Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Backup Battery Internal Electronic Failure (B15CC49)

DESCRIPTION

This DTC is set when the DCM (telematics transceiver) detects one of the following:

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
B15CC49	Backup Battery Internal Electronic Failure	Mobilephone battery malfunction	Mobilephone battery DCM (telematics transceiver)

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 Safety Connect System.

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PROCEDURE

1.

CHECK DTC

(a) Turn the engine switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the engine switch on (IG) and wait for 10 seconds or more.

(d) Turn the Techstream on.

(e) Clear the DTCs.

Body Electrical > Telematics > Clear DTCs

(f) Check for DTCs and check that no DTCs are output.

Body Electrical > Telematics > Trouble Codes

OK

USE SIMULATION METHOD TO CHECK

NG

2.	CHECK MOBILEPHONE BATTERY

(a) Replace the mobilephone battery with a normal one and check if the same problem occurs again.

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NOTICE:

The mobilephone battery must not be replaced while an ACN call is in progress.

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(b) Clear the DTCs.

Body Electrical > Telematics > Clear DTCs

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

Body Electrical > Telematics > Trouble Codes

OK:

No DTCs are output.

OK

PERFORM INITIALIZATION

NG

3.	REPLACE DCM (TELEMATICS TRANSCEIVER)

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

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NEXT

PERFORM DCM ACTIVATION