Microphone Circuit between Microphone and Radio Receiver (TO 12/2010): Procedure

WARNING: This page is about a different car, the 2011 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT RADIO RECEIVER ASSEMBLY

Disconnect the radio receiver assembly connector.

Fig 1: Identifying Radio Receiver Assembly Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard Voltage

Tester Connection	Condition	Specified Condition
E40-3 (MACC) - Body ground	Ignition switch ON	4 to 6 V

TEXT IN ILLUSTRATION

*a	Component without harness connected (Radio Receiver Assembly)

NG → See step 6

OK: Go to next step

CHECK HARNESS AND CONNECTOR (INNER REAR VIEW MIRROR ASSEMBLY - RADIO RECEIVER ASSEMBLY)

Disconnect the inner rear view mirror assembly and radio receiver assembly connectors.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
N9-10 (SGND) - E40-1 (SNS2)	Always	Below 1 Ω
N9-11 (MIC+) - E40-2 (MIC+)	Always	Below 1 Ω
N9-12 (MIC-) - E40-5 (MIC-)	Always	Below 1 Ω
N9-9 (MACC) - E40-3 (MACC)	Always	Below 1 Ω
N9-10 (SGND) - Body ground	Always	10 kΩ or higher
N9-11 (MIC+) - Body ground	Always	10 kΩ or higher
N9-12 (MIC-) - Body ground	Always	10 kΩ or higher
N9-9 (MACC) - Body ground	Always	10 kΩ or higher
E40-6 (SGND) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

INSPECT INNER REAR VIEW MIRROR ASSEMBLY

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

Fig 2: Identifying Inner Rear View Mirror Assembly Connector Terminals

Standard Resistance

Tester Connection	Condition	Specified Condition
N9-10 (SGND) - N9-12 (MIC-)	Always	Below 1 Ω

TEXT IN ILLUSTRATION

*a	Component without harness connected (Inner Rear View Mirror Assembly)

NG → See step 7

OK: Go to next step

REPLACE INNER REAR VIEW MIRROR ASSEMBLY
1. Check that the malfunction disappears when a known good inner rear view mirror assembly is installed. Refer to REMOVAL .
  OK
  
  Malfunction disappears.
NG → See step 5

OK → END (INNER REAR VIEW MIRROR ASSEMBLY WAS DEFECTIVE)
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to PROBLEM SYMPTOMS TABLE
REPLACE RADIO RECEIVER ASSEMBLY. Refer to REMOVAL
REPLACE INNER REAR VIEW MIRROR ASSEMBLY. Refer to REMOVAL