Here is some info I'm throwing out there. Any Ideas are appreciated. Thanks!
If you do not repair the cause of the DTC, you can erase it until the cows come home and it will keep resetting until you do make the necessary repairs.
Diagnostic Trouble Code (DTC) 543 indicates a fuel pump secondary circuit failure between the B(+) supply and the Fuel Pump Monitor (FPM) connection to the power-to-pump circuit. 99 times out of 100, this DTC results in a no-start condition.
If the engine starts and runs, the it is a pretty good indication there is a problem with the Powertrain Control Module (PCM). NOTE: Due to the internal circuitry of the Powertrain Control Module (PCM), a left/front Heated Oxygen Sensor (HO2S) signal short to power could produce a Diagnostic Trouble Code (DTC) 542 or 543.
Tuesday, March 13th, 2012 AT 1:30 AM