Lexus ES manuals

Lexus ES: UART Communication Between ANC and Audio Amplifier Missing Message (B1AA187)

Lexus ES (XZ10) Service Manual / Audio & Visual & Telematics / Audio / Video / Active Noise Control System (for Gasoline Model) / UART Communication Between ANC and Audio Amplifier Missing Message (B1AA187)

DESCRIPTION

This DTC is stored when an UART communication error occurs between the stereo component equalizer assembly and stereo component amplifier assembly.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

B1AA187

UART Communication Between ANC and Audio Amplifier Missing Message

Stereo component equalizer assembly detects a UART communication malfunction in stereo component amplifier assembly for 4 seconds or more continuously*

  • Harness or connector
  • Stereo component amplifier assembly
  • Stereo component equalizer assembly

HINT:

*: Malfunction monitoring is not performed under the following conditions, in order to prevent erroneous detection.

  • After engine switch is turned on (ACC) for 3 seconds or more.
  • After the battery voltage returns to normal for 3 seconds.
  • Before 3 seconds have elapsed after battery voltage has returned to normal.

WIRING DIAGRAM

PROCEDURE

1.

CLEAR DTC

(a) Clear the DTCs.

Body Electrical > Active Noise Control > Clear DTCs
NEXT

2.

CHECK FOR DTC

(a) Check for DTCs with all of the detection conditions met.

Body Electrical > Active Noise Control > Trouble Codes

OK:

No DTCs are output.

OK

USE SIMULATION METHOD TO CHECK

NG

3.

CHECK HARNESS AND CONNECTOR (STEREO COMPONENT EQUALIZER ASSEMBLY - STEREO COMPONENT AMPLIFIER ASSEMBLY)

(a) Disconnect the G15 stereo component equalizer assembly connector.

(b) Disconnect the G12 stereo component amplifier assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

G15-2 (ACK1) - G12-2 (ACK1)

Always

Below 1 Ω

G15-16 (ACK2) - G12-10 (ACK2)

Always

Below 1 Ω

G15-2 (ACK1) or G12-2 (ACK1) - Body ground

Always

10 kΩ or higher

G15-16 (ACK2) or G12-10 (ACK2) - Body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

4.

REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY

(a) Replace the stereo component amplifier assembly with a new or known good one.

Click here

NEXT

5.

CLEAR DTC

(a) Clear the DTCs.

Body Electrical > Active Noise Control > Clear DTCs
NEXT

6.

CHECK FOR DTC

(a) Check for DTCs with all of the detection conditions met.

Body Electrical > Active Noise Control > Trouble Codes

OK:

No DTCs are output.

OK

END (STEREO COMPONENT AMPLIFIER ASSEMBLY IS DEFECTIVE)

NG

REPLACE STEREO COMPONENT EQUALIZER ASSEMBLY

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