Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Voice Recognition Microphone Disconnected (B1579)

Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual / Audio & Visual & Telematics / Navigation / Multi Info Display / Navigation System / Voice Recognition Microphone Disconnected (B1579)

DESCRIPTION

The radio receiver assembly and telephone microphone assembly are connected to each other using the microphone connection detection signal lines.

This DTC is stored when a microphone connection detection signal line is disconnected.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

B1579

Voice Recognition Microphone Disconnected

Microphone signal is lost.
  • Telephone microphone assembly
  • DCM (telematics transceiver)
  • Radio receiver assembly
  • Harness or connector

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • Depending on the parts that are replaced during vehicle inspection or maintenance, performing initialization, registration or calibration may be needed. Refer to Precaution for Navigation System.

    Click here

  • Before replacing the DCM (telematics transceiver), refer to Registration.

    Click here

PROCEDURE

1.

INSPECT RADIO RECEIVER ASSEMBLY

(a) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

J151-22 (MIN-) - Body ground

Always

Below 1 Ω

*a

Component with harness connected

(Radio Receiver Assembly)
NG

REPLACE RADIO RECEIVER ASSEMBLY

OK

2.

CHECK HARNESS AND CONNECTOR (DCM (TELEMATICS TRANSCEIVER) - TELEPHONE MICROPHONE ASSEMBLY)

(a) Disconnect the J157 DCM (telematics transceiver) connector.

(b) Disconnect the U15 telephone microphone assembly connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

J157-7 (MCI-) - U15-4 (MCO-)

Always

Below 1 Ω

J157-7 (MCI-) or U15-4 (MCO-) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

3.

CHECK HARNESS AND CONNECTOR (RADIO RECEIVER ASSEMBLY - DCM (TELEMATICS TRANSCEIVER))

(a) Disconnect the J151 radio receiver assembly connector.

(b) Disconnect the J157 DCM (telematics transceiver) connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

J151-22 (MIN-) - J157-32(MCO-)

Always

Below 1 Ω

J151-22 (MIN-) or J157-32 (MCO-) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

4.

CHECK HARNESS AND CONNECTOR (RADIO RECEIVER ASSEMBLY - TELEPHONE MICROPHONE ASSEMBLY)

(a) Disconnect the J151 radio receiver assembly connector.

(b) Disconnect the U15 telephone microphone assembly connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

J151-25 (SNS2) - U15-3 (SNS2)

Always

Below 1 Ω

J151-25 (SNS2) or U15-3 (SNS2) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

5.

INSPECT DCM (TELEMATICS TRANSCEIVER)

(a) Reconnect the J157 DCM (telematics transceiver) connector.

(b) Reconnect the J151 radio receiver assembly connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

J157-7 (MCI-) - Body ground

Always

Below 1 Ω

*a

Component with harness connected

(DCM (Telematics Transceiver))

(d) Proceed to the next step based on the inspection result.

NG

REPLACE DCM (TELEMATICS TRANSCEIVER)

OK

6.

INSPECT TELEPHONE MICROPHONE ASSEMBLY

(a) Remove the telephone microphone assembly.

Click here

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

3 (SNS2) - 4 (MCO-)

Always

Below 1 Ω

*a

Component without harness connected

(Telephone Microphone Assembly)
OK

REPLACE RADIO RECEIVER ASSEMBLY

NG

REPLACE TELEPHONE MICROPHONE ASSEMBLY

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