Note On Intermittents

WARNING: This page is about a different car, the 1995 Cadillac DeVille. However, it is still accessible from the selected car via links, so may be relevant.

Backprobe PCM terminal 3E13 using a voltmeter to ground. Turn ignition on and observe voltmeter. Voltmeter should indicate battery voltage for 2 seconds and then drop to zero. If voltage reading stays at battery voltage for longer than 2 seconds, check for sticking fuel pump relay contacts. Repeat test several times. Continue backprobing PCM terminal 3E13. Start and turn off engine. Voltage should immediately drop to zero. If voltage does not immediately drop to zero, check for sticking oil pressure switch contacts. Check for bent relay terminals or C101 terminals that may be contacting each other causing 12 volts on circuit No. 120.

Fig 1: Code P019 Schematic, Shorted Fuel Pump Circuit

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code P019 Diagnostic Flow Chart, Shorted Fuel Pump Circuit

Courtesy of GENERAL MOTORS CORP.