brucej455

can't figure out a way to eliminate bad ign sw. Have jumpered 30 to 87 and still pump will not run. where does pump get grnd

geo1

Pump gets ground on frame,near tank

brucej455

yes found that wire it was clean but spruced it up have no batt on relay coil wire so that when pcm gives ground it activates pump relay. I don't have wiring schematics so what gives terminal xx battery ? pcm or ign sw?

a55bruce

The ECM (Engine Control Module) provides the 12V to activate the fuel pump relay.

geo1

So,jumping 30 to 87,no pump,that truck has a fscm,between relay and pump, but where is it on tahoe?

geo1

Looked into it more,some have return line,2 line system, some have 1 line,fscm involved,just looked at 07,2 line

brucej455

know most abbreviations but do not know fcsm. could you tell me what4 that stands for
thanks Bruce

geo1

Fuel system control module,so I took a look,07 Tahoe that I got under,is 3 line pipe system,no fscm,so what do you have,new 1 pipe system,no return?or 2 pipe,with return and pressure regulator on intake