Toyota Tundra Service Manual: Terminals Of Ecu

TERMINALS OF ECU

CHECK TRANSPONDER KEY ECU ASSEMBLY

(a) Disconnect the J26 transponder key ECU assembly connector.

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

HINT:

Measure the values on the wire harness side with the connector disconnected.

Tester Connection

Input/Output

Wiring Color

Terminal Description

Condition

Specified Condition

Related Data List Item

J26-5 (GND) - Body ground

-

W-B - Body ground

Ground

Always

Below 1 Ω

-

J26-1 (+B) - J26-5 (GND)

Input

G - W-B

Battery

Always

11 to 14 V

+B

J26-2 (IG) - J26-5 (GND)

Input

L - W-B

Ignition switch

Ignition switch off

Below 1 V

IG SW

Ignition switch ON

11 to 14 V

J26-3 (KSW) - J26-5 (GND)

Input

B - W-B

Unlock warning switch signal

No key in ignition key cylinder

10 kΩ or higher

Key SW/B2780

Key in ignition key cylinder

Below 1 Ω

(c) Reconnect the J26 transponder key ECU assembly connector.

(d) Measure the voltage and check for pulses according to the value(s) in the table below.

Tester Connection

Input/Output

Wiring Color

Terminal Description

Condition

Specified Condition

Related Data List Item

J26-8 (IND) - J26-5 (GND)

Output

V - W-B

Security indicator light signal

No key in ignition key cylinder, or 20 seconds elapsed after turning ignition switch to ACC or off (engine immobiliser system set)

Pulse generation

Immobiliser

Key in ignition key cylinder (engine immobiliser system unset)

Below 1 V

J26-9 (D) - J26-5 (GND)

Input/Output

BE - W-B

DLC3 communication

Without communication

Below 1 V

-

During communication

Pulse generation

J26-4 (ANT1) - J26-5 (GND)

Input/Output

LG - W-B

Transponder key amplifier power source

No key in ignition key cylinder

4 to 6 V

-

Within 3 seconds of inserting key into ignition key cylinder

Pulse generation

(See waveform 1)

J26-15 (ANT2) - J26-5 (GND)

Input/Output

V - W-B

Transponder key amplifier communication signal

No key in ignition key cylinder

4 to 6 V

-

Within 3 seconds of inserting key into ignition key cylinder

Pulse generation

(See waveform 2)

J26-12 (EFII) - J26-5 (GND)

Input

R - W-B

ECM input signal

Within 3 seconds of starter operation and initial combustion, or within 3 seconds of ignition switch first being turned to ON after cable disconnected and reconnected to negative (-) battery terminal

Pulse generation

(See waveform 3)

E/G Start Permission

J26-13 (EFIO) - J26-5 (GND)

Output

G - W-B

ECM output signal

Ignition switch off

Below 1 V

E/G Start Permission

Within 3 seconds of starter operation and initial combustion, or within 3 seconds of ignition switch first being turned to ON after cable disconnected and reconnected to negative (-) battery terminal

Pulse generation

(See waveform 4)

(e) Using an oscilloscope, check the waveform.

(1) Waveform 1 (Reference)

Tester Connection

J26-4 (ANT1) - J26-5 (GND)

Tool Setting

20 V/DIV., 2 s./DIV.

Condition

Within 3 seconds of inserting key into ignition key cylinder

(2) Waveform 2 (Reference)

Tester Connection

J26-15 (ANT2) - J26-5 (GND)

Tool Setting

20 V/DIV., 2 s./DIV.

Condition

Within 3 seconds of inserting key into ignition key cylinder

(3) Waveform 3 (Reference)

*a

Approximately 160 ms

*b

Approximately 510 ms

Tester Connection

J26-12 (EFII) - J26-5 (GND)

Tool Setting

2 V/DIV., 500 ms./DIV.

Condition

Within 3 seconds of starter operation and initial combustion, or within 3 seconds of ignition switch first being turned to ON after cable disconnected and reconnected to negative (-) battery terminal

(4) Waveform 4 (Reference)

*a

Approximately 160 ms

*b

Approximately 510 ms

Tester Connection

J26-13 (EFIO) - J26-5 (GND)

Tool Setting

2 V/DIV., 500 ms./DIV.

Condition

Within 3 seconds of starter operation and initial combustion, or within 3 seconds of ignition switch first being turned to ON after cable disconnected and reconnected to negative (-) battery terminal

HINT:

The standard voltage between each pair of ECM terminals is shown in the table below. The appropriate conditions for checking each pair of terminals are also indicated. The result of checks should be compared with the standard voltage for that pair of terminals, displayed in the "Specified Condition" column. The illustration above can be used as a reference to identify the ECM terminal locations.

CHECK ECM

(a) Measure the resistance, voltage and check for pulses according to the value(s) in the table below.

Tester Connection

Input/Output

Wiring Color

Terminal Description

Condition

Specified Condition

Related Data List Item

A24-29 (IMO) - D74-81 (E1)*1

A24-48 (IMO) - D74-81 (E1)*2

Output

P - BR

Transponder key ECU assembly output signal

Ignition switch off

11 to 14 V

E/G Start Permission

Within 3 seconds of starter operation and initial combustion, or within 3 seconds of ignition switch first being turned to ON after cable disconnected and reconnected to negative (-) battery terminal

Pulse generation

(See waveform 1)

E/G Start Permission

A24-40 (IMI) - D74-81 (E1)*1

A24-46 (IMI) - D74-81 (E1)*2

Input

B - BR

Transponder key ECU assembly input signal

Ignition switch off

Below 1 V

E/G Start Permission

Within 3 seconds of starter operation and initial combustion, or within 3 seconds of ignition switch first being turned to ON after cable disconnected and reconnected to negative (-) battery terminal

Pulse generation

(See waveform 2)

E/G Start Permission

  • *1: for 1UR-FE
  • *2: for 3UR-FE, 3UR-FBE

(b) Using an oscilloscope, check the waveform.

(1) Waveform 1 (Reference)

*a

Approximately 160 ms

*b

Approximately 510 ms

Tester Connection

A24-29 (IMO) - D74-81 (E1)*1

A24-48 (IMO) - D74-81 (E1)*2

Tool Setting

2 V/DIV., 500 ms./DIV.

Condition

Within 3 seconds of starter operation and initial combustion, or within 3 seconds of ignition switch first being turned to ON after cable disconnected and reconnected to negative (-) battery terminal

  • *1: for 1UR-FE
  • *2: for 3UR-FE, 3UR-FBE

(2) Waveform 2 (Reference)

*a

Approximately 160 ms

*b

Approximately 510 ms

Tester Connection

A24-40 (IMI) - D74-81 (E1)*1

A24-46 (IMI) - D74-81 (E1)*2

Tool Setting

2 V/DIV., 500 ms./DIV.

Condition

Within 3 seconds of starter operation and initial combustion, or within 3 seconds of ignition switch first being turned to ON after cable disconnected and reconnected to negative (-) battery terminal

  • *1: for 1UR-FE
  • *2: for 3UR-FE, 3UR-FBE
    System Diagram

    Transponder Key Amplifier

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