Inspection Procedure

WARNING: This page is about a different car, the 2007 Toyota Tacoma. However, it is still accessible from the selected car via links, so may be relevant.

SYSTEM CHECK
1. Turn the light control switch to the TAIL or HEAD position.
  Check whether other displays and indicators such as the A/C switch indicator come on.
  
  OK: Other displays and indicators come on.
NG: GO TO LIGHTING SYSTEM

OK: Go to Next Step

CHECK SYMPTOMS

Check the symptom.

Check whether the illumination for the radio receiver assembly or steering pad switch comes on.

SYMPTOM REFERENCE

Symptom	Proceed To
Illumination for radio receiver assembly does not come on.	A
Illumination for steering pad switch does not come on.	B

B: Go to step 5

A: Go to next step

CHECK RADIO RECEIVER ASSEMBLY

Disconnect the R1 radio receiver assembly connector.
Turn the light control switch to the TAIL or HEAD position.

Measure the voltage.

Standard: Built-in AMP

TESTER CONNECTION AND SPECIFIED CONDITION

Tester Connection	Light control switch TAIL	Specified Condition
ILL+ (R1-10) - Body ground	Light control switch TAIL	10 to 14 V

Standard: Separate AMP

TESTER CONNECTION AND SPECIFIED CONDITION

Tester Connection	Light control switch TAIL	Specified Condition
ILL+ (R1-2) - Body ground	Light control switch TAIL	10 to 14 V

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

Fig 1: Identifying R1 Radio Receiver Assembly Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: Go to next step

CHECK HARNESS AND CONNECTOR (RADIO RECEIVER ASSEMBLY - LIGHT CONTROL RHEOSTAT)

Disconnect the R2 or R1 radio receiver assembly connector and R4 light control rheostat connector.

Measure the resistance.

Standard: Built-in AMP

TESTER CONNECTION AND SPECIFIED CONDITION

Tester Connection	Specified Condition
ILL- (R2-5) - (R4-3)	Below 1
ILL- (R2-5) - Body ground	10 k or higher

Standard: Separate AMP

TESTER CONNECTION AND SPECIFIED CONDITION

Tester Connection	Specified Condition
ILL- (R1-12) - (R4-3)	Below 1
ILL- (R1-2) - Body ground	10 k or higher

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

Fig 2: Identifying R4 Light Control Rheostat Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

INSPECT STEERING PAD SWITCH LH

Fig 3: Inspecting Steering Pad Switch LH
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NOTE: The vehicle is equipped with the SRS (Supplemental Restraint System) such as airbags. Before servicing (including removal or installation of parts), be sure to read the PRECAUTION notice for the Supplemental Restraint System article.
1. Disconnect the steering pad switch assembly connector.
2. Connect the positive (+) lead to terminal ILL+ and the negative (-) lead to terminal EAU of the steering pad switch assembly connector.
3. Check the illumination for the steering pad switch assembly.
  OK: Illumination for the steering pad switch assembly comes on.
NG: REPLACE STEERING PAD SWITCH LH

OK: Go to next step

CHECK HARNESS AND CONNECTOR (SPIRAL CABLE SUB-ASSEMBLY - RADIO RECEIVER ASSEMBLY)

Disconnect the R3 radio receiver assembly connector.
Disconnect the S8 spiral cable sub-assembly connector.

Measure the resistance.

Standard

TESTER CONNECTION AND SPECIFIED CONDITION

Tester Connection	Specified Condition
SWG (R3-6) - EAU (S8-4)	Below 1

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

Fig 4: Identifying S8 Spiral Cable Sub-Assembly Connector Terminals

OK: Go to next step

INSPECT SPIRAL CABLE SUB-ASSEMBLY

Disconnect the spiral cable sub-assembly connector.

Check the resistance.

Standard

TESTER CONNECTION AND SPECIFIED CONDITION

Tester Connection	Specified Condition
EAU - EAU	Below 1
ILL+ - ILL+2	Below 1

NG: REPLACE SPIRAL CABLE SUB-ASSEMBLY

Fig 5: Disconnecting Spiral Cable Sub-Assembly Connector

OK: REPAIR OR REPLACE HARNESS AND CONNECTOR (SPIRAL CABLE SUB-ASSEMBLY - DRIVER SIDE J/B)