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HOMESERVICE MANUALSTOYOTA20104 RUNNER 2WD L4-2.7L (2TR-FE)REPAIR AND DIAGNOSISPOWERTRAIN MANAGEMENTCOMPUTERS AND CONTROL SYSTEMSTESTING AND INSPECTIONCOMPONENT TESTS AND GENERAL DIAGNOSTICSECM POWER SOURCE CIRCUIT
2010 Toyota 4 Runner 2WD L4-2.7L (2TR-FE)
ECM Power Source Circuit
2010 Toyota 4 Runner 2WD L4-2.7L (2TR-FE)SECTION ECM Power Source Circuit
2TR-FE ENGINE CONTROL: SFI SYSTEM: ECM Power Source Circuit
- ECM Power Source Circuit
DESCRIPTION
When the ignition switch is turned to ON, battery voltage is applied to terminal IGSW of the ECM. The output signal from the MREL terminal of the ECM causes current to flow to the coil, closing the contacts of the integration relay (EFI MAIN relay) and supplying power to terminal +B of the ECM.
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
PROCEDURE
1. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND)
(a) Disconnect the ECM connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
(c) Reconnect the ECM connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - BODY GROUND)
OK -- Continue to next step.
2. INSPECT ECM (IGSW VOLTAGE)
(a) Disconnect the ECM connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Text in Illustration
(c) Reconnect the ECM connector.
NG -- INSPECT INTEGRATION RELAY (IG2 RELAY)
OK -- Continue to next step.
3. INSPECT INTEGRATION RELAY (EFI RELAY)
(a) Inspect the integration relay (EFI relay) Testing and Inspection.
NG -- REPLACE INTEGRATION RELAY (EFI RELAY)
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY [EFI RELAY] - ECM)
(a) Remove the integration relay (EFI relay) from the engine room relay block.
(b) Disconnect the integration relay connector.
(c) Disconnect the ECM connector.
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open):
Standard Resistance (Check for Short):
(e) Reconnect the ECM connector.
(f) Reconnect the integration relay connector.
(g) Reinstall the integration relay.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (INTEGRATION RELAY [EFI RELAY] - ECM)
OK -- Continue to next step.
5. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY [EFI RELAY] - BATTERY)
(a) Remove the integration relay (EFI relay) from the engine room relay block.
(b) Disconnect the integration relay connector.
(c) Disconnect the cable from the negative (-) battery terminal.
(d) Disconnect the cable from the positive (+) battery terminal.
(e) Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open):
Standard Resistance (Check for Short):
(f) Reconnect the integration relay connector.
(g) Reinstall the integration relay.
(h) Reconnect the cable to the positive (+) battery terminal.
(i) Reconnect the cable to the negative (-) battery terminal.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (INTEGRATION RELAY [EFI RELAY] - BATTERY)
OK -- Continue to next step.
6. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY [EFI RELAY] - BODY GROUND)
(a) Remove the integration relay (EFI relay) from the engine room relay block.
(b) Disconnect the integration relay connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
(d) Reconnect the integration relay connector.
(e) Reinstall the integration relay.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (INTEGRATION RELAY [EFI RELAY] - BODY GROUND)
OK -- Continue to next step.
7. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY [EFI RELAY] - ECM)
(a) Disconnect the ECM connector.
(b) Remove the integration relay (EFI relay) from the engine room relay block.
(c) Disconnect the integration relay connector.
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open):
Standard Resistance (Check for Short):
(e) Reconnect the ECM connector.
(f) Reconnect the integration relay connector.
(g) Reinstall the integration relay.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (INTEGRATION RELAY [EFI RELAY] - ECM)
OK -- REPLACE ECM Removal
8. INSPECT INTEGRATION RELAY (IG2 RELAY)
(a) Inspect the integration relay (IG2 relay) Testing and Inspection.
NG -- REPLACE INTEGRATION RELAY (IG2 RELAY)
OK -- Continue to next step.
9. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY [IG2 RELAY] - ECM)
(a) Disconnect the ECM connector.
(b) Remove the integration relay (IG2 relay) from the engine room relay block.
(c) Disconnect the integration relay connector.
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open):
Standard Resistance (Check for Short):
(e) Reconnect the ECM connector.
(f) Reconnect the integration relay connector.
(g) Reinstall the integration relay.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (INTEGRATION RELAY [IG2 RELAY] - ECM)
OK -- Continue to next step.
10. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY [IG2 RELAY] - BATTERY)
(a) Remove the integration relay (IG2 relay) from the engine room relay block.
(b) Disconnect the integration relay connector.
(c) Disconnect the cable from the negative (-) battery terminal.
(d) Disconnect the cable from the positive (+) battery terminal.
(e) Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open):
Standard Resistance (Check for Short):
(f) Reconnect the integration relay connector.
(g) Reinstall the integration relay.
(h) Reconnect the cable to the positive (+) battery terminal.
(i) Reconnect the cable to the negative (-) battery terminal.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (INTEGRATION RELAY [IG2 RELAY] - BATTERY)
OK -- Continue to next step.
11. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY [IG2 RELAY] - BODY GROUND)
(a) Remove the integration relay (IG2 relay) from the engine room relay block.
(b) Disconnect the integration relay connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
(d) Reconnect the integration relay connector.
(e) Reinstall the integration relay.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (INTEGRATION RELAY [IG2 RELAY] - BODY GROUND)
OK -- Continue to next step.
12. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY [IG2 RELAY] - IGNITION SWITCH)
(a) Disconnect the ignition switch connector.
(b) Remove the integration relay (IG2 relay) from the engine room relay block.
(c) Disconnect the integration relay connector.
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open):
Standard Resistance (Check for Short):
(e) Reconnect the ignition switch connector.
(f) Reconnect the integration relay connector.
(g) Reinstall the integration relay.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (INTEGRATION RELAY [IG2 RELAY] - IGNITION SWITCH)
OK -- Continue to next step.
13. INSPECT IGNITION SWITCH ASSEMBLY
(a) Inspect the ignition switch assembly Testing and Inspection.
NG -- REPLACE IGNITION SWITCH ASSEMBLY Removal
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (IGNITION SWITCH - BATTERY)
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.