Toyota Tundra. Manual — part 2406

The air mix damper servo motor (for driver side) sends pulse signals to inform the air conditioning amplifier of
the damper position. The air conditioning amplifier activates the motor (normal, reverse) based on the signals to
move the air mix damper (for driver side) to any position. As a result the amount of air that has passed through
the evaporator and is now passing through the heater core is adjusted, and the temperature of the air blowing
toward the driver side is controlled.

HINT:

Confirm that no mechanical problem is present because this diagnostic trouble code can be output when either a
damper link or damper is mechanically locked.

DTC DETECTION CONDITION CHART

WIRING DIAGRAM

Fig. 62: Air Mix Damper Control Servo Motor - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

INSPECTION PROCEDURE

1. READ VALUE USING TECHSTREAM (AIR MIX SERVO MOTOR TARGET PULSE (for

Driver Side))

a. Use the Data List to check if the servo motor is functioning properly.

Air Conditioner

DTC

DTC Detection Condition

Trouble Area

B1446/46

Air mix damper position sensor
value does not change even if air
conditioning amplifier operates air
mix servo motor



Air mix servo motor (for
driver side)



Air conditioning harness



Air conditioning amplifier

2009 Toyota Tundra

2009 HVAC Air Conditioning - Tundra

DATA LIST

OK:

The display is as specified in the normal condition.

Result

RESULT REFERENCE

B: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE (See PROBLEM SYMPTOMS TABLE )

C: REPLACE AIR CONDITIONING AMPLIFIER (See REMOVAL )

A: Go to Next Step

2. REPLACE AIR MIX SERVO MOTOR (for Driver Side)

a. Temporarily replace the air mix servo motor with a new one (see DISASSEMBLY ).

HINT:

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

3. CHECK FOR DTC

a. Clear the DTC (see DTC CHECK/CLEAR ).

b. Check for DTC (see DTC CHECK/CLEAR ).

OK:

DTC is not output.

NG: Go to step 4

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic

Note

Air Mix Servo Targ

Pulse (D)

Driver side air mix servo motor target
pulse/Min.: 5
Max.: 104

MAX. COLD: 5
(pulse)
MAX. HOT: 104
(pulse)

-

Result

Proceed to

NG

A

OK (Checking from the PROBLEM SYMPTOMS TABLE)

B

OK (Checking from the DTC)

C

2009 Toyota Tundra

2009 HVAC Air Conditioning - Tundra

OK: END (AIR MIX SERVO MOTOR IS DEFECTIVE)

4. REPAIR OR REPLACE AIR CONDITIONING HARNESS

a. Repair or replace the air conditioning harness.

5. CHECK FOR DTC

a. Clear the DTC (see DTC CHECK/CLEAR ).

b. Check for DTC again (see DTC CHECK/CLEAR ).

OK:

DTC is not output.

NG: REPLACE AIR CONDITIONING AMPLIFIER (See REMOVAL )

OK: END

DTC B1497/97 BUS IC COMMUNICATION MALFUNCTION

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 DETECTION CONDITION CHART

WIRING DIAGRAM

DTC

DTC Detection Condition

Trouble Area

B1497/97

Communication line error or open



Air conditioning harness



Air conditioning amplifier

2009 Toyota Tundra

2009 HVAC Air Conditioning - Tundra

Fig. 63: BUS IC Communication Malfunction - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

INSPECTION PROCEDURE

1. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BODY

GROUND)

a. Disconnect the J19 air conditioning amplifier connector.

Fig. 64: Identifying Terminals Of J19 Air Conditioning Amplifier Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

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

Standard Resistance

TESTER CONNECTION SPECIFIED CONDITION CHART

2009 Toyota Tundra

2009 HVAC Air Conditioning - Tundra