DI448 DIAGNOSTICS EINE (5VZFE) DI8Z003 Fuel Pump Control Circuit CIRCUIT DESCRIPTI In the diagram below, when the engine is cranked, current flows from terminal ST of the ignition switch to the starter relay coil and also current flows to terminal STA of the ECM (STA signal). When the STA signal and NE signal are input to the ECM, Tr is turned on, current flows to the coil of the circuit opening relay, the relay switches on, power is supplied to the fuel pump and the fuel pump operates. While the NE signal is generated (engine running), the ECM keeps Tr on (circuit opening relay on) and the fuel pump also keeps operating. IG Switch IG ST IGN EFI Relay GAUGE Circuit Opening Relay Fuel Pump ALT AM1 AM2 STARTER Relay Clutch Start Cancel Switch ECM EFI Battery Clutch Start Switch (M/T) Park/Neutral Position Switch (A/T) Starter From Crankshaft Position Sensor (STA Signal) STA (NE Signal) NE A00291 710
DIAGNOSTICS EINE (5VZFE) DI449 WIRI DIAGRAM WR 2 1 2 2 BR 6 7 I14 Ignition Switch AM2 W Battery 4 1I R/B No. 2 J/B No. 1 IGN J/B No. 3 11 1F 4 1 7 C6 Circuit Opening Relay BW 1 2 WR L 5 3 3E 3E IF1 WR WR From Terminal 3 of EFI Main Relay (See page DI443) 5 BN7 13 4 5 BN7 IG L WB WB WL 22 E5 F8 Fuel Pump ECM E01 A18651 INSPECTI PROCEDURE Handheld tester: 1 Check operation of fuel pump. BE6653 A00023 Fuel Inlet Hose A00127 PREPARATI: (a) Connect the handheld tester to the DLC3. (b) Turn the ignition switch and push the handheld tester main switch. (c) Select the item DIAGNOSIS/ENHANCED OBD II/AC- TIVE TEST/FUEL PUMP/SPD. Check for the fuel pressure in the fuel inlet hose when it is pinched by hand. : There is pressure in the fuel inlet hose. HINT: At this time, you will hear a fuel flowing noise. 711
DI450 DIAGNOSTICS EINE (5VZFE) 2 Check fuel pump (See page SF5). Replace fuel pump. 3 Check circuit opening relay (See page SF47). Replace circuit opening relay. 4 Check for open in harness and connector between circuit opening relay and fuel pump, and fuel pump and body ground (See page IN28). 5 Check voltage between terminal of ECM and body ground. () (+) PREPARATI: (a) Remove the glove compartment (See page SF63). (b) Turn the ignition switch. Measure the voltage between terminal of the ECM connector and the body ground. : Voltage: 9 14 V A15326 712
DIAGNOSTICS EINE (5VZFE) DI451 6 Check for open in harness and connector between circuit opening relay and ECM (See page IN28). Check and replace ECM (See page IN28). OBD II scan tool (excluding handheld tester): 1 Check operation of fuel pump. Fuel Return Hose PREPARATI: (a) Remove the glove compartment (See page SF63). (b) Turn the ignition switch. (a) Connect terminal of the ECM connector and the body ground. (b) Check for the fuel pressure in the inlet hose when it is pinched by hand. : There is pressure in the fuel inlet hose. HINT: At this time, you will hear a fuel flowing noise. A19862 A20027 713
DI452 DIAGNOSTICS EINE (5VZFE) 2 Check fuel pump (See page SF5). Replace fuel pump. 3 Check circuit opening relay (See page SF47). Replace circuit opening relay. 4 Check for open in harness and connector between circuit opening relay and fuel pump, and fuel pump and body ground (See page IN28). 5 Check voltage between terminal of ECM connector and body ground. () (+) PREPARATI: (a) Remove the glove compartment (See page SF63). (b) Turn the ignition switch. Measure the voltage between terminal of the ECM connector and the body ground. : Voltage: 9 14 V A15326 714
DIAGNOSTICS EINE (5VZFE) DI453 6 Check for open in harness and connector between circuit opening relay and ECM (See page IN28). Check and replace ECM (See page IN28). 715