fuel pump secondary circut low P0231

[Truckie117]

Hey anyone have this show up on OBDII scanner cleared it and came back. what does it mean

[wfyehl]

Hey anyone have this show up on OBDII scanner cleared it and came back. what does it mean


I actually had this on my Sub for about a year. I attempted to trace it down, and couldn't figure it out. I had to take the Sub into the Stealership for another issue, and they insisted on fixing it (actually fixed things before asking - but that's another story). First they thought it was my lift pump, so they changed it out with the oil pressure sensor (I already changed those out 9 and 6 months prior). Code came back. It turned out, after two more trips back, that it was a bad connector in the fuse panel on the drivers side in the engine compartment for the fuel pump relay. Once they R&R'd it, the code never came back. I'm not sure if they replaced the connector, pins, or just cleaned and adjusted the connections. I didn't ask anymore, I was glad that it was fixed even though they weren't authorized to fix anything in the first place.

Hope that helps,
Bill

[Truckie117]

got an odbII scanner and thats what it said secondary pump [lift pump]
i just installed a veggie oil kit and cut the lift pump out when the veggie pump is running thats the problem cause computer cks lift pump periodicly
Thanks mike

[john8662]

I replaced the fuel pump relay on my '96 and it went away and stayed away. I had jumped the connections when removing the relay to prime a fuel filter. Got butter fingers and dropped the solenoid on the shop floor, I guess the dropping did it in. A new one fixed it up.

Great advice on the connectors, could very well be.

J

[gmctd]

Put a relay in the lift pump ckt, connect the LP thru the relay contacts.

When the veggie circuit is on and lift pump is off, PCM will still read correct secondary circuit voltage thru the relay coil.