2002 Tahoe cranks but wont start


#1

Hi,
My 2002 Tahoe cranks over fine (new battery), but, will not start. I have checked the fuel pump relay and have control power to energize the relay, but. no switched power from ECM to change relay state. Jumped rely 30/87 and pump runs. No DTC’s. Gauge on instrument panel reads no fuel. Scanner shows 56% level. Tried to use my Snapon MT2500 to switch relay state and received error message “generic device control limit exceeded” ECM?
Thanks


#2

Have you checked for a bad crank sensor?

When the ignition is turned on, the ECM will power the fuel pump relay for a second or two to prime the fuel system and then cut power to the relay.

When the engine is started, ECM needs to see crankshaft rotation. Otherwise the ECM see’s no reason to operate the fuel pump.

Tester


#3

Tester,

Not getting the prime signal from ECM. Gauge also reads empty on instrument panel though scan tool shows 56% level (2 volts).

Jumped the relay at the electrical panel and got 60 psi from pump.

Thouhts?

Thanks


#4

Gauge and logic are all through the PCM.