Home › Vehicle Exterior › Door/Hatch › POWER BACK DOOR SYSTEM
Last Modified: 11-27-2007 1.6 U
Service Category: Vehicle Exterior Section: Door/Hatch
Model Year: 2008 Model: LX570 Doc ID: RM000003EBT000X
Title: DOOR / HATCH: POWER BACK DOOR SYSTEM: TERMINALS OF ECU (2008 LX570)

TERMINALS OF ECU

1. CHECK POWER BACK DOOR UNIT



(a) Disconnect the L36 unit connector.

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

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

L36-12 (B) - Body ground

B - Body ground

B power supply

Always

11 to 14 V

L36-8 (IG) - Body ground

G - Body ground

IG power supply

Engine switch on (IG)

11 to 14 V

L36-8 (IG) - Body ground

G - Body ground

IG power supply

Engine switch off

Below 1 V

L36-10 (ECUB) - Body ground

R - Body ground

ECUB power supply

Always

11 to 14 V

L36-15 (OSL) - L36-14 (OSE)

G - BR

Power back door sensor LH circuit

Power back door sensor LH not pressed

Approximately 1 kΩ

L36-15 (OSL) - L36-14 (OSE)

G - BR

Power back door sensor LH circuit

Power back door sensor LH pressed

Below 100 Ω

L36-13 (OSR) - L36-14 (OSE)

Y - BR

Power back door sensor RH circuit

Power back door sensor RH not pressed

Approximately 1 kΩ

L36-13 (OSR) - L36-14 (OSE)

Y - BR

Power back door sensor RH circuit

Power back door sensor RH pressed

Below 100 Ω

L36-11 (GND) - Body ground

W-B - Body ground

Body ground

Always

Below 1 Ω

L36-17 (MSW) - Body ground

G - Body ground

Power back door main switch signal circuit

Power back door main switch not pushed (on)

Below 1 Ω

L36-17 (MSW) - Body ground

G - Body ground

Power back door main switch signal circuit

Power back door main switch pushed (off)

10 kΩ or higher

L36-4 (DS1) - Body ground

R - Body ground

Back door control switch signal circuit

Back door control switch on

Below 1 Ω

L36-4 (DS1) - Body ground

R - Body ground

Back door control switch signal circuit

Back door control switch off

10 kΩ or higher

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

(c) Reconnect the L36 unit connector.

(d) Measure the voltage according to the value(s) in the table below.

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

L36-26 (BZR+) - Body ground

L - Body ground

Power back door warning buzzer signal input

Power back door warning buzzer sounding

Pulse generation

(see waveform 1)

L36-26 (BZR+) - Body ground

L - Body ground

Power back door warning buzzer signal input

Power back door warning buzzer stopped

Below 1 V

L36-2 (DC+) - L36-1 (DC-)

R - B

Power back door lock motor circuit

Power back door lock motor operating

11 to 14 V

L36-2 (DC+) - L36-1 (DC-)

R - B

Power back door lock motor circuit

Power back door lock motor stopped

Below 1 V

L36-17 (MSW) - Body ground

G - Body ground

Power back door main switch signal circuit

Power back door main switch not pushed (on)

Below 1 V

L36-17 (MSW) - Body ground

G - Body ground

Power back door main switch signal circuit

Power back door main switch pushed (off)

Pulse generation

(see waveform 2)

L36-20 (FUL) - Body ground

W - Body ground

Back door courtesy switch signal circuit

Back door opened

Below 1 V

L36-20 (FUL) - Body ground

W - Body ground

Back door courtesy switch signal circuit

Back door closed

Pulse generation

(see waveform 3)

L36-4 (DS1) - Body ground

R - Body ground

Back door control switch signal circuit

Back door control switch on

Below 1 V

L36-4 (DS1) - Body ground

R - Body ground

Back door control switch signal circuit

Back door control switch off

Pulse generation

(see waveform 4)

L36-22 (HAF) - Body ground

G - Body ground

Back door lock half-latch switch signal circuit

Back door opened

Below 1 V

L36-22 (HAF) - Body ground

G - Body ground

Back door lock half-latch switch signal circuit

Back door closed

Pulse generation

(see waveform 5)

L36-24 (POS) - Body ground

B - Body ground

Back door lock position switch signal circuit

Back door closed

Below 1 V

L36-24 (POS) - Body ground

B - Body ground

Back door lock position switch signal circuit

Back door opened

Pulse generation

(see waveform 6)

L36-23 (CYLH) - Body ground

G - Body ground

Lower tail gate courtesy switch LH circuit

Lower tail gate opened

Below 1 V

L36-23 (CYLH) - Body ground

G - Body ground

Lower tail gate courtesy switch LH circuit

Lower tail gate closed

Pulse generation

(see waveform 7)

L36-7 (CYRH) - Body ground

Y - Body ground

Lower tail gate courtesy switch RH circuit

Lower tail gate opened

Below 1 V

L36-7 (CYRH) - Body ground

Y - Body ground

Lower tail gate courtesy switch RH circuit

Lower tail gate closed

Pulse generation

(see waveform 8)

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

(e) Using an oscilloscope, check waveform 1.

Waveform 1 (Reference)

Item

Content

Terminal (Symbol)

L36-26 (BZR+) - Body ground

Tool Setting

5 V/DIV., 1 ms/DIV

Condition

Power back door warning buzzer sounding

(f) Using an oscilloscope, check waveform 2.

Waveform 2 (Reference)

Item

Content

Terminal (Symbol)

L36-17 (MSW) - Body ground

Tool Setting

5 V/DIV., 10 ms/DIV

Condition

Power back door main switch pushed (off)

(g) Using an oscilloscope, check waveform 3.

Waveform 3 (Reference)

Item

Content

Terminal (Symbol)

L36-20 (FUL) - Body ground

Tool Setting

5 V/DIV., 10 ms/DIV

Condition

Back door closed

(h) Using an oscilloscope, check waveform 4.

Waveform 4 (Reference)

Item

Content

Terminal (Symbol)

L36-4 (DS1) - Body ground

Tool Setting

5 V/DIV., 10 ms/DIV

Condition

Back door control switch off

(i) Using an oscilloscope, check waveform 5.

Waveform 5 (Reference)

Item

Content

Terminal (Symbol)

L36-22 (HAF) - Body ground

Tool Setting

5 V/DIV., 10 ms/DIV

Condition

Back door closed

(j) Using an oscilloscope, check waveform 6.

Waveform 6 (Reference)

Item

Content

Terminal (Symbol)

L36-24 (POS) - Body ground

Tool Setting

5 V/DIV., 10 ms/DIV

Condition

Back door opened

(k) Using an oscilloscope, check waveform 7.

Waveform 7 (Reference)

Item

Content

Terminal (Symbol)

L36-23 (CYLH) - Body ground

Tool Setting

5 V/DIV., 10 ms/DIV

Condition

Lower tail gate closed

(l) Using an oscilloscope, check waveform 8.

Waveform 8 (Reference)

Item

Content

Terminal (Symbol)

L36-7 (CYRH) - Body ground

Tool Setting

5 V/DIV., 10 ms/DIV

Condition

Lower tail gate closed

2. CHECK MAIN BODY ECU



(a) Disconnect the 2B, 2D, E2 and E3 ECU connectors.

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

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

2B-20 (BATB) - Body ground

L - Body ground

Battery power supply

Always

11 to 14 V

2D-1 (ACC) - Body ground

B - Body ground

Power supply

Always

11 to 14 V

E2-2 (PBDS) - Body ground

R - Body ground

Power back door control switch circuit

Power back door control switch pushed (on)

Below 1 Ω

E2-2 (PBDS) - Body ground

R - Body ground

Power back door control switch circuit

Power back door control switch not pushed (off)

10 kΩ or higher

2D-62 (GND2) - Body ground

W-B - Body ground

Ground

Always

Below 1 Ω

E3-1 (GND3) - Body ground

BR - Body ground

Ground

Always

Below 1 Ω

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

(c) Reconnect the 2B, 2D, E2 and E3 ECU connectors.

(d) Measure the voltage according to the value(s) in the table below.

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

E2-2 (PBDS) - Body ground

R - Body ground

Power back door control switch circuit

Power back door control switch pushed (on)

Below 1 V

E2-2 (PBDS) - Body ground

R - Body ground

Power back door control switch circuit

Power back door control switch not pushed (off)

Pulse generation

(see waveform)

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

(e) Using an oscilloscope, check waveform.

Waveform (Reference)

Item

Content

Terminal (Symbol)

E2-2 (PBDS) - Body ground

Tool Setting

5 V/DIV., 10 ms/DIV

Condition

Power back door control switch not pushed (off)