AUDIO / VIDEO: AUDIO AND VISUAL SYSTEM (for Gasoline Model with Dual Knob Type): B15DB; Telematics Transceiver Disconnected; 2020 MY Corolla Corolla Hatchback GR Corolla [01/2019

Last Modified: 07-31-2024	6.11:8.1.0	Doc ID: RM100000001GWKX
Model Year Start: 2020	Model: GR Corolla	Prod Date Range: [01/2019 - 09/2019]
Title: AUDIO / VIDEO: AUDIO AND VISUAL SYSTEM (for Gasoline Model with Dual Knob Type): B15DB; Telematics Transceiver Disconnected; 2020 MY Corolla Corolla Hatchback GR Corolla [01/2019 - 09/2019]

DTC

B15DB

Telematics Transceiver Disconnected

DESCRIPTION

If the radio and display receiver assembly cannot detect the DCM (telematics transceiver) for a certain period of time (90 seconds) after the ignition switch is turned to ACC and the radio and display receiver assembly confirms that the information is missing by checking past DCM (telematics transceiver) recognition information (registered information), this DTC will be stored.

The telematics system uses USB communication between devices. If an open, short, short to +B or short to ground occurs in the USB circuit, communication is interrupted and the telematics system will not operate normally.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
B15DB	Telematics Transceiver Disconnected	DCM (telematics transceiver) disconnected	Harness or connector DCM (telematics transceiver) DCM (telematics transceiver) power source circuit Radio and display receiver assembly

HINT:

This DTC may be stored due to environmental reasons such as electrical noise or interference.

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 Audio and Visual System.
Click here
When replacing the radio and display receiver assembly, always replace it with a new one. If a radio and display receiver assembly which was installed to another vehicle is used, the following may occur:
- A communication malfunction DTC may be stored.
- The radio and display receiver assembly may not operate normally.
Inspect the fuses for circuits related to this system before performing the following procedure.
Before replacing the DCM (telematics transceiver), refer to Registration.
Click here

PROCEDURE

1.	CHECK HARNESS AND CONNECTOR (DCM (TELEMATICS TRANSCEIVER) POWER SOURCE)

(a) Disconnect the I72 DCM (telematics transceiver) connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
I72-4 (E) - Body ground	Always	Below 1 Ω

Standard Voltage:

Tester Connection	Condition	Specified Condition
I72-1 (+B) - I72-4 (E)	Always	11 to 14 V
I72-8 (ACC) - I72-4 (E)	Ignition switch ACC	11 to 14 V
I72-7 (IG2) - I72-4 (E)	Ignition switch ON	11 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR

2.	INSPECT RADIO AND DISPLAY RECEIVER ASSEMBLY

(a) Disconnect the I57 radio and display receiver assembly connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
I57-11 (USBG) - Body ground	Always	Below 1 Ω

*a	Component without harness connected (Radio and Display Receiver Assembly)

Standard Voltage:

Tester Connection	Condition	Specified Condition
I57-10 (USBV) - I57-11 (USBG)	Ignition switch ON	4.75 to 5.25 V

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY

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

(a) Disconnect the I57 radio and display receiver assembly connector.

(b) Disconnect the t1 DCM (telematics transceiver) connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
I57-10 (USBV) - t1-5 (USBV)	Always	Below 1 Ω
I57-11 (USBG) - t1-3 (USBG)	Always	Below 1 Ω
I57-10 (USBV) or t1-5 (USBV) - Body ground	Always	10 kΩ or higher
I57-11 (USBG) or t1-3 (USBG) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

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

(a) Check the installation condition.

(1) Check the USB communication lines between the radio and display receiver assembly and DCM (telematics transceiver) for any installation or connection problems.

(b) Disconnect the t2 radio and display receiver assembly connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
t2-1 (USB+) - t1-2 (USB+)	Always	Below 1 Ω
t2-2 (USB-) - t1-1 (USB-)	Always	Below 1 Ω
t2-3 (USBS) - t1-6 (USBS)	Always	Below 1 Ω
t2-1 (USB+) or t1-2 (USB+) - Body ground	Always	10 kΩ or higher
t2-2 (USB-) or t1-1 (USB-) - Body ground	Always	10 kΩ or higher
t2-3 (USBS) or t1-6 (USBS) - Body ground	Always	10 kΩ or higher

Front view of wire harness connector

(to DCM (Telematics Transceiver))

Front view of wire harness connector

(to Radio and Display Receiver Assembly)

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.	REPLACE DCM (TELEMATICS TRANSCEIVER)

(a) Replace the DCM (telematics transceiver) with a new one.

Click here

(b) Clear the DTCs.

Body Electrical > Navigation System > Clear DTCs

(d) Turn the ignition switch to IG and wait for 90 seconds.

(e) Recheck for DTCs and check that no DTCs are output.

Body Electrical > Navigation System > Trouble Codes

OK:

No DTCs are output.

END

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY