Toyota Tundra. Manual — part 2423

This DTC is output when refrigerant pressure is extremely low (196 kPa (2.0 kgf/cm

2

, 28 psi) or less) or

extremely high (3140 kPa (32.0 kgf/cm

2

, 455 psi) or more). The pressure switch, which is installed on the pipe

of the high pressure side to detect refrigerant pressure, outputs a refrigerant pressure signal to the air
conditioning amplifier.

The air conditioning amplifier controls the compressor according to the sensor characteristic.

HINT:

Be sure to check the refrigerant volume first when this DTC is output because this DTC can also be output if
there is no refrigerant in the system.

DTC DETECTION CONDITION CHART

WIRING DIAGRAM

Fig. 117: Pressure Sensor - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

INSPECTION PROCEDURE

HINT:

Be sure to check the refrigerant volume first when this DTC is output because this DTC can also be output if

DTC

DTC Detection Condition

Trouble Area

B1423/23

Open or short in pressure switch

circuit



Air conditioning pressure
switch



Harness and connector



Air conditioning amplifier

2009 Toyota Tundra

2009 HVAC Air Conditioning - Tundra

there is no refrigerant in the system.

1. CHECK HARNESS OR CONNECTOR (A/C PRESSURE SWITCH - A/C AMPLIFIER AND

BODY GROUND)

a. Disconnect the A20 air conditioning pressure switch connector.

Fig. 118: Identifying Terminals Of A20 Air Conditioning Pressure Switch Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

b. Disconnect the J19 air conditioning amplifier connector.

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

Standard Resistance

TESTER CONNECTION SPECIFIED CONDITION CHART

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to Next Step

Tester Connection

Condition Specified Condition

A20-1 - J19-9 (PSW)

Always

Below 1 ohms

A20-1 or J19-9 (PSW) - Body ground Always

10 kohms or higher

A20-2 - Body ground

Always

Below 1 ohms

2009 Toyota Tundra

2009 HVAC Air Conditioning - Tundra

2. CHECK AIR CONDITIONING PRESSURE SWITCH

a. Set the manifold gauge set.

b. Disconnect the air conditioning pressure switch connector.

Fig. 119: Locating Air Conditioning Pressure Switch Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

c. Run the engine at approximately 2000 RPM.

d. Set the blower speed control switch to the HI position.

e. Set the temperature control level to the MAX. COOL position.

f. Turn the A/C switch ON.

g. Check the switch operation.

1. Connect the positive (+) lead from an ohmmeter to terminal 1 and the negative (-) lead to

terminal 2.

2. Measure the resistance between the terminals when refrigerant pressure is changed, as shown

in the illustration.

Fig. 120: Air Conditioning Pressure Switch Continuity Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

OK:

2009 Toyota Tundra

2009 HVAC Air Conditioning - Tundra

Resistance varies as shown in the illustration.

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: REPLACE AIR CONDITIONING PRESSURE SWITCH (See REMOVAL )

DTC B1441/41 AIR MIX DAMPER CONTROL SERVO MOTOR CIRCUIT (PASSENGER SIDE)

DESCRIPTION

The air mix damper servo motor (for passenger 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 passenger 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 passenger side is controlled.

DTC DETECTION CONDITION CHART

WIRING DIAGRAM

Result

Proceed to

NG

A

OK (Checking from the PROBLEM SYMPTOMS TABLE)

B

OK (Checking from the DTC)

C

DTC

DTC Detection Condition

Trouble Area

B1441/41

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



Air mix servo motor (for
passenger side)



Air conditioning harness



Air conditioning amplifier

2009 Toyota Tundra

2009 HVAC Air Conditioning - Tundra