectors definitely wouldn't be included!

The Bentley manual for 1999 shows the fuel injectors getting power through the fuel pump relay as well as those other items (O2 sensors, secondary air, ect.). Once you get use to those VW wiring diagrams they make sense. You just have to learn to think like a German!
 
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