DTC B1572-13: Microphone Circuit Open [08/2019 - ]: Procedure
WARNING: This page is about a different car, the 2022 Toyota Sequoia, 2021 Toyota Sequoia, and 2020 Toyota Sequoia. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK DTC
- Turn the engine switch off.
- Connect the Techstream to the DLC3.
- Turn the engine switch on (IG) and wait for 10 seconds or more.
- Turn the Techstream on.
- Clear the DTCs.
Refer to DTC CHECK / CLEAR [08/2019 - ]
- Check for DTCs and check that no DTCs are output.
OK
No DTCs are output.
Result
Proceed to OK NG
Result:
OK
USE SIMULATION METHOD TO CHECK. Refer to HOW TO PROCEED WITH TROUBLESHOOTING [08/2019 - ]
Result:
NG
See step 2
- CHECK HARNESS AND CONNECTOR (DCM [TELEMATICS TRANSCEIVER] - TELEPHONE MICROPHONE ASSEMBLY)
- Disconnect the H207 DCM (telematics transceiver) connector.
- Disconnect the U24 telephone microphone assembly connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition H207-5 (MCVD) - U24-1 (MACC) Always Below 1 Ω H207-6 (MCI+) - U24-2 (MIC+) Always Below 1 Ω H207-7 (MCI-) - U24-4 (MIC-) Always Below 1 Ω H207-23 (SGND) - Body ground Always 10 kΩ or higher H207-5 (MCVD) or U24-1 (MACC) - Body ground Always 10 kΩ or higher H207-6 (MCI+) or U24-2 (MIC+) - Body ground Always 10 kΩ or higher H207-7 (MCI-) or U24-4 (MIC-) - Body ground Always 10 kΩ or higher Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 3
- CHECK DCM (TELEMATICS TRANSCEIVER) (TELEPHONE MICROPHONE ASSEMBLY POWER SOURCE)
- Remove the telephone microphone assembly but do not disconnect the connectors.
*a Component with harness connected
(Telephone Microphone Assembly)Refer to REMOVAL [08/2019 - ]
- Measure the voltage and resistance according to the value(s) in the table below.
Standard Voltage
Tester Connection Switch Condition Specified Condition U24-1 (MACC) - Body ground Engine switch on (IG) 4 to 6 V Standard Resistance
Tester Connection Condition Specified Condition U24-4 (MIC-) - Body ground Always Below 1 Ω Result
Proceed to OK NG
Result:
OK
REPLACE TELEPHONE MICROPHONE ASSEMBLY. Refer to REMOVAL [08/2019 - ]
Result:
NG
See step 4
- Remove the telephone microphone assembly but do not disconnect the connectors.
- REPLACE DCM (TELEMATICS TRANSCEIVER)
- Replace the DCM (telematics transceiver) with a new one.
Refer to REMOVAL [08/2019 - ]
NOTE:- The engine switch must be off.
- Do not exchange the DCM (telematics transceiver) with one from another vehicle.
Result
Proceed to NEXT
Result:
NEXT
PERFORM DCM ACTIVATION. Refer to DCM ACTIVATION [08/2019 - ]
- Replace the DCM (telematics transceiver) with a new one.