Test J - Fuel Pump CKT (Relay & Inertia Switch): Notes

NOTE: Perform this test when Service Code 87, 95, or 96 is displayed during QUICK TESTS or when directed here by other test procedures.

NOTE: This test is intended to diagnose only the following:

Fuel Pump Relay
Inertia Switch
Harness Circuits (Batt +, VPWR, FUEL PUMP, GND, POWER-to-PUMP)
ECA

TEST PIN NO. 22 IDENTIFICATION

Application (Test Pin No.)	Wire Color
Pin 22: All Models	Tan/Light Green
Pin 8, 19 or 50, Power-to-Pump: All Models	Pink/Black
Batt (+) Ckt: 3.0L PFI (Aerostar)	Yellow
Pin 37 or 57: All Models	Red

Fig 1: 3.0L Fuel Pump Ckt Diagram

1) No Fuel Pump Pressure: Check Fuel Pump Electrical Operation Turn key from OFF to RUN position several times (DO NOT turn to START position). If fuel pumps run briefly each time key is turned to RUN position, fuel pump circuit is okay. If not, go to next step.

2) Check For VPWR to ECA With key off, install breakout box and reconnect ECA. Set DVOM on 20-volt scale. Turn key on, leaving engine off. Measure voltage between test pins No. 37 and 40 at the breakout box. Measure voltage between test pins No. 57 and 60 at the breakout box. If both voltage readings are greater than 10.5 volts, go to step 5). If voltage is not greater than 10.5 volts, go to TEST B, step 1).

NOTE: There is a break in the step numbering sequence at this point, skipping from step 2) to step 5). Break is due to previous chart references to these testing procedures. No test procedures have been omitted.

5) Check Voltage to POWER-to-PUMP Circuit With KOEO, breakout box installed and ECA connected, set DVOM on 20-volt scale. Measure voltage between chassis ground and POWER-to-PUMP circuit at fuel pump relay while cranking engine. If reading is less than 8 volts, go to step 6). If reading is 8 volts or more, check the following: open in POWER-to-PUMP circuit, open in fuel pump and open fuel pump ground circuit.

6) Checking BATT (+) Circuit to Fuel Pump Relay Turn key on, leaving engine off. Leave breakout box installed and ECA connected. Locate fuel pump relay. Set DVOM on 20-volt scale. Measure voltage between chassis ground and BATT (+) circuit at fuel pump relay. If reading is less than 10.5 volts, repair open in BATT (+) circuit between fuel pump relay and battery positive post. Repeat QUICK TEST. If reading is 10.5 volts or greater, go to step 11).

7) Code 87: Checking VPWR Circuit to Fuel Pump Relay Code 87 indicates a fuel pump primary circuit failure. Possible causes for this fault are: inertia switch not reset or electrically open, faulty fuel pump relay or ECA. Open or shorted circuit. Turn key on, leaving engine off. Leave breakout box installed and ECA connected. Locate fuel pump relay. Set DVOM on 20-volt scale. Measure voltage between chassis ground and VPWR circuit at fuel pump relay. If reading is 10.5 volts or more, go to next step. If reading is less than 10.5 volts, ensure inertia switch is on. If inertia switch will not reset, replace switch. If switch is okay, repair open in VPWR circuit between EEC power relay and fuel pump relay. Repeat QUICK TEST.

8) Check FUEL PUMP Circuit Continuity Turn key off and wait 10 seconds. Disconnect ECA 60-pin connector. Inspect for corroded or damaged connector pins and repair as necessary. Install breakout box, leaving ECA disconnected. With DVOM on 200-ohm scale, measure resistance between FUEL PUMP circuit at pump relay and test pin No. 22 at breakout box. If reading is 5 ohms or more, repair open in FUEL PUMP circuit. Repeat QUICK TEST. If reading is less than 5 ohms, go to next step.

9) Check For Short to Power With key off, disconnect ECA and fuel pump relay. Install breakout box and set DVOM on 20-volt scale. Turn key on. Measure voltage between test pin No. 22 and battery negative terminal. If voltage is less than one volt, go to next step. If not, repair short circuit. Reconnect ECA and attempt to start vehicle. If vehicle fails to start, replace ECA. Rerun QUICK TEST.

10) Check For Shorts to Ground Turn key off and wait 10 seconds. Leave breakout box installed and ECA disconnected. Disconnect fuel pump relay. With DVOM on 200-k/ohm scale, measure resistance between test pin No. 22 and test pins No. 40 and 60. If reading is less than 10 k/ohms, repair short in FUEL PUMP circuit. Repeat QUICK TEST. If reading is 10 k/ohms or more, go to next step.

11) Check Voltage at POWER-to-PUMP Circuit Turn key off. Leave breakout box installed and ECA disconnected. Install a jumper wire between test pin No. 22 and test pins No. 40 or 60. Set DVOM on 20-volt scale. With KOEO, measure voltage between chassis ground and POWER-to-PUMP circuit at fuel pump relay. If reading is 10.5 volts or more, replace ECA and repeat QUICK TEST. If reading is less than 10.5 volts, replace fuel pump relay. Connect ECA and repeat QUICK TEST.

NOTE: There is a break in the step numbering sequence at this point, skipping from step 11) to step 20). Break is due to previous chart references to these testing procedures. No test procedures have been omitted.

20) Code 95: Does Engine Start? A KOEO Code 95 indicates that one of the following has occurred: