Communication Signal Circuit Check [Satellite Radio Tuner]

Communication Signal Circuit Check [Satellite Radio Tuner]

Description

Communication signals are exchanged between the audio unit and satellite radio tuner using the communication circuits.

Diagnosis Procedure

Regarding Wiring Diagram information, refer to [Premium Audio System: Wiring Diagram [Crew Cab] Premium Audio System [Crew Cab] ].

1. CHECK HARNESS - REQ1

1 Turn ignition switch OFF.





2 Disconnect satellite radio tuner (factory installed) connector M41 and audio unit connector M48.
3 Check continuity between satellite radio tuner (factory installed) harness connector M41 (A) terminal 28 and audio unit harness connector M48 (B) terminal 48.






4 Check continuity between satellite radio tuner (factory installed) harness connector M41 (A) terminal 28 and ground.






Are continuity results as specified?
YES
GO TO 2
NO
Repair or replace harness or connector.

2. CHECK HARNESS - TXD

1 Check continuity between satellite radio tuner (factory installed) harness connector M41 (A) terminal 29 and audio unit harness connector M48 (B) terminal 49.











2 Check continuity between satellite radio tuner (factory installed) harness connector M41 (A) terminal 29 and ground.






Are continuity results as specified?
YES
GO TO 3
NO
Repair or replace harness or connector.

3. CHECK HARNESS - RXD

1 Check continuity between satellite radio tuner (factory installed) harness connector M41 (A) terminal 30 and audio unit harness connector M48 (B) terminal 50.











2 Check continuity between satellite radio tuner (factory installed) harness connector M41 (A) terminal 30 and ground.






Are continuity results as specified?
YES
GO TO 4
NO
Repair or replace harness or connector.

4. CHECK REQ1 SIGNAL

1 Connect satellite radio tuner (factory installed) connector and audio unit connector.
2 Turn ignition switch to ACC
3 Check signal between satellite radio tuner (factory installed) harness connector M41 terminal 28 and ground with SDT or oscilloscope.











Are voltage readings as specified?
YES
GO TO 5
NO
Replace audio unit. Refer to [Audio Unit: Removal and Installation] Audio Unit.

5. CHECK TXD SIGNAL

Check signal between satellite radio tuner (factory installed) harness connector M41 terminal 29 and ground with SDT or oscilloscope.











Are the voltage readings as specified?
YES
GO TO 6
NO
Replace satellite radio tuner. Refer to [Satellite Radio Tuner: Removal and Installation] Premium Audio (Crew Cab).

6. CHECK RXD SIGNAL

Check signal between satellite radio tuner (factory installed) harness connector M41 terminal 30 and ground with SDT or oscilloscope.











Are the voltage readings as specified?
YES
Replace satellite radio tuner. Refer to [Satellite Radio Tuner: Removal and Installation] Premium Audio (Crew Cab).
NO
Replace audio unit. Refer to [Audio Unit: Removal and Installation] Audio Unit.