Toyota Tundra Service Manual: BUS IC Communication Malfunction (B1497/97)

DESCRIPTION

The air conditioning harness connects the air conditioning amplifier and each servo motor. The air conditioning amplifier supplies power and sends operation instructions to each servo motor through the air conditioning harness. Each servo motor sends the damper position information to the air conditioning amplifier.

DTC Code

DTC Detection Condition

Trouble Area

B1497/97

Communication line error or open

  • Air conditioning harness
  • No. 1 damper servo sub-assembly (air mix damper servo motor [for driver side])
  • No. 1 damper servo sub-assembly (air outlet servo motor)
  • Air mix servo motor (for passenger side)
  • Air inlet servo motor
  • Air cool bypass servo motor
  • Air conditioning amplifier
  • Harness or connector

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1.

PERFORM ACTIVE TEST USING TECHSTREAM

(a) Select the Active Test, using the Techstream to generate a control command, and then check that the servo motor operates.

Air Conditioner

Tester Display

Test Part

Control Range

Diagnostic Note

Air Mix Servo Targ Pulse (D)

No. 1 damper servo sub-assembly (air mix servo motor [for driver side]) pulse

Min.: 5, Max.: 104

-

Air Mix Servo Targ Pulse (P)

Passenger side air mix servo motor pulse

Min.: 6, Max.: 105

-

Air Outlet Servo Pulse (D)

No. 1 damper servo sub-assembly (air outlet servo motor) pulse

Min.: 9, Max.: 97

-

Air Inlet Damper Targ Pulse

Air inlet damper target pulse

Min.: 7, Max.: 28

-

Cool Air Bypass Pulse

Driver side cool air bypass pulse

Min.: 8, Max.: 50

-

OK:

Arm of the servo motor selected in the Active Test moves smoothly

Result

Result

Proceed to

One of the servo motors is malfunctioning

A

All of the servo motor are malfunctioning

B

B

GO TO STEP 8

A

2.

SYSTEM CHECK

(a) According to the test, proceed to the next step.

Result

Result

Proceed to

Only the No. 1 damper servo sub-assembly (air mix servo motor [for driver side]) is malfunctioning

A

Only the air mix servo motor (for passenger side) is malfunctioning

B

Only the No. 1 damper servo sub-assembly (air outlet servo motor) is malfunctioning

C

Only the air inlet servo motor is malfunctioning

D

Only the cool air bypass servo motor is malfunctioning

E

B

GO TO STEP 4

C

GO TO STEP 5

D

GO TO STEP 6

E

GO TO STEP 7

A

3.

CHECK NO. 1 DAMPER SERVO SUB-ASSEMBLY (AIR MIX SERVO MOTOR [FOR DRIVER SIDE])

(a) Replace the No. 1 damper servo sub-assembly (air mix servo motor [for driver side]) (See page ).

HINT:

Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a new or a known good one and check that the condition returns to normal.

(b) Check for DTC (See page ).

Result

Result

Proceed to

DTC B1497/97 is not output

A

DTC B1497/97 is output

B

A

END (NO. 1 DAMPER SERVO SUB-ASSEMBLY [AIR MIX SERVO MOTOR (FOR DRIVER SIDE)] IS DEFECTIVE)

B

GO TO STEP 8

4.

CHECK AIR MIX SERVO MOTOR (FOR PASSENGER SIDE)

(a) Replace the air mix servo motor (for passenger side) (See page ).

HINT:

Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a new or a known good one and check that the condition returns to normal.

(b) Check for DTC (See page ).

Result

Result

Proceed to

DTC B1497/97 is not output

A

DTC B1497/97 is output

B

A

END (AIR MIX SERVO MOTOR [FOR PASSENGER SIDE] IS DEFECTIVE)

B

GO TO STEP 8

5.

CHECK NO. 1 DAMPER SERVO SUB-ASSEMBLY (AIR OUTLET SERVO MOTOR)

(a) Replace the No. 1 damper servo sub-assembly (air outlet servo motor) (See page ).

HINT:

Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a new or a known good one and check that the condition returns to normal.

(b) Check for DTC (See page ).

Result

Result

Proceed to

DTC B1497/97 is not output

A

DTC B1497/97 is output

B

A

END (NO. 1 DAMPER SERVO SUB-ASSEMBLY [AIR OUTLET SERVO MOTOR] IS DEFECTIVE)

B

GO TO STEP 8

6.

CHECK AIR INLET SERVO MOTOR

(a) Replace the air inlet servo motor (See page ).

HINT:

Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a new or a known good one and check that the condition returns to normal.

(b) Check for DTC (See page ).

Result

Result

Proceed to

DTC B1497/97 is not output

A

DTC B1497/97 is output

B

A

END (AIR INLET SERVO MOTOR IS DEFECTIVE)

B

GO TO STEP 8

7.

CHECK COOL AIR BYPASS SERVO MOTOR

(a) Replace the cool air bypass servo motor (See page ).

HINT:

Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a new or a known good one and check that the condition returns to normal.

(b) Check for DTC (See page ).

Result

Result

Proceed to

DTC B1497/97 is not output

A

DTC B1497/97 is output

B

A

END (COOL AIR BYPASS SERVO MOTOR IS DEFECTIVE)

B

8.

CHECK AIR CONDITIONING HARNESS

(a) Replace the air conditioning harness.

HINT:

Since the air conditioning harness cannot be inspected while it is removed from the vehicle, replace the air conditioning harness with a new or a known good one and check that the condition returns to normal.

(b) Check for DTC (See page ).

Result

Result

Proceed to

DTC B1497/97 is not output

A

DTC B1497/97 is output

B

A

END (AIR CONDITIONING HARNESS IS DEFECTIVE)

B

9.

CHECK HARNESS AND CONNECTOR (POWER SOURCE)

(a) Disconnect the J19 air conditioning amplifier connector.

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

Standard voltage:

Tester Connection

Condition

Specified Condition

J19-21 (B) - Body ground

Always

11 to 14 V

OK

REPLACE AIR CONDITIONING AMPLIFIER

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

    Air Mix Damper Control Servo Motor Circuit (Driver Side) (B1446/46)

    Multiplex Communication Circuit (B1499/99)

    See More:

    Toyota Tundra Service Manual > Rear Door(for Crewmax): Disassembly
    DISASSEMBLY CAUTION / NOTICE / HINT HINT: Use the same procedures for the RH side and LH side. The procedures listed below are for the LH side. PROCEDURE 1. PRECAUTION NOTICE: After turning the ignition switch off, waiting time may be required before disconnecting the cable from the battery terminal ...

    Toyota Tundra Owners Manual

    Toyota Tundra Service Manual

    © 2021 Copyright www.ttundra.com
    0.0206