Operation CHARM: Car repair manuals for everyone.
Home >> Lexus >> 2011 >> IS 350 AWD V6-3.5L (2GR-FSE) >> Repair and Diagnosis >> Lighting and Horns >> Testing and Inspection >> Component Tests and General Diagnostics >> Lighting System >> Taillight Circuit

Taillight Circuit





LIGHTING: LIGHTING SYSTEM: Taillight Circuit
- Taillight Circuit

DESCRIPTION

Front lights (HID Type, w/ Daytime running lights):

The front controller controls the operation of the FR TAIL relay. The FR TAIL relay turns on the front side marker lights and an IC relay in the front controller operates the parking lights.

Front lights (HID Type, w/o Daytime running lights or Except HID Type):

The front controller controls the operation of the FR TAIL relay. The FR TAIL relay turns on the front side marker lights and parking lights.

The front controller receives front side marker and parking light ON request signals from the combination switch ECU through BEAN communication and activates the FR TAIL relay and IC relay.

The FR TAIL relay is built into the front controller, so unlike conventional relays, it cannot be removed for inspection.

Rear lights:

The main body ECU RH controls the operation of the TAIL relay. The TAIL relay turns on the taillights, license plate lights, and side marker lights.

The main body ECU RH receives taillight, license plate light, and side marker light ON request signals from the combination switch ECU through BEAN communication and activates the TAIL relay.

The TAIL relay is built into the cowl side junction block LH, so unlike conventional relays, it cannot be removed for inspection.

WIRING DIAGRAM

1. Front Lights (HID Type, w/ Daytime Running Lights)





2. Front Lights (HID Type, w/o Daytime Running Lights)





3. Front Lights (Except HID Type)





4. Rear Lights





INSPECTION PROCEDURE

NOTICE:
Before proceeding to the following flowchart, check that the fuses are not blown and that the bulbs are not burned out.

PROCEDURE

1. CHECK TAILLIGHT (OPERATION)

(a) Turn the engine switch on (IG).

(b) When the taillight switch is operated, check that the following lights illuminate.

HINT
* HID Type, w/ Daytime running lights
The front lights (front side marker lights and parking lights) are operated by the front controller via either a mechanical relay or built-in IC relay. If one of the front lights does not illuminate, there may be a problem in the circuit between the relay and light, or in the circuit between the light and ground.
* HID Type, w/o Daytime running lights or Except HID Type
The front lights (front side marker lights and parking lights) are operated by the front controller via a mechanical relay. If one of the front lights does not illuminate, there may be a problem in the circuit between the relay and light, or in the circuit between the light and ground.
* The rear lights (taillights, license plate lights, and side marker lights) share the same drive circuit. Therefore, if one of the rear lights does not come on, there may be a problem in the circuit between the TAIL relay and the bulb or LED, or the circuit between the bulb or LED and body ground. Inspect those circuits to identify the problem.

Result:





C -- PERFORM ACTIVE TEST USING TECHSTREAM

B -- PERFORM ACTIVE TEST USING TECHSTREAM

A -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

2. PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Body No. 5 / Active Test.

(e) Check the operation.

Body No. 5 (Front Controller):





OK:

Front side marker lights and parking lights illuminate.

Result:





C -- CHECK HARNESS AND CONNECTOR (HEADLIGHT - BODY GROUND)

B -- CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - BODY GROUND)

A -- REPLACE ENGINE ROOM NO. 2 R/B (FRONT CONTROLLER)

3. CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - BODY GROUND)

HINT
Perform the following inspection on either the LH or RH side.

(a) Disconnect the B2 or B12 headlight assembly connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

RH side





LH side





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

4. CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - ENGINE ROOM NO. 2 R/B)

HINT
Perform the following inspection on either the LH or RH side.

(a) Disconnect the B2 or B12 headlight assembly connector.

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

RH Side





LH Side





Result:





C -- CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - ENGINE ROOM NO. 2 R/B)

B -- CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - ENGINE ROOM NO. 2 R/B)

A -- REPLACE HEADLIGHT ASSEMBLY

5. CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - ENGINE ROOM NO. 2 R/B)

HINT
Perform the following inspection on either the LH or RH side.

(a) Disconnect the B2 and B12 headlight assembly connector.

(b) Disconnect the 2G engine room No.2 R/B connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

RH Side





LH Side





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ENGINE ROOM NO. 2 R/B (FRONT CONTROLLER)

6. CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - ENGINE ROOM NO. 2 R/B)

HINT
Perform the following inspection on either the LH or RH side.

(a) Disconnect the B2 or B12 headlight assembly connector.

(b) Disconnect the 2G engine room No.2 R/B connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

RH Side





LH Side





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ENGINE ROOM NO. 2 R/B (FRONT CONTROLLER)

7. CHECK HARNESS AND CONNECTOR (HEADLIGHT - BODY GROUND)

HINT
Perform the following inspection on either the LH or RH side.

(a) Disconnect the B2 or B12 headlight connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard resistance:

RH side
LH side










NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

8. CHECK HARNESS AND CONNECTOR (HEADLIGHT - BODY GROUND)

HINT
Perform the following inspection on either the LH or RH side.

(a) Disconnect the B2 or B12 headlight connector.

(b) Measure the voltage according to the value(s) in the table below.

Standard voltage:

RH side
LH side










NG -- CHECK HARNESS AND CONNECTOR (HEADLIGHT - ENGINE ROOM NO. 2 R/B)

OK -- REPLACE HEADLIGHT ASSEMBLY

9. CHECK HARNESS AND CONNECTOR (HEADLIGHT - ENGINE ROOM NO. 2 R/B)

HINT
Perform the following inspection on either the LH or RH side.

(a) Disconnect the B2 or B12 headlight connector.

(b) Disconnect the 2G engine room No. 2 R/B connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard resistance:

RH side
LH side










NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ENGINE ROOM NO. 2 R/B (FRONT CONTROLLER)

10. PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Body / Active Test.

(e) Check the operation.

Body (Main Body ECU RH):





OK:

Taillights, license plate lights and side marker lights illuminate.

Result:





HINT
If the outer taillights illuminate normally, but the side marker lights do not illuminate, or vice versa, there is an open circuit in the rear combination light.

E -- CHECK HARNESS AND CONNECTOR (MAIN BODY ECU RH - BODY GROUND)

D -- REPLACE MAIN BODY ECU RH (COWL SIDE J/B RH)

C -- CHECK HARNESS AND CONNECTOR (LICENSE PLATE LIGHT LH - BODY GROUND)

B -- CHECK HARNESS AND CONNECTOR (OUTER TAILLIGHT - BODY GROUND)
A -- Continue to next step.

11. CHECK HARNESS AND CONNECTOR (INNER TAILLIGHT - BODY GROUND)

HINT
Perform the following inspection on either the LH or RH side.

(a) Disconnect the Q46 or Q40 inner taillight connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard resistance:

RH side
LH side










NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

12. CHECK HARNESS AND CONNECTOR (INNER TAILLIGHT - MAIN BODY ECU LH)

HINT
Perform the following inspection on either the LH or RH side.

(a) Disconnect the Q46 or Q40 inner taillight connector.

(b) Measure the voltage according to the value(s) in the table below.

Standard voltage:

RH side
LH side










NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE INNER COMBINATION LIGHT

13. CHECK HARNESS AND CONNECTOR (OUTER TAILLIGHT - BODY GROUND)

HINT
Perform the following inspection on either the LH or RH side.

(a) Disconnect the Q51 or Q50 outer taillight connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard resistance:

RH side
LH side










NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

14. CHECK HARNESS AND CONNECTOR (OUTER TAILLIGHT - MAIN BODY ECU LH)

HINT
Perform the following inspection on either the LH or RH side.

(a) Disconnect the Q51 or Q50 outer taillight connector.

(b) Measure the voltage according to the value(s) in the table below.

Standard voltage:

RH side
LH side










NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE OUTER COMBINATION LIGHT

15. CHECK HARNESS AND CONNECTOR (LICENSE PLATE LIGHT LH - BODY GROUND)

HINT
Perform the following inspection on the LH side.

(a) Disconnect the Q47 license plate light LH connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

16. CHECK HARNESS AND CONNECTOR (LICENSE PLATE LIGHT RH - MAIN BODY ECU LH)

HINT
Perform the following inspection on the RH side.

(a) Disconnect the Q44 license plate light RH connector.

(b) Measure the voltage according to the value(s) in the table below.

Standard voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

17. CHECK HARNESS AND CONNECTOR (LICENSE PLATE LIGHT LH - LICENSE PLATE LIGHT LH)

HINT
Perform the following inspection on the LH side.

(a) Connect the Q44 license plate light RH connector.

(b) Disconnect the Q47 license plate light LH connector.

(c) Measure the voltage according to the value(s) in the table below.

Standard voltage:





NG -- CHECK HARNESS AND CONNECTOR (LICENSE PLATE LIGHT LH - LICENSE PLATE LIGHT RH)

OK -- REPLACE LICENSE PLATE LIGHT (LH SIDE)

18. CHECK HARNESS AND CONNECTOR (LICENSE PLATE LIGHT LH - LICENSE PLATE LIGHT RH)

(a) Disconnect the Q44 license plate light RH connector.

(b) Disconnect the Q47 license plate light LH connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE LICENSE PLATE LIGHT (RH SIDE)

19. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU RH - BODY GROUND)

(a) Disconnect the RD main body ECU RH connector.

(b) Measure the voltage according to the value(s) in the table below.

Standard voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

20. INSPECT MAIN BODY ECU RH (COWL SIDE J/B RH)

(a) Connect the RD main body ECU RH connector.





(b) Measure the voltage according to the value(s) in the table below.

Standard voltage:





NG -- REPLACE MAIN BODY ECU RH (COWL SIDE J/B RH)
OK -- Continue to next step.

21. INSPECT MAIN BODY ECU LH (COWL SIDE J/B LH)

(a) Measure the voltage according to the value(s) in the table below.





Standard voltage:





NG -- REPLACE MAIN BODY ECU LH (COWL SIDE J/B LH)

OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (MAIN BODY ECU LH - EACH REAR LIGHT)
pro multis · About Operation CHARM