Hard Trouble Code E19: Notes

NOTE: If this code is not displayed during second pass of diagnostic codes, it is an intermittent failure and cannot be diagnosed using this procedure.

When ignition is turned on, ECM energizes fuel pump relay for 2 seconds which feeds 12 volts to fuel pump circuit (No. 120). Unless distributor reference pulses are received within this time, ECM will de-energize relay so that fuel pump does not continue to run at ignition on.

Trouble code indicates that fuel pump relay circuit continues to have 12 volts on it after 2 second fuel pressure prime. Voltage is read by ECM on fuel pump feedback input (circuit No. 120). This is also voltage which is displayed on engine data parameter P.1.0. Under conditions of code "E19", reading will be greater than 11 volts at ignition on (parameter P.1.0 reading is normally 0 volts at ignition on). Possible causes are: Faulty fuel pump relay, faulty oil pressure switch, defective wiring, terminals, etc., or ECM not processing fuel pump feedback voltage properly or not switching relay off.

NOTE: The following step numbers refer to the numbers in the accompanying flow chart(s).

If the unwanted source of voltage can be eliminated, then self-diagnostics can be used to detect this by displaying engine data parameter P.1.0. When voltage is removed from circuit, reading will drop to 0 volts. Begin eliminating branches of fuel pump circuit by removing oil pressure switch connector. If reading is now 0, oil pressure switch must be replaced because it is closing switch without receiving oil pressure.
If reading is still greater than 0 volts, another portion of fuel pump circuit can be eliminated by removing fuel pump relay. If reading is still greater than 0, circuit No. 120 must be inspected for a short to voltage. If voltage on circuit No. 120 is greater than 0 volts with ECM disconnected, circuit is shorted to voltage. If voltage is 0, fault must be in ECM connector or ECM itself.
If reading is now 0 after removing fuel pump relay, probe relay socket cavity No. 5 with test light to ground. After turning ignition on, test light should light for 2 seconds and then go out. If light does not go out, replace relay because it is failing to open.
If test light stays on, either ECM or wiring harness is shorted to voltage. If there is voltage on circuit No. 465 with ECM disconnected, circuit is shorted to voltage. If voltage is 0, check for faulty ECM connector or faulty ECM.