93 jetta gl
socalguy
02-12-2005, 03:31 AM
Need help in getting a second opinion regarding my diagnostic .Fuel pump is working fine based on direct test. Found out that no power goes to the fuel pump from the pump relay . Further test shows no ground supplies the coil inside the relay to activate the contacts.Would this be a case of a malfunctioning computer??? I got power on one side of the coil relay and power supply to the pump.Thanks
boschmann
02-13-2005, 06:14 PM
The ECM will only generate the ground to trigger the relay if it sees signal that the coil is firing. Do you get a spark when cranking? It should also ground for a couple of seconds when the key is first turned to on.
socalguy
02-13-2005, 07:10 PM
The ECM will only generate the ground to trigger the relay if it sees signal that the coil is firing. Do you get a spark when cranking? It should also ground for a couple of seconds when the key is first turned to on.
thanks Boschman for your reply . I can make the car run by bypassing the relay coil . I jump the 2 terminals that powers up fuel pump and the car runs.I got power from the relay coil but dont have ground on the other side .So my I think that the computer doesnt trigger any ground to to complete the circiut for the relay coil which will trigger the contacts to power the fuel pump.
thanks Boschman for your reply . I can make the car run by bypassing the relay coil . I jump the 2 terminals that powers up fuel pump and the car runs.I got power from the relay coil but dont have ground on the other side .So my I think that the computer doesnt trigger any ground to to complete the circiut for the relay coil which will trigger the contacts to power the fuel pump.
boschmann
02-15-2005, 04:26 PM
Before replacing the ECM you should check the continuity of the wire from the relay to the ECM. The ECM connection is at pin number six, yellow/blue wire. The connection at the back of the fusebox is at connector G1, pin #3.
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