2000 GMC Savana 5.7L with Code P1351: No Power to Fuel Pump Relay - Diagnosis and Fix
I own a 2000 GMC Savana 5.7L with Diagnostic Trouble Code P1351. When I attempt to start the vehicle without a jumper across the fuel pump terminals, it cranks properly, has strong spark, and shows 60 psi at the fuel rail—yet there is no power to the pull-in circuit of the fuel pump relay. With a jumper connected between the two terminals, the engine starts and runs normally with all gauges functioning. I suspect either a faulty sensor or a defective fuel pressure regulator might be preventing power from reaching the pull-in circuit of the fuel pump relay. However, I have already checked all fuses—both inside the driver’s kick panel and under the hood near the master brake cylinder—and found no issues. There is no power at the pull-in terminal (terminal 85) when the key is in the 'on' position, which is when the fuel pump should activate. The fuel pump relay has a gray wire connected to terminal 30 (always powered), an orange wire from ECM B fuse (under hood) to terminal 87, a black/white wire for constant ground at terminal 86, and a dark green/white wire receiving 12V control signal from the Vehicle Control Module (VCM) at terminal 85. The pump does not engage during initial key-on sequence. I replaced the relay with one designed for starter pull-in—this worked fine for starting—but did not resolve the issue. Only terminal 30 shows power. When I jumper terminals 30 and 87, the fuel pump activates, reaches 60 psi, and the engine starts successfully (though only briefly to avoid potential damage). I’ve tested with a multimeter: terminal 85 receives proper voltage when the key is turned on—indicating the VCM is sending power. The ground at terminal 86 shows zero resistance, confirming continuity. The final fix was discovering that the female terminals in the fuse box are not securely holding the male spade terminals of the relay. This poor connection prevents the pull-in signal from being properly transmitted. After reseating and securing all connections, the vehicle started and ran normally without any jumper. This issue highlights the importance of checking mechanical terminal fitment as well as electrical signals in fuel system diagnostics.
You mentioned that with the jumper removed, you still measure 60 psi at the fuel rail—correct? If so, does this indicate the fuel pump is already running properly?