Toyota Tundra. Manual — part 2418

If the result is not as specified, the ECU may have a malfunction.

b. Using an oscilloscope, check waveform 1.

Compressor lock signal

WAVEFORM REFERENCE

J19-13 (SG-2) -

Body ground

G - Body

ground

Ground for ambient
temperature sensor

Always

Below 1 ohms

J19-37 (LIN1) -

J19-14 (GND)

SB - W-B

LIN communication

signal

Ignition switch ON

Pulse generation

J19-11 (CANH)

- J19-14 (GND)

B - W-B

Hi-level CAN bus line

Ignition switch ON

Pulse generation
(see waveform 3

c)

J19-12 (CANL)
- J19-14 (GND)

W - W-B

Lo-level CAN bus line

Ignition switch ON

Pulse generation
(see waveform 4

d)

z1-2 (BUS G) -

Body ground

-

Ground for BUS IC

Always

Below 2 V

z1-3 (BUS) - 21-

2 (BUS G)

-

BUS IC control signal

Ignition switch OFF -->

ON

Pulse generation

z1-4 (BBUS) -

z1-2 (BUS G)

-

Power supply for BUS

IC

Always

11 to 14 V

z1-5 (SGA) -
Body ground

-

Ground for evaporator
temperature sensor

Always

Below 2 V

z1-6 (TEA) - z1-

5 (SGA)

-

A/C evaporator
temperature sensor
signal

Ignition switch ON
Evaporator temperature
at 0°C (32°F)

1.7 to 2.1 V

z1-6 (TEA) - z1-

5 (SGA)

-

A/C evaporator
temperature sensor
signal

Ignition switch ON
Evaporator temperature
at 15°C (59°F)

0.7 to 1.3 V

Terminal No. (Symbols)

Tool Setting

Condition

J19-8 (LOCK) - J19-14 (GND) 200 mV/DIV., 10 ms./DIV.

Engine is running Blower switch LO

A/C switch ON

2009 Toyota Tundra

2009 HVAC Air Conditioning - Tundra

Fig. 102: Identifying Waveform 1
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

c. Using an oscilloscope, check waveform 2.

Blower motor control signal

WAVEFORM REFERENCE

Fig. 103: Identifying Waveform 2
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

HINT:

When the blower level is increased, the duty ratio changes accordingly.

d. Using an oscilloscope, check waveform 3.

CAN communication signal

WAVEFORM REFERENCE

Fig. 104: Identifying Waveform 3

Terminal No. (Symbols)

Tool Setting

Condition

J19-23 (BLW) - J19-14 (GND) 1 V/DIV, 500 µsec./DIV.

Ignition switch ON

Blower switch LO

Terminal No. (Symbols)

Tool Setting

Condition

J19-11 (CANH) - J19-14 (GND) 1 V/DIV., 10 µsec./DIV. Ignition switch ON

2009 Toyota Tundra

2009 HVAC Air Conditioning - Tundra

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

HINT:

The waveform varies depending on the CAN communication signal.

e. Using an oscilloscope, check waveform 4.

CAN communication signal

WAVEFORM REFERENCE

Fig. 105: Identifying Waveform 4
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

HINT:

The waveform varies depending on the CAN communication signal.

2. CHECK INTEGRATION CONTROL AND PANEL

Fig. 106: Identifying Terminals Of J37 Integration Control And Panel Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

a. Disconnect the J37 integration control and panel connector.

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

Terminal No. (Symbols)

Tool Setting

Condition

J19-12 (CANL) - J19-14 (GND) 1 V/DIV., 10 µsec./DIV. Ignition switch ON

2009 Toyota Tundra

2009 HVAC Air Conditioning - Tundra

CONNECTOR TERMINALS REFERENCE

If the result is not as specified, there may be a malfunction on the wire harness side.

DTC CHECK/CLEAR

1. CHECK DTC

a. Connect the Techstream to the DLC3.

b. Turn the ignition switch ON.

c. Turn the Techstream on.

d. Enter the following menus: Body Electrical/Air conditioner/Trouble Codes.

e. Read the DTCs.

2. CLEAR DTC

a. Connect the Techstream to the DLC3.

b. Turn the ignition switch ON.

c. Turn the Techstream on.

d. Enter the following menus: Body Electrical/Air conditioner/Trouble Codes.

e. Erase the DTCs.

DATA LIST/ACTIVE TEST

1. READ DATA LIST

HINT:

Using the Techstream to read the Data List allows the values or states of switches, sensor, actuators and
other items to be read without removing any parts. This non-intrusive inspection can be very useful
because intermittent conditions or signals may be discovered before parts or wiring is disturbed. Reading
the Data List information early in troubleshooting is one way to save diagnostic time.

Terminal No.

(Symbols)

Wiring Color Terminal Description

Condition

Specified

Condition

J37-16 (IG+) - J37-1

(GND)

P - W-B

Ignition power supply

Ignition switch

ON

11 to 14 V

Ignition switch

OFF

Below 1 V

J37-1 (GND) - Body

ground

W-B - Body

ground

Ground

Always

Below 1 ohms

J37-3 (STX) - J37-1

(GND)

SB - W-B

LIN communication

signal

Ignition switch

ON

Pulse generation

NOTE:

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.

2009 Toyota Tundra

2009 HVAC Air Conditioning - Tundra