Diagnosis Procedure

Regarding Wiring Diagram information, refer to "WIRING DIAGRAM ".

1. HARNESS CHECK
   1. Disconnect audio amplifier connector B159 and suspect tweeter connector.
   2. Check continuity between audio amplifier harness connector B159 (A) and suspect tweeter harness connector (B).
      CONTINUITY REFERENCE CHART
      
      

      A		B		Continuity
      Connector	Terminal	Connector	Terminal
      B159	14	M109	1	Yes
      	30		2
      	13	M111	1
      	29		2

   3. Check continuity between audio amplifier harness connector B159 (A) and ground.
      CONTINUITY REFERENCE CHART
      
      

      A		-	Continuity
      Connector	Terminal
      B159	14	Ground	No
      	30
      	13
      	29

      Fig 1: Checking Continuity Between Audio Amplifier Harness Connector B159 And Ground

      

      Are continuity test results as specified? 

      YES: GO TO 2

      NO:

      • Check connector housings for disconnected or loose terminals.
      • Repair harness or connector.
2. FRONT TWEETER SIGNAL CHECK
   1. Connect audio amplifier connector B159 and suspect tweeter connector.
   2. Turn ignition switch to ACC.
   3. Push audio unit "POWER" switch.
   4. Check the signal between audio amplifier harness connector B159 terminals with CONSULT-III or oscilloscope.
      SIGNAL REFERENCE CHART
      
      

      Connector	Terminal		Condition	Reference signal
      	(+)	(-)
      B159	14	30	Receive audio signal
      	13	29

      Fig 2: Checking Signal Between Audio Amplifier Harness Connector B159 Terminals With CONSULT-III Or Oscilloscope

      

      Is audio signal voltage as specified? 

      YES: Replace suspect tweeter. Refer to "REMOVAL AND INSTALLATION ".

      NO: GO TO 3

3. AUDIO UNIT AND AUDIO AMPLIFIER HARNESS CHECK
   1. Disconnect audio unit connector M46 and audio amplifier connector B159.
   2. Check continuity between audio unit harness connector M46 (A) and audio amplifier harness connector B159 (B).
      CONTINUITY REFERENCE CHART
      
      

      A		B		Continuity
      Connector	Terminal	Connector	Terminal
      M46	1	B159	6	Yes
      	2		22
      	3		5
      	4		21

   3. Check continuity between audio unit harness connector M46 (A) and ground.
      CONTINUITY REFERENCE CHART
      
      

      A		-	Continuity
      Connector	Terminal
      M46	1	Ground	No
      	2
      	3
      	4

      Fig 3: Checking Continuity Between Audio Unit Harness Connector M46 And Ground

      

      Are continuity test results as specified? 

      YES: GO TO 4

      NO:

      • Check connector housings for disconnected or loose terminals.
      • Repair harness or connector.
4. AUDIO AMPLIFIER SIGNAL CHECK
   1. Connect audio unit connector and audio amplifier connector.
   2. Turn ignition switch ACC.
   3. Push audio unit "POWER" switch.
   4. Check the signal between audio unit harness connector M46 terminals with CONSULT-III or oscilloscope.
      SIGNAL REFERENCE CHART
      
      

      Connector	Terminals		Condition	Reference signal
      	(+)	(-)
      M46	2	1	Receive audio signal
      	4	3

      Fig 4: Checking Signal Between Audio Unit Harness Connector M46 Terminals With CONSULT-III Or Oscilloscope

      

      Are the audio signal voltage readings as specified? 

      YES: Replace audio amplifier. Refer to "REMOVAL AND INSTALLATION ".

      NO: Replace audio unit. Refer to "REMOVAL AND INSTALLATION ".