Lexus NX: Taillight Relay Circuit
DESCRIPTION
Illumination of the taillights and license plate light is controlled by the main body ECU (multiplex network body ECU).
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
- Inspect the fuses for circuits related to this system before performing the following procedure.
- Recognition code registration is necessary when replacing the main body ECU (multiplex network body ECU).
- If the main body ECU (multiplex network body ECU) is replaced, refer to Registration.
PROCEDURE
| 1. | PERFORM ACTIVE TEST USING TECHSTREAM (TAILLIGHT RELAY) |
(a) Using the Techstream, perform the Active Test.
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| Tester Display | Measurement Item | Control Range | Diagnostic Note |
|---|---|---|---|
| Taillight Relay | Taillight relay | ON or OFF | - |
| Tester Display |
|---|
| Taillight Relay |
| Result | Proceed to |
|---|---|
| Taillights, license lights, clearance light and side marker lights come on | A |
| Taillights, license lights, clearance light and side marker lights do not come on | B |
| A | .gif) | PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
|
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| 2. | CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - BATTERY) |
(a) Disconnect the instrument panel junction block assembly connector.
| (b) Measure the voltage according to the value(s) in the table below. Standard Voltage:
|
|
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
| 3. | INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY |
(a) Remove the instrument panel junction block assembly.
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(b) Remove the instrument panel junction block assembly.
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(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| 4A-37 - Battery negative (-) terminal | Battery voltage applied between terminals 4F-1 and A-14 (TRLY) | 11 to 14 V |
| Battery voltage not applied between terminals 4F-1 and A-14 (TRLY) | Below 1 V | |
| 4A-38 - Battery negative (-) terminal | Battery voltage applied between terminals 4F-1 and A-14 (TRLY) | 11 to 14 V |
| Battery voltage not applied between terminals 4F-1 and A-14 (TRLY) | Below 1 V | |
| 4B-24 - Battery negative (-) terminal | Battery voltage applied between terminals 4F-1 and A-14 (TRLY) | 11 to 14 V |
| Battery voltage not applied between terminals 4F-1 and A-14 (TRLY) | Below 1 V | |
| 4B-25 - Battery negative (-) terminal | Battery voltage applied between terminals 4F-1 and A-14 (TRLY) | 11 to 14 V |
| Battery voltage not applied between terminals 4F-1 and A-14 (TRLY) | Below 1 V | |
| 4B-26 - Battery negative (-) terminal | Battery voltage applied between terminals 4F-1 and A-14 (TRLY) | 11 to 14 V |
| Battery voltage not applied between terminals 4F-1 and A-14 (TRLY) | Below 1 V |
| OK | | REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) |
| NG | | REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY |
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DESCRIPTION The main body ECU (multiplex network body ECU) controls the high beam headlights. WIRING DIAGRAM CAUTION / NOTICE / HINT NOTICE:
Inspect the fuses for circuits related to this system b
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MIL Circuit
DESCRIPTION The Malfunction Indicator Lamp (MIL) is used to indicate vehicle malfunctions detected by the ECM. The MIL operation can be checked visually. When the power switch is turned on (IG), the MIL should be illuminated and should then turn off after the power switch on (READY). If the MIL rema
Repair
REPAIR CAUTION / NOTICE / HINT HINT:
Use the same procedure for the RH and LH sides.
The procedure listed below is for the LH side.
If the installation area of the headlight assembly is damaged, use the supply retainer for low-cost repair.
Make sure that the headlight assembly is not damage
