Communication Signal Circuit

COMMUNICATION SIGNAL CIRCUIT

SATELLITE RADIO TUNER : Description

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


SATELLITE RADIO TUNER : Diagnosis Procedure

Regarding Wiring Diagram information, 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 CONSULT or oscilloscope.





Are voltage readings as specified?
YES- GO TO 5
NO- Replace audio unit. Premium Audio (Crew Cab).

5. CHECK TXD SIGNAL






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





Are the voltage readings as specified?
YES- GO TO 6
NO- Replace satellite radio tuner. Premium Audio (Crew Cab)

6. CHECK RXD SIGNAL






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





Are the voltage readings as specified?
YES- Replace satellite radio tuner. Premium Audio (Crew Cab).
NO- Replace audio unit. Premium Audio (Crew Cab).