P019

This article has been updated with bulletin No.: 51-65-10.

DTC PO19:

Fuel Pump Circuit:

DESCRIPTION
The Powertrain Control Module (PCM) monitors fuel pump feedback voltage for four seconds after the ignition is turned "ON" without the engine being cranked. The fuel pump relay will be energized for 2 seconds and then de-energized. If the voltage on the fuel pump feedback never drops below 7 volts during the first 4 seconds, Code P019 will set indicating voltage on CKT 120 with the fuel pump relay de-energized.

TEST CONDITIONS
1. Code P012 not set.
2. Engine coolant temperature 50°C or greater.
3. No distributor reference pulses detected since key "ON."

FAILURE CONDITIONS
Fuel pump feedback voltage remained above 7 volts for 4 seconds after ignition "ON" (fuel pump relay never de-energized)

ACTION TAKEN
PCM turns "ON" the "SERVICE VEHICLE SOON" Malfunction Indicator Lamp (MIL).

NOTES ON FAULT TREE
1. With the key "ON," engine "OFF" parameter PD10, battery voltage, should read 0 volt (fuel pump relay de-energized). If PD10 shows voltage greater than 7 volts, the cause of voltage on CKT 120 must be repaired.

2. Checking for a shorted oil pressure switch. A shorted oil pressure switch will cause a Code P019 to set.

3. Checking for a shorted fuel pump relay.

4. Checking for voltage on CKT 120 at the PCM.

5. Checking for proper control of the fuel pump relay by the PCM.

NOTES ON INTERMITTENTS
Back probe the PCM pin "3E13" with a voltmeter to ground. Key on and observe voltmeter - it should read battery voltage for 2 seconds then drop to 0 volt. If the voltmeter stays at battery voltage for longer than 2 seconds, check for fuel pump relay contacts sticking. Repeat the test several times. Continue back probing the PCM pin "3E13" with a voltmeter and start engine then key "OFF" voltage should drop immediately to 0. If it doesn't, check oil pressure switch for sticking contacts. Check for relay terminals or C101 terminals bent, contacting each other causing 12 volts on CKT 120.