Fuel pump issues
October 11th, 2023, 9:51 PM
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Fuel pump issues
So I have a 2016 chevy express cutaway chassis with enclosed box. Truck has 40k. Truck wouldn't started randomly. Found bad fuel pump. Replaced fuel pump and had intermittent fuel pump running. The fuel pump relay has the following.
30- constant power 12.0v
86- constant ground
87- nothing but when jumping with power turns fuel pump on85- when key is on the first 2 seconds it is 12v then goes to 8.5-9.0v. If I turn key off it goes to 2v for about 5-10 seconds then to 0.
I removed the fuse block and checked behind for melted pins and nothing. Checked all fuses,relays and ground. No codes stored. Checked continuity of wire from pin 85 to ecm and .1 ohm of resistance. If I unplug the A1 connector and test directly at ecm I still get 9.0v with key on for pin 85. I checked my positive and ground to ecm and they are also good. I'm thinking a bad ecm which triggered the fuel pump to go. Anything else to look for before swapping ecms?
30- constant power 12.0v
86- constant ground
87- nothing but when jumping with power turns fuel pump on85- when key is on the first 2 seconds it is 12v then goes to 8.5-9.0v. If I turn key off it goes to 2v for about 5-10 seconds then to 0.
I removed the fuse block and checked behind for melted pins and nothing. Checked all fuses,relays and ground. No codes stored. Checked continuity of wire from pin 85 to ecm and .1 ohm of resistance. If I unplug the A1 connector and test directly at ecm I still get 9.0v with key on for pin 85. I checked my positive and ground to ecm and they are also good. I'm thinking a bad ecm which triggered the fuel pump to go. Anything else to look for before swapping ecms?
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mcessna1222
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