Lexus NX: Fuel Injector Circuit
DESCRIPTION
The fuel injector assemblies are located on the intake port. They inject fuel into the cylinders based on the signals from the ECM.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
Inspect the fuses for circuits related to this system before performing the following procedure.
PROCEDURE
| 1. | CHECK TERMINAL VOLTAGE (POWER SOURCE OF FUEL INJECTOR ASSEMBLY) |
| *a | Front view of wire harness connector (to Fuel Injector Assembly) |
(a) Disconnect the fuel injector assembly connector.
(b) Turn the power switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| C36-1 - Body ground | Power switch on (IG) | 11 to 14 V |
| C35-1 - Body ground | Power switch on (IG) | 11 to 14 V |
| G1-1 - Body ground | Power switch on (IG) | 11 to 14 V |
| G2-1 - Body ground | Power switch on (IG) | 11 to 14 V |
| NG | .gif) | GO TO STEP 4 |
|
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| 2. | INSPECT FUEL INJECTOR ASSEMBLY |
(a) Inspect the fuel injector assembly.
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HINT:
Perform "Inspection After Repair" after replacing the fuel injector assembly.
Click here
| NG | | REPLACE FUEL INJECTOR ASSEMBLY |
|
| 3. | CHECK HARNESS AND CONNECTOR (FUEL INJECTOR ASSEMBLY - ECM) |
(a) Disconnect the fuel injector assembly connector.
(b) Disconnect the ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| C36-2 - C48-20 (#10) | Always | Below 1 Ω |
| C35-2 - C48-17 (#20) | Always | Below 1 Ω |
| G1-2 - C48-18 (#30) | Always | Below 1 Ω |
| G2-2 - C48-19 (#40) | Always | Below 1 Ω |
| C36-2 or C48-20 (#10) - Body ground | Always | 10 kΩ or higher |
| C35-2 or C48-17 (#20) - Body ground | Always | 10 kΩ or higher |
| G1-2 or C48-18 (#30) - Body ground | Always | 10 kΩ or higher |
| G2-2 or C48-19 (#40) - Body ground | Always | 10 kΩ or higher |
| OK | | PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
| 4. | CHECK HARNESS AND CONNECTOR (IG2-MAIN RELAY - FUEL INJECTOR ASSEMBLY) |
(a) Remove the IG2-MAIN relay from the No. 1 engine room relay block and junction block assembly.
(b) Disconnect the fuel injector assembly connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| 5 (IG2-MAIN relay) - C36-1 | Always | Below 1 Ω |
| 5 (IG2-MAIN relay) - C35-1 | Always | Below 1 Ω |
| 5 (IG2-MAIN relay) - G1-1 | Always | Below 1 Ω |
| 5 (IG2-MAIN relay) - G2-1 | Always | Below 1 Ω |
| 5 (IG2-MAIN relay) or C36-1 - Body ground | Always | 10 kΩ or higher |
| 5 (IG2-MAIN relay) or C35-1 - Body ground | Always | 10 kΩ or higher |
| 5 (IG2-MAIN relay) or G1-1 - Body ground | Always | 10 kΩ or higher |
| 5 (IG2-MAIN relay) or G2-1 - Body ground | Always | 10 kΩ or higher |
| OK | | GO TO ECM POWER SOURCE CIRCUIT |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
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