Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: Short in Telephone SUB Antenna Circuit (B1536,B1537)

DESCRIPTION

These DTCs are stored when the DCM (Telematics Transceiver) detects an open or a short in the telephone and GPS antenna assembly (for Front Side) circuit. The DCM (Telematics Transceiver) oscillates and receives 824 - 894 MHz or 1850 - 1990 MHz radio-frequency through the telephone and GPS antenna assembly (for Front Side).

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

B1536

Short in Telephone SUB Antenna Circuit

Telephone and GPS antenna assembly (for Front Side) impedance is lower than malfunction criterion for 10 seconds when power switch is on (IG).

(Short circuit)

  • DCM (Telematics Transceiver)
  • Telephone and GPS antenna assembly (for Front Side)
  • Telephone and GPS antenna cord (No. 4 antenna cord sub-assembly)
  • Telephone and GPS antenna cord (No. 6 antenna cord sub-assembly)

B1537

Open in Telephone SUB Antenna Circuit

Telephone and GPS antenna assembly (for Front Side) impedance is higher than malfunction criterion for 10 seconds when power switch is on (IG).

(Open circuit)

  • DCM (Telematics Transceiver)
  • Telephone and GPS antenna assembly (for Front Side)
  • Telephone and GPS antenna cord (No. 4 antenna cord sub-assembly)
  • Telephone and GPS antenna cord (No. 6 antenna cord sub-assembly)

WIRING DIAGRAM

CAUTION / NOTICE / HINT

HINT:

  • Before performing this diagnostic procedure, make sure to perform Health Check and confirm that the DCM/VIN registration information is correct.

    Click here

  • Refer to "PARTS LOCATION" for the installation location of telephone and GPS antenna cord.

    Click here

PROCEDURE

1.

CHECK DTC

(a) Turn the power switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the power switch on (IG) and wait for 10 seconds.

(d) Turn the Techstream on.

(e) Clear the DTCs.

Body Electrical > Telematics > Clear DTCs

(f) Recheck for DTCs.

Body Electrical > Telematics > Trouble Codes

Result

Proceed to

DTC B1536 or B1537 is output

A

DTC B1536 or B1537 is not output

B

B

CHECK FOR INTERMITTENT PROBLEMS

A

2.

INSPECT TELEPHONE AND GPS ANTENNA ASSEMBLY (for Front Side)

(a) Disconnect the telephone and GPS antenna assembly (for Front Side) connector.

*a

Component without harness connected

(Telephone and GPS Antenna Assembly (for Front Side))

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

4 - 4a

Always

4 to 11 kΩ

NG

REPLACE TELEPHONE AND GPS ANTENNA ASSEMBLY (for Front Side)

OK

3.

INSPECT TELEPHONE AND GPS ANTENNA CORD (NO. 4 ANTENNA CORD SUB-ASSEMBLY)

(a) Disconnect the F telephone and GPS antenna cord (No. 4 antenna cord sub-assembly) connector.

*a

Component without harness connected (Telephone and GPS Antenna Cord (No. 4 Antenna Cord Sub-assembly))

(b) Disconnect the E telephone and GPS antenna cord (No. 4 antenna cord sub-assembly) connector.

*a

Component without harness connected (Telephone and GPS Antenna Cord (No. 4 Antenna Cord Sub-assembly))

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

F-4 - E-3

Always

Below 1 Ω

F-4 or E-3 - Body ground

Always

10 kΩ or higher

F-4a - E-3a

Always

Below 1 Ω

F-4a or E-3a - Body ground

Always

10 kΩ or higher

NG

REPLACE TELEPHONE AND GPS ANTENNA CORD (NO. 4 ANTENNA CORD SUB-ASSEMBLY)

OK

4.

INSPECT TELEPHONE AND GPS ANTENNA CORD (NO. 6 ANTENNA CORD SUB-ASSEMBLY)

(a) Disconnect the D telephone and GPS antenna cord (No. 6 antenna cord sub-assembly) connector.

*a

Component without harness connected (Telephone and GPS Antenna Cord (No. 6 Antenna Cord Sub-assembly))

(b) Disconnect the A telephone and GPS antenna cord (No. 6 antenna cord sub-assembly) connector.

*a

Component without harness connected (Telephone and GPS Antenna Cord (No. 6 Antenna Cord Sub-assembly))

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

D-1 - A-1

Always

Below 1 Ω

D-1 or A-1 - Body ground

Always

10 kΩ or higher

D-1a - A-1a

Always

Below 1 Ω

D-1a or A-1a - Body ground

Always

10 kΩ or higher

NG

REPLACE TELEPHONE AND GPS ANTENNA CORD (NO. 6 ANTENNA CORD SUB-ASSEMBLY)

OK

5.

REPLACE TELEPHONE AND GPS ANTENNA ASSEMBLY (for Front Side)

(a) Replace the telephone and GPS antenna assembly (for Front Side) with a known good one and check if the same problem occurs again.

Click here

OK:

The system returns to normal.

OK

END

NG

6.

REPLACE DCM (TELEMATICS TRANSCEIVER)

(a) Replace the DCM (Telematics Transceiver).

Click here

NOTICE:

  • The power switch must be off.
  • Do not swap the DCM (Telematics Transceiver) with one from another vehicle.
NEXT

PERFORM DCM ACTIVATION

    Backup Battery Degradation (B15EC)

    Manual (SOS) Switch Red Indicator Malfunction (B1570)

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