Toyota Tundra Service Manual: Air Mix Damper Control Servo Motor Circuit (Driver Side) (B1446/46)

DESCRIPTION

The No. 1 damper servo sub-assembly (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.

WIRING DIAGRAM

PROCEDURE

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

OK:

The display is as specified in the normal condition.

B

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

C

REPLACE AIR CONDITIONING AMPLIFIER

A

(a) Temporarily replace the No. 1 damper servo sub-assembly (air mix damper servo motor [for driver side]) with a new one (see page ).

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.

NEXT

(a) Clear the DTC (see page ).

(b) Check for DTC (see page ).

OK:

DTC is not output.

OK

END (AIR MIX SERVO MOTOR IS DEFECTIVE)

NG

(a) Replace the air conditioning harness.

NEXT

(a) Clear the DTC (see page ).

(b) Check for DTC again (see page ).

OK:

DTC is not output.

OK

END (AIR CONDITIONING HARNESS IS DEFECTIVE)

NG

REPLACE AIR CONDITIONING AMPLIFIER