Powertrain Controls - ECM/PCM

DTC 19 Chart:

Fuel Pump Circuit:

Fuel Pump Relay Connector:

CIRCUIT DESCRIPTION
When the key is first turned "ON", the PCM turns the fuel pump control relay "ON" for two seconds to prime the fuel system for starting. If the engine is not cranked within two seconds of key "ON," the PCM turns "OFF" the fuel pump control relay until the engine is cranked. If the signal on the fuel pump feedback CKT 120 indicates that the fuel pump is "ON" when it should be "OFF," DTC 19 will set.

DTC 19 WILL SET WHEN
- DTCs 12, 14, and 15 are not set.
- The engine coolant temperature (ECT) is 50°C (12°F) or greater.
- No 4X fuel control pulses have been detected since key "ON" (engine has not been cranked).
- Fuel pump feedback voltage on CKT 120 is greater than 7 volts for 6 seconds after key "ON".

ACTION TAKEN (PCM WILL DEFAULT TO)
With a current DTC 19 set, the PCM will illuminate the Malfunction Indicator Lamp (MIL) (Service Engine Soon).

DTC 19 WILL CLEAR WHEN
The fault no longer exists and the ignition switch is cycled "OFF" and "ON".

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.

1. With the key "ON", engine "OFF", parameter "FP monitor" voltage should read 0 volts (fuel pump relay de-energized). If Tech 1 display shows voltage greater than 7 volts, the cause of voltage on CKT 120 must be repaired.
2. Checking for a shorted oil pressure switch.
2. Checking for 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.

DIAGNOSTIC AIDS
If when the ignition is turned "OFF" and the oil pressure telltale does not work properly, check for the oil pressure sensor intermittently stuck closed or a short to voltage on CKT 1042 keeping the fuel pump relays energized.