2001.5 Volkswagen Passat Cranks No Start

VOLKSWAGEN
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AUDIDUDI
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  • 2 POSTS
OK… So I was huge rush, trying to multitask several things and unfortunately I wasn’t really paying attention to what I was doing. In the hopes of saving time, I made a really stupid mistake and it kills me because I knew better. I charged the batter in my wife’s Passat. The problem is I didn’t bother to remove the batter or disconnect the leads. The engine will crank but will not start. I don’t think I’m getting a spark but I’m not sure. Do you think I fried the ECU or do you think it’s something else?

2001.5 Passat 2.8 Wagon
a little over 100K mi

Many Thanks,
John
Mar 21, 2006 at 2:45 AM
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LOSONE
  • ✓Experienced Mechanic
  • 1,616 POSTS
1st check all the fuses!!

Check the group of brown wires attached to the body on the iorewall. Remove the clump and clean the body connection.

Make sure the small wires from the battery + terminal have a good connection.

Remove the coil wire from the distributer and hold it against metal while someone turns the car over. If you have spark then check and see if you are getting fuel. I doubt if you fried the ECU as they are bullet proof. No spark probably the ignition module.

The fuel pump is external to the tank on the drivers side. there are two round/square looking objects one is the fuel filter and the other the fuel pump. Have someone turn the engine over while you put your hand on the fuel pump. You can feel it running. If it isn't running tap it gentle with a small metal object and see if it starts running. Sometimes VW fuel pumps get set on a noid and won't run.

DO NOT MESS WITH THE FUEL INJECTION DISTRIBUTION HEAD UNDER THE AIR CLEANER!!

Get back to me and let me know what you found. Good Luck
Mar 30, 2006 at 2:50 AM
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AUDIDUDI
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Thanks for the info... I'll give it a try this weekend and get back to you. I did check all the fuses located at the end of the dashboard on driveer side and they are all ok.

Thanks again,
John
Mar 30, 2006 at 4:50 AM
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Suggested Repair

Check the fuses, clean the brown ground-wire connection on the firewall, and confirm the small positive battery wires are secure. Test for spark at the coil wire; no spark is more likely an ignition module than a failed ECU. If spark is present, check whether the external driver-side fuel pump runs while cranking and tap it gently if it does not. Do not disturb the fuel-injection distribution head under the air cleaner.

Conversation Summary

The owner of a 2001.5 Volkswagen Passat 2.8 wagon charged the battery without disconnecting it. The engine cranks but will not start, and the owner suspects no spark and possible ECU damage. Dashboard fuses were already checked and found good. The expert advised cleaning the firewall ground connection, verifying battery wiring, testing for spark and fuel, and checking the external fuel pump, while saying the ECU is unlikely to be damaged.

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