DTC B1572: Telephone Microphone Error [08/2013 - 12/2013]: Procedure

1. Turn the engine switch off.
2. Connect the Techstream to the DLC3.
3. Turn the engine switch on (IG) and wait for 10 seconds.
4. Turn the Techstream on.
5. Perform "Health Check" and check for current DTCs. Refer to HEALTH CHECK [08/2013 - ] .

   Result

   Result	Proceed to
   DTC B1572 is output	A
   DTC B1572 is not output	B

B → See step   6 

A: Go to next step 

1. Remove the roof console box assembly but do not disconnect the connectors. Refer to REMOVAL [08/2013 - ] .

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. Measure the voltage and resistance according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   S12-14 (MACC) - Body ground	Engine switch on (ACC)	4 to 6 V

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   S12-12 (MCO-) - Body ground	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *a	Component with harness connected (Roof Console Box Assembly)

NG → See step   4 

OK: Go to next step 

1. Disconnect the I135 DCM (Telematics Transceiver) connector.
2. Disconnect the S12 roof console box assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   I135-34 (MCI+) - S12-13 (MCO+)	Always	Below 1 Ω
   I135-35 (MCI-) - S12-12 (MCO-)	Always	Below 1 Ω
   I135-34 (MCI+) - Body ground	Always	10 kΩ or higher
   I135-35 (MCI-) - Body ground	Always	10 kΩ or higher
   I135-32 (SGND) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   8 

1. Remove the DCM (Telematics Transceiver) but do not disconnect the connectors. Refer to REMOVAL [08/2013 - ] .

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. Measure the voltage and resistance according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   I135-33 (MCVD) - Body ground	Engine switch on (ACC)	4 to 6 V

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   I135-35 (MCI-) - Body ground	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *a	Component with harness connected (DCM (Telematics Transceiver)

NG → See step   5 

OK → REPAIR OR REPLACE HARNESS OR CONNECTOR 

1. Replace the DCM (Telematics Transceiver). Refer to REMOVAL [08/2013 - ] .
   NOTE:

   • The engine switch must be off.
   • Do not swap the DCM (Telematics Transceiver) with one from another vehicle.

NEXT → See step   7