No Start:
- Inertia switch not reset or electrically open.
- Open circuit in or between ECA and fuel pump.
- Faulty ground connection at fuel pump.
If engine starts, go to step 21). If engine does not start, go to step 24).
21) Check Fuel Pump Operation Turn ignition on. Wait 5 seconds. Listen for fuel pump operation. If fuel pump is off, go to step 23). If fuel pump is on, go to step 22).
22) Check For Fuel Pump Relay Always Closed Turn ignition off. Disconnect fuel pump relay. Turn ignition on. If fuel pump is off with relay disconnected, replace fuel pump relay and repeat QUICK TEST . If fuel pump is on with relay disconnected, repair short to power in POWER-TO-PUMP/FPM circuit. (For models with relay block, also check fuel pump prime plug circuit). Repeat QUICK TEST.
23) Check Continuity Of Fuel Pump Monitor (FPM) Circuit Turn ignition off. Disconnect ECA 60-pin connector. Inspect and repair any damaged terminals. Install EEC-IV Breakout Box (T83L-50-EEC-IV), leaving ECA disconnected. Disconnect fuel pump relay. Measure resistance between test pin No. 8 (No. 19 on Escort, Mustang and Tracer) at breakout box and POWER-TO-PUMP circuit at fuel pump relay wiring harness connector. If resistance is less than 5 ohms, go to step 35) (dual HEGO) or replace ECA and repeat QUICK TEST (single HEGO). If resistance is 5 ohms or more, repair open circuit and repeat QUICK TEST.
24) Check Inertia Switch Turn ignition off. Disconnect fuel pump inertia switch. Ensure switch is reset. Measure resistance of inertia switch (between GND pin and FP pin on Escort and Tracer). See Fig 1 . If resistance is less than 5 ohms, reconnect switch and check for open in POWER-TO-PUMP circuit, poor fuel pump ground or open in fuel pump. If resistance is 5 ohms or more, reset or replace inertia switch. Repeat QUICK TEST .
30) Code 96/543 Code 96/543 indicates fuel pump secondary circuit failure between BATT (+) supply and FPM connection to POWER-TO-PUMP circuit. Following are possible causes: