1g contstant voltage OBD I

[gijoe985]

Well I went to check a car that the person said had a bad fuel pump. I checked the voltage between the #1 &12 pins of the OBD I connector. I got a constant voltage. I believe that is an ECU problem correct? I also checked for voltage at the pump with the key in the on position and I got 10.5 volts. When I turned the key from off to run I didn't hear anything from the pump, does this method work on a DSM? I listened from the back of the car just above the pump and didn't hear anything.

I guess that doesn't matter sine I got the continuous voltage from the code reader. Any thoughts?

 

[absolute_DSM]

More than likely the ECU. Just like everyone else has told you in your other posts.

 

[steve]

I also checked for voltage at the pump with the key in the on position and I got 10.5 volts. When I turned the key from off to run I didn't hear anything from the pump, does this method work on a DSM? I listened from the back of the car just above the pump and didn't hear anything.

You shouldn't have any voltage on the power wire (larger Black/White wire) to the pump until you are cranking the engine. The fuel pump doesn't run with just the ignition on for safety reasons. The other wires in the same connector by the pump are the gauge and warning light senders are will have voltage on them with the ignition switch on.