Toyota Avalon Service & Repair Manual: Terminals Of Ecu

TERMINALS OF ECU

CHECK DRIVING SUPPORT ECU ASSEMBLY

NOTICE:

Do not apply excessive force to the connector. If a force of 10 kg or more is applied, the connector may be broken.

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

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

G39-23 (SPSW) - G39-28 (GND)

R - W-B

Steering pad switch assembly signal (distance control signal)

Engine switch on (IG), steering pad switch assembly (vehicle-to-vehicle distance control switch) off

4.75 to 5.25 V

Engine switch on (IG), steering pad switch assembly (vehicle-to-vehicle distance control switch) on

Below 1 V

G39-28 (GND) - Body ground

W-B - Body ground

Ground

Always

Below 1 Ω

G39-7 (B) - G39-28 (GND)

B - W-B

Power source

Engine switch on (IG)

11 to 14 V

Engine switch off

Below 1 V

(b) Check for pulses according to the value(s) in the table below.

HINT:

If the waveform is not similar to that shown in the illustration, a malfunction of a CAN bus line, terminating resistor, or the driving support ECU assembly is suspected.

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

G39-8 (CA1P) - G39-28 (GND)

G - W-B

CAN communication signal

Engine switch on (IG)

Pulse generation

(See waveform 1)

G39-9 (CA1N) - G39-28 (GND)

W - W-B

Pulse generation

(See waveform 2)

G39-10 (CA2H) - G39-28 (GND)

R - W-B

Pulse generation

(See waveform 1)

G39-11 (CA2L) - G39-28 (GND)

W - W-B

Pulse generation

(See waveform 2)

(1) WAVEFORM 1

Item

Content

Tester Connection

  • Between G39-8 (CA1P) and G39-28 (GND)
  • Between G39-10 (CA2H) and G39-28 (GND)

Tool Setting

1 V/DIV., 10 μsec./DIV.

Condition

Engine switch on (IG)

HINT:

The waveform varies depending on the CAN communication signal.

(2) WAVEFORM 2

Item

Content

Tester Connection

  • Between G39-9 (CA1N) and G39-28 (GND)
  • Between G39-11 (CA2L) and G39-28 (GND)

Tool Setting

1 V/DIV., 10 μsec./DIV.

Condition

Engine switch on (IG)

HINT:

The waveform varies depending on the CAN communication signal.

CHECK ECM

HINT:

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

Terminal No. (Symbols)

Wiring Color

Terminal Description

Condition

Specified Condition

A18-27 (STP) - C56-53 (E1)

SB - W-B

Stop light switch signal

Brake pedal depressed

7.5 to 14 V

Brake pedal released

Below 1.5 V

A18-41 (CCS) - C56-53 (E1)

R - W-B

Steering pad switch circuit

Cruise control switch not pushed

1 MΩ or higher

Cruise control main switch pushed

Below 2.5 Ω

CANCEL switch pushed

228 to 252 Ω

+RES switch pushed

599 to 661 Ω

-SET switch pushed

1463 to 1617 Ω

A18-42 (ST1-) - C56-53 (E1)

LG - W-B

Stop light switch signal

Engine switch on (IG), brake pedal depressed

0 to 1.5 V

Engine switch on (IG), brake pedal released

7.5 to 14 V

CHECK MILLIMETER WAVE RADAR SENSOR ASSEMBLY

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

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

A25-1 (SGND) - Body ground

W-B - Body ground

Ground

Always

Below 1 Ω

A25-8 (IGB) - A25-1 (SGND)

R - W-B

Power source

Engine switch on (IG)

11 to 14 V

(b) Check for pulses according to the value(s) in the table below.

HINT:

If the waveform is not similar to that shown in the illustration, a malfunction of a CAN bus line, terminating resistor, or the millimeter wave radar sensor assembly is suspected.

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

A25-3 (CA2H) - A25-1 (SGND)

R - W-B

CAN communication signal

Engine switch on (IG)

Pulse generation

(See waveform 1)

A25-2 (CA2L) - A25-1 (SGND)

W - W-B

Pulse generation

(See waveform 2)

A25-5 (CA1P) - A25-1 (SGND)

G - W-B

Pulse generation

(See waveform 1)

A25-6 (CA1N) - A25-1 (SGND)

W - W-B

Pulse generation

(See waveform 2)

(1) WAVEFORM 1

Item

Content

Tester Connection

  • Between A25-3 (CA2H) and A25-1 (SGND)
  • Between A25-5 (CA1P) and A25-1 (SGND)

Tool Setting

1 V/DIV., 10 μsec./DIV.

Condition

Engine switch on (IG)

HINT:

The waveform varies depending on the CAN communication signal.

(2) WAVEFORM 2

Item

Content

Tester Connection

  • Between A25-2 (CA2L) and A25-1 (SGND)
  • Between A25-6 (CA1N) and A25-1 (SGND)

Tool Setting

1 V/DIV., 10 μsec./DIV.

Condition

Engine switch on (IG)

HINT:

The waveform varies depending on the CAN communication signal.

    System Diagram

    Lost Communication with ECM / PCM "A" (U0100,U0125,U0126,U0129)

    See More:

    Toyota Avalon Service & Repair Manual > Can Communication System(for Hv Model): Open in Bus 4 Main Bus Line
    DESCRIPTION There may be an open circuit in one of the CAN main bus lines when the resistance between terminals 22 (CA2H) and 7 (CA2L) of the central gateway ECU (network gateway ECU) is 70 Ω or higher. Symptom Trouble Area Resistance between terminals 22 (CA2H) and 7 (CA2L) of the central gateway ...

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