Lexus NX: 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

Telephone microphone signal is lost.

  • Radio receiver assembly
  • Telephone microphone assembly
  • DCM (telematics transceiver) (w/ Manual [SOS] Switch)
  • Harness or connector

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • When replacing the radio receiver assembly, always replace it with a new one.

    If a radio receiver assembly which was installed to another vehicle is used, the following may occur:

    • A communication malfunction DTC may be stored.
    • The radio receiver assembly may not operate normally.
  • When replacing the DCM (telematics transceiver), make sure to replace it with a new one (w/ Manual [SOS] Switch).

HINT:

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

PROCEDURE

1.

CHECK VEHICLE TYPE

(a) Check the vehicle type.

Result

Proceed to

w/ Manual (SOS) Switch

A

w/o Manual (SOS) Switch

B

B

GO TO STEP 6

A

2.

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

(a) Disconnect the I152 radio receiver assembly connector.

(b) Disconnect the T21 telephone microphone assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

I152-25 (SNS2) - T21-3 (SNS2)

Always

Below 1 Ω

I152-25 (SNS2) - Body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3.

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

(a) Disconnect the I183 DCM (telematics transceiver) connector.

(b) Disconnect the T21 telephone microphone assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

I183-7 (MCI-) - T21-4 (MCO-)

Always

Below 1 Ω

I183-7 (MCI-) - Body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

4.

CHECK DCM (TELEMATICS TRANSCEIVER) (MCI-)

(a) Remove the DCM (telematics transceiver) with the connector(s) still connected.

Click here

*a

Component with harness connected

(DCM [Telematics Transceiver])

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

I183-7 (MCI-) - Body ground

Always

Below 1 Ω

NG

REPLACE DCM (TELEMATICS TRANSCEIVER)

OK

5.

INSPECT TELEPHONE MICROPHONE ASSEMBLY (SNS2, MCO-)

(a) Remove the telephone microphone assembly.

Click here

*a

Component without harness connected

(Telephone Microphone Assembly)

(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

OK

REPLACE RADIO RECEIVER ASSEMBLY

NG

REPLACE TELEPHONE MICROPHONE ASSEMBLY

6.

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

(a) Disconnect the I152 radio receiver assembly connector.

(b) Disconnect the T21 telephone microphone assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

I152-25 (SNS2) - T21-3 (SNS2)

Always

Below 1 Ω

I152-22 (MIN-) - T21-4 (MCO-)

Always

Below 1 Ω

I152-25 (SNS2) - Body ground

Always

10 kΩ or higher

I152-22 (MIN-) - Body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

7.

INSPECT TELEPHONE MICROPHONE ASSEMBLY (SNS2, MCO-)

(a) Remove the telephone microphone assembly.

Click here

*a

Component without harness connected

(Telephone Microphone Assembly)

(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

OK

REPLACE RADIO RECEIVER ASSEMBLY

NG

REPLACE TELEPHONE MICROPHONE ASSEMBLY

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