I have a friend who was having a fuel pump problem on a 2004 Passat, so I went over to help troubleshoot.
At first I was ready to simply swap in a new one until I seen the price, which would make it costly if it was not the problem.
Plus, a special tool is needed to push it in and out, so I wanted to be sure the fuel pump was bad before swapping in a new one.
After reading online in various forums, I found this can be done with a multi meter and another person to turn the car ignition.
Testing The Fuel Pump is a Two Step Process.
- First, we want to be sure the correct voltage is being sent to the pump.
- Second, we will test the fuel pump itself.
The fuel pump needs to get the correct voltages, or it won’t work.
This is what the voltages should read at the plug wiring harness.
- With the key in accessory, it should read 3-4 volts DC.
- When the car is cranked on and trying to start, it should read 11-12 volts DC.
If you do not get the above voltages than most likely a problem is in a fuse, relay, or in the wiring going to the fuel pump.
How to Test The Fuel Pump VW Passat (1998-2005)
The plug should be off the fuel pump and leads exposed.
- 0 resistance = Bad fuel pump
- 1-3 ohms = Good fuel pump
- High resistance = Bad fuel pump
Replacing The Fuel Pump In a VW Passat (1998-2005)
Replacing the fuel pump is not hugely difficult as long as you have the correct tools.
A special removal tool is supposed to be used with Volkswagen fuel pumps to remove them.
Here is the special tool on Amazon (Paid Affiliate Link)
Baum Tools 3307 Volkswagen and Audi Gas Fuel Pump Removal and Installation Wrench
I didn’t know a special tool was needed and only found out after the pump I ordered came in.
After playing with it for 2-3 hours hands covered in gas I finally got it in without the tool.
If I ever have to do it over, I would definitely order the tool as I did almost break it trying to get it in.
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