DTC B1572-13: Microphone Circuit Open [09/2022 - ]: Procedure
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2024 Lexus ES 300h, 2023 Lexus ES 300h, 2022 Lexus ES 300h, 2021 Lexus ES 300h, and 2020 Lexus ES 300h. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK DTC
- Turn the power switch off.
- Connect the Techstream to the DLC3.
- Turn the power switch on (IG) and wait for 10 seconds or more.
- Turn the Techstream on.
- Clear the DTCs.
Body Electrical > Telematics > Clear DTCs
- Check for DTCs and check that no DTCs are output.
Body Electrical > Telematics > Trouble Codes
OK
No DTCs are output.
Result
Proceed to OK NG
Result:
OK
USE SIMULATION METHOD TO CHECK. Refer to HOW TO PROCEED WITH TROUBLESHOOTING [06/2018 - ]
Result:
NG
See step 2
- CHECK HARNESS AND CONNECTOR (DCM (TELEMATICS TRANSCEIVER) - TELEPHONE MICROPHONE ASSEMBLY LH)
- Disconnect the G128 DCM (telematics transceiver) connector.
- Disconnect the P24 telephone microphone assembly LH connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition G128-5 (MCVD) - P24-1 (MAC1) Always Below 1 Ω G128-6 (MCI+) - P24-2 (MO1+) Always Below 1 Ω G128-7 (MCI-) - P24-4 (MO1-) Always Below 1 Ω G128-23 (SGND) - Body ground Always 10 kΩ or higher G128-5 (MCVD) or P24-1 (MAC1) - Body ground Always 10 kΩ or higher G128-6 (MCI+) or P24-2 (MO1+) - Body ground Always 10 kΩ or higher G128-7 (MCI-) or P24-4 (MO1-) - 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 LH POWER SOURCE)
- Remove the telephone microphone assembly LH but do not disconnect the connectors.
Refer to REMOVAL [09/2022 - ]
- Measure the voltage and resistance according to the value(s) in the table below.
*a Component with harness connected
(Telephone Microphone Assembly LH)Standard Voltage
Tester Connection Switch Condition Specified Condition P24-1 (MAC1) - Body ground Power switch on (IG) 7.5 to 8.5 V Standard Resistance
Tester Connection Condition Specified Condition P24-4 (MO1-) - Body ground Always Below 1 Ω Result
Proceed to OK NG
Result:
OK
REPLACE TELEPHONE MICROPHONE ASSEMBLY LH. Refer to REMOVAL [09/2022 - ]
Result:
NG
See step 4
- Remove the telephone microphone assembly LH but do not disconnect the connectors.
- REPLACE DCM (TELEMATICS TRANSCEIVER)
- Replace the DCM (telematics transceiver) with a new one.
Refer to REMOVAL [09/2022 - ]
NOTE:- The power 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 [10/2019 - ]
- Replace the DCM (telematics transceiver) with a new one.