Toyota Tundra Service Manual: Passenger Side Cool Air Bypass Damper Control (B1445/45)

DESCRIPTION

HINT:

Although the tester title says "Passenger Side", there is only one cool air bypass servo motor on this vehicle.

The cool air bypass servo motor 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 cool air bypass servo motor to any position. As a result, when the air conditioner is operating, the temperature of the air blowing toward the passenger's head area 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 Code

DTC Detection Condition

Trouble Area

B1445/45

Cool air bypass servo motor position sensor value does not change even if air conditioning amplifier operates cool air bypass servo motor

  • Cool air bypass servo motor
  • Air conditioning harness
  • Air conditioning amplifier

WIRING DIAGRAM

PROCEDURE

1.

READ VALUE USING TECHSTREAM (COOL AIR BYPASS SERVO MOTOR TARGET PULSE)

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

Air Conditioner

Tester Display

Measurement Item / Range

Normal Condition

Diagnostic Note

Cool Air Bypass Pulse

Cool air bypass servo motor target pulse /

Min.: 0, Max.: 255

Open: 8 (pulse)

Close: 50 (pulse)

-

OK:

The display is as specified in the normal condition.

Result

Result

Proceed to

OK (Checking from the DTC)

A

OK (Checking from the PROBLEM SYMPTOMS TABLE)

B

NG

C

B

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

C

REPLACE AIR CONDITIONING AMPLIFIER

A

2.

REPLACE COOL AIR BYPASS SERVO MOTOR (for Passenger Side)

(a) Temporarily replace the cool air bypass servo motor 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

3.

CHECK FOR DTC

(a) Clear the DTC (see page ).

(b) Check for DTC (see page ).

OK:

DTC is not output.

OK

END (COOL AIR BYPASS SERVO MOTOR IS DEFECTIVE)

NG

4.

REPLACE AIR CONDITIONING HARNESS

(a) Replace the air conditioning harness.

NEXT

5.

CHECK FOR DTC

(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

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    See More:

    Toyota Tundra Service Manual > Audio And Visual System: Data List / Active Test
    DATA LIST / ACTIVE TEST 1. DATA LIST NOTICE: In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not. HINT: Using the Techstream to read the Data List allows the values or states ...

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