ECM POWER SOURCE CIRCUIT

Transcription

1 050 SFI SYSTEM (UZFE) 059UU0 ECM POWER SOURCE CIRCUIT CIRCUIT DESCRIPTION When the ignition switch is turned ON, battery positive voltage is applied to terminal IGSW of the ECM and the EFI relay (Marking: EFI) control circuit in the ECM sends a signal to terminal MREL of the ECM switching on the EFI relay. This signal causes current to flow to the coil, closing the contacts of the EFI relay and supplying power to terminal + of the ECM. If the ignition switch is turned off, the ECM continues to switch on the EFI relay for a maximum of seconds for the initial setting of the throttle valve. WIRI DIAGRAM R I8 Ignition Switch R 7 AM IG 6 L 6 D Driver Side J/ IGN J O J8 WG O J3 C7 IC4 J3 O WG 9 8 ECM IGSW MREL + AM EFI EFI Relay 5 3 A C J3 J3 R E attery Engine Room R/ W J W C3 IC4 R J6 E EF A

2 SFI SYSTEM (UZFE) 0503 INSPECTION PROCEDURE INSPECT ECM(+ VOLTAGE) E () + (+) Measure the voltage between terminals of the and + () E () 9 4 V PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROLEM SYMPTOMS TALE (See page 059 ) CHECK HARNESS AND CONNECTOR(ECM ODY GROUND) Disconnect the ECM connector. Check the continuity between the wire harness side connectors. E E () ody ground A54408 REPAIR OR REPLACE HARNESS OR CONNECTOR 3 INSPECT ECM(IGSW VOLTAGE) E () IGSW (+) Measure the voltage between terminals of the and IGSW (9) E () 9 4 V Go to step 6 38

3 0504 SFI SYSTEM (UZFE) 4 CHECK FUSE(IGN FUSE) Driver Side J/ Remove the IGN fuse from the driver side J/. Check the continuity of IGN fuse. IGN Fuse A789 CHECK FOR SHORT IN ALL HARNESS AND COMPONENTS CONNECTED IGN FUSE 5 INSPECT IGNITION OR STARTER SWITCH ASSY IG ACC AM ST Check continuity between the connector terminals shown in the chart below. ST Switch position Terminal No. LOCK All terminal to terminal No continuity ACC 3 AM IG A58559 ON START REPLACE IGNITION OR STARTER SWITCH ASSY CHECK AND REPAIR HARNESS AND CONNECTOR (ATTERY IGNITION SWITCH, IGNITION SWITCH ECM) 6 INSPECT ECM(MREL VOLTAGE) E () MREL (+) Measure the voltage between terminals of the and MREL (8) E () 9 4 V CHECK AND REPLACE ECM (See page 035 ) 38

4 SFI SYSTEM (UZFE) CHECK FUSE(EFI FUSE) Engine Room R/ EFI fuse Remove the EFI fuse from the engine room R/. Check the continuity of EFI fuse. A788 CHECK FOR SHORT IN ALL HARNESS AND COMPONENTS CONNECTED EFI FUSE 8 INSPECT EFI RELAY Remove the EFI relay from the engine room R/. Inspect the EFI relay. Terminal No. Condition Constant Usually 3 5 Apply + between Terminals and No 600 REPLACE EFI RELAY 9 CHECK HARNESS AND CONNECTOR(EFI RELAY ECM, EFI RELAY ODY GROUND) Engine Room R/ Check the harness and connector between the EFI relay and ECM connector. () Remove the EFI relay from the engine room R/. () Disconnect the ECM connector. (3) Check the continuity between the wire harness side connectors. EFI Relay A669 EFI relay () MREL (8) Standard (Check for short): Wire Harness Side MREL EFI relay () or MREL (8) ody ground No continuity A

5 0506 SFI SYSTEM (UZFE) Check the harness and connector between the EFI relay and body ground. () Remove the EFI relay from the engine room R/. () Check the continuity between the wire harness side connector and body ground. EFI relay () ody ground REPAIR OR REPLACE HARNESS OR CONNECTOR CHECK AND REPAIR HARNESS AND CONNECTOR (TERMINAL + OF ECM ATTERY POS ITIVE TERMINAL) 384