Illumination Circuit

NAVIGATION: NAVIGATION SYSTEM (for CrewMax): Illumination Circuit

Illumination Circuit

DESCRIPTION

Power is supplied to the illumination circuit for the navigation receiver and steering pad switch when the light control switch is in the TAIL or HEAD position.

WIRING DIAGRAM





INSPECTION PROCEDURE
CAUTION: The vehicle is equipped with an SRS (Supplemental Restraint System) which includes components such as airbags. Before servicing (including removal or installation of parts), be sure to read the PRECAUTION in the Supplemental Restraint System. (Service Precautions).

PROCEDURE

1. CHECK ILLUMINATION
(a) Check if the illumination for the navigation receiver, steering pad switch, glove box light or other parts (seat heater switch, room light switch, etc.) come on when the light control switch is turned to the HEAD or TAIL position.

Result





D -- CHECK HARNESS AND CONNECTOR (NAVIGATION RECEIVER - COMBINATION METER)
C -- GO TO LIGHTING SYSTEM
B -- CHECK HARNESS AND CONNECTOR (NAVIGATION RECEIVER - BATTERY)
A -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (SPIRAL CABLE - NAVIGATION RECEIVER AND BATTERY)





(a) Disconnect the J45 cable connector.
(b) Disconnect the K21 receiver connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:





(d) 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.
3. INSPECT STEERING PAD SWITCH ASSEMBLY





(a) Disconnect the z3 switch connector.
(b) Connect the positive (+) lead to terminal 5 (IL+2) and the negative (-) lead to terminal 8 (EAU) of the steering pad switch connector.
(c) Check if the illumination for the steering pad switch comes on.
OK:
Illumination for the steering pad switch comes on.
NG -- REPLACE STEERING PAD SWITCH ASSEMBLY
OK -- Continue to next step.
4. INSPECT SPIRAL CABLE





(a) Disconnect the z3 and J45 cable connectors.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:





CAUTION: The spiral cable is an important part of the SRS airbag system. Incorrect removal or installation of the spiral cable may prevent the airbag from deploying. Be sure to read the PRECAUTION for the supplemental restraint system (Service Precautions).

NG -- REPLACE SPIRAL CABLE SUB-ASSEMBLY
OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
5. CHECK HARNESS AND CONNECTOR (NAVIGATION RECEIVER - BATTERY)





(a) Disconnect the K18 receiver connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
6. CHECK HARNESS AND CONNECTOR (NAVIGATION RECEIVER - COMBINATION METER)





(a) Disconnect the K18 display connector.
(b) Disconnect the J28 meter connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE