Testing if a Fuel Pump is Bad Volkswagen Passat (1998 – 2005)

By | November 29, 2017

Testing if a Fuel Pump is Good or Bad 2004 Volkswagen Passat (1998 thru 2005)
Recently a friend had a fuel pump problem on a 2004 Passat. At first I was ready to simply swap in a new one until I seen the price, 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.
 




 
This 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 first thing to do is get access to the fuel pump which is in the trunk. There are three screws to remove with a Phillips screw driver.
Testing if a Fuel Pump is Good or Bad 2004 Volkswagen Passat
 
Locate the Fuel Pump plug and remove it.
Fuel Pump Location Volkswagen Passat
 
The fuel pump needs to get the correct voltages or it wont work.
 
Pins 1 and 4 on the plug (outer pins) are tested with a multi meter set to DC voltage.
Fuel Pump is Good or Bad 2004 Volkswagen Passat
 
Another person will need to turn the key to accessory than to start while you are watching the meter.
Volkswagen Passat Fuel Pump Wiring Voltage
 
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 relay or in the wiring going to the fuel pump.
 
Here is a video I made showing how its done.

 
How to Test The Fuel Pump Itself
The plug should be off the fuel pump and leads exposed.
 
Set a multi meter to read resistance (200 Ohms).
Volkswagen Passat Fuel Pump Testing if bad or good setting meter
 
Pins 1 and 4 on the fuel pump are the contacts to test resistance on.
Volkswagen Passat Fuel Pump Testing if bad pins 1 and 4
 
0 resistance = Bad fuel pump
1-3 ohms = Good fuel pump
High resistance = Bad fuel pump
 
Here is a fuel pump that has just been replaced and is good reading 2.7 ohms.
Volkswagen Passat Fuel Pump Test 2004
 
Here is a video I made showing how to test the fuel pump.

 
 
Replacing The Fuel Pump
A special removal tool is supposed to be used with Volkswagen fuel pumps to remove them.
 
Here is the special tool on Amazon
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.
 
Summary
Hopefully if you have a problem with a fuel pump in a Volkswagen Passat this will help you out.
 
I did save a lot of money doing it myself as a garage would have charged at least $700-$800 to do a swap out.
 
Here is the Fuel Pump on Amazon
Bosch 69733 Original Equipment Replacement Electric Fuel Pump

10 thoughts on “Testing if a Fuel Pump is Bad Volkswagen Passat (1998 – 2005)

  1. Wade

    how high of resistance are we talking if the fuel pump is bad? My ohm meter is working as I tested on some other resistors and when I check the pump I’m getting like 1300 ohms. this seems super odd.

    Reply
  2. Bill

    Very informative thank you, leads 1-4 reads 1.6 Oms you say above 1.3 is bad fuel pump so is this reading a bad fuel pump for sure?

    Bill

    Reply
  3. Dan

    Good write up. How has the bosch pump been for you? Im trying to decide between the bosch and the VW one. This one lasted 130k so the extra price may be worth it for the genuine part.

    Reply
  4. DAVID U MORALES

    Awesome very informative but just a little fyi, the link you place for the wrench tool is missing. The link goes in to a blank page

    Reply

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