DTC B1572: Telephone Microphone Error [01/2018 - ]: Procedure

1. Turn the power switch off.
2. Connect the Techstream to the DLC3.
3. Turn the power 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 [01/2018 - ]

   Result

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

Result: 

B 

CHECK FOR INTERMITTENT PROBLEMS. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [06/2015 - 11/2018]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [11/2018 - ] 

Result: 

A 

See step  2

1. Remove the map light assembly but do not disconnect the connectors.

   Refer to REMOVAL [06/2015 - ]

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Component with harness connected (Map Light Assembly)

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

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   W8-22 (MACC) - Body ground	Power switch on (ACC)	4 to 6 V

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   W8-20 (MCO-) - Body ground	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  5

Result: 

OK 

See step  3

1. Disconnect the G55 DCM (Telematics Transceiver) connector.
2. Disconnect the W8 map light assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   G55-34 (MCI+) - W8-21 (MCO+)	Always	Below 1 Ω
   G55-34 (MCI+) - Body ground	Always	10 kΩ or higher
   W8-21 (MCO+) - Body ground	Always	10 kΩ or higher
   G55-35 (MCI-) - W8-20 (MCO-)	Always	Below 1 Ω
   G55-35 (MCI-) - Body ground	Always	10 kΩ or higher
   W8-20 (MCO-) - Body ground	Always	10 kΩ or higher
   G55-32 (SGND) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  4

1. Replace the telephone microphone assembly with a normal one and check if the same problem occurs again.

   Refer to REMOVAL [06/2015 - ]

   OK

   The system returns to normal.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

END (TELEPHONE MICROPHONE ASSEMBLY IS DEFECTIVE) 

Result: 

NG 

REPLACE MAP LIGHT ASSEMBLY. Refer to  REMOVAL [06/2015 - ] 

1. Remove the DCM (Telematics Transceiver) but do not disconnect the connectors.

   Refer to REMOVAL [01/2018 - 11/2018] , or refer to REMOVAL [11/2018 - ]

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

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

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   G55-33 (MCVD) - Body ground	Power switch on (ACC)	4 to 6 V

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   G55-35 (MCI-) - Body ground	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

NG 

See step  6

1. Replace the DCM (Telematics Transceiver).

   Refer to REMOVAL [01/2018 - 11/2018] , or refer to REMOVAL [11/2018 - ]

   NOTE:

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

   Result

   Proceed to
   NEXT

Result: 

NEXT 

PERFORM DCM ACTIVATION. Refer to  DCM ACTIVATION [01/2018 - ]