Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM1000000018H8N
Model Year Start: 2018 Model: Sienna Prod Date Range: [11/2017 -           ]
Title: LIGHTING (EXT): LIGHTING SYSTEM: TERMINALS OF ECU; 2018 - 2020 MY Sienna [11/2017 -        ]

TERMINALS OF ECU

1. CHECK INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY AND MAIN BODY ECU

(a) Disconnect the 2A, 2D, 2F, 2K, D13 and D14 instrument panel junction block assembly and main body ECU connectors.

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

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

2A-17 - Body ground

L - Body ground

ACC power supply

Ignition switch ACC

11 to 14 V

Ignition switch off

Below 1 V

2A-16 - Body ground

Y - Body ground

IG power supply

Ignition switch ON

11 to 14 V

Ignition switch off

Below 1 V

2F-40 (BECU) - Body ground

W - Body ground

Battery power supply

Always

11 to 14 V

2K-1 - Body ground

W - Body ground

Battery power supply

Always

11 to 14 V

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

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

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

2D-28 (GND1) - Body ground

W-B - Body ground

Ground

Always

Below 1 Ω

D14-3 (GND2) - Body ground

W-B - Body ground

Ground

Always

Below 1 Ω

D13-22 (CLTE) - Body ground

LG - Body ground

Automatic light control ground

Always

Below 1 Ω

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

(d) Reconnect the 2A, 2D, 2F, 2K, D13 and D14 instrument panel junction block assembly and main body ECU connectors.

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

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

D13-15 (DRL)*1 - Body ground

GR - Body ground

Daytime running light system drive output

Daytime running light system operates

Below 1 V

Daytime running light system does not operate

11 to 14 V

2F-35 (DIM) - Body ground

GR - Body ground

High beam headlights drive output

Dimmer switch in high or high flash position

Below 1 V

Dimmer switch in low position

11 to 14 V

2F-22 (PKB) - Body ground

R - Body ground

Parking brake switch input

Parking brake switch on

Below 1 V

Parking brake switch off

11 to 14 V

2F-25 (HRLY) - Body ground

LG - Body ground

Headlight relay drive output

Light control switch in head position

Below 1 V

Light control switch not in head position

11 to 14 V

2H-34 (FLCY) - Body ground

P - Body ground

Front door courtesy light switch LH input

Front door LH open

Below 1 V

Front door LH closed

11 to 14 V

2H-36 (FRCY) - Body ground

GR - Body ground

Front door courtesy light switch RH input

Front door RH open

Below 1 V

Front door RH closed

11 to 14 V

2H-33 (LSWL) - Body ground

LG - Body ground

Rear door unlock detection switch LH input

Rear door LH locked

Pulse generation

Rear door LH unlocked

Below 1 V

D12-3 (LCTY) - Body ground

GR - Body ground

Rear door courtesy light switch LH input

Rear door LH open

Below 1 V

Rear door LH closed

Pulse generation

D13-5 (HU) - Body ground

P - Body ground

Dimmer switch high position signal input

Dimmer switch in high or high flash position

Below 1 V

Dimmer switch in low position

Pulse generation

D13-6 (RCTY) - Body ground

L - Body ground

Rear door courtesy light switch RH input

Rear door RH open

Below 1 V

Rear door RH closed

Pulse generation

D13-7 (LSFL) - Body ground

V - Body ground

Front door unlock detection switch LH input

Front door LH locked

Pulse generation

Front door LH unlocked

Below 1 V

D13-8 (HF) - Body ground

SB - Body ground

Dimmer switch high flash position signal input

Dimmer switch in high flash position

Below 1 V

Dimmer switch not in high flash position

Pulse generation

D13-18 (LSFR) - Body ground

Y - Body ground

Front door unlock detection RH switch input

Front door RH locked

Pulse generation

Front door RH unlocked

Below 1 V

D13-19 (BCTY) - Body ground

GR - Body ground

Back door courtesy light switch input

Back door open

Below 1 V

Back door closed

Pulse generation

D13-20 (CLTB) - Body ground

R - Body ground

Automatic light control sensor power supply output

Ignition switch off

Below 1 V

Ignition switch ON and light control switch in AUTO position

11 to 14 V

D13-21 (CLTS) - Body ground

G - Body ground

Automatic light control sensor signal input

Ignition switch off

Below 1 V

Automatic light control system operates

Pulse generation

(See waveform 1)

D13-27 (FFOG) - Body ground

R - Body ground

Front fog light switch input

Front fog light switch on

Below 1 V

Front fog light switch off

Pulse generation

D13-28 (A) - Body ground

V - Body ground

Light control switch AUTO*3 or DRL*4 position signal input

Light control switch in AUTO*3 or DRL*4 position

Below 1 V

Light control switch not in AUTO*3 or DRL*4 position

Pulse generation

D13-29 (HEAD) - Body ground

R - Body ground

Light control switch head position input

Light control switch in head position

Below 1 V

Light control switch not in head position and ignition switch off

Pulse generation

Light control switch not in head position and ignition switch ON

11 to 14 V

D13-30 (TAIL) - Body ground

Y - Body ground

Light control switch tail position signal input

Light control switch in tail or head position

Below 1 V

Light control switch in neither tail nor head position, and ignition switch off

Pulse generation

Light control switch in neither tail nor head position, and ignition switch ON

11 to 14 V

D14-2 (LSWR) - Body ground

L - Body ground

Rear door unlock detection switch RH input

Rear door RH locked

Pulse generation

Rear door RH unlocked

Below 1 V

D14-20 (SBEM) - Body ground*2*6

GR - Body ground

High beam headlights drive output

Dimmer switch in high or high flash position

Below 1 V

Dimmer switch in low position

11 to 14 V
  • *1: w/ Daytime Running Light System
  • *2: w/o Daytime Running Light System
  • *3: w/ Automatic Light Control System
  • *4: w/ DRL switch
  • *5: for Halogen Headlight
  • *6: for HID Headlight

If the result is not as specified, the main body ECU or instrument panel junction block assembly may have a malfunction.

(1) Waveform 1

Item

Content

Tool setting

5 V/DIV., 5 ms./DIV.

HINT:

If the ambient light becomes brighter, width A becomes narrower.

2. CHECK COMBINATION METER ASSEMBLY

(a) Disconnect the D146 combination meter assembly connector.

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

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

D146-1 (B) - Body ground

W - Body ground

Battery power supply

Always

11 to 14 V

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

(c) Reconnect the D146 combination meter assembly connector.

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

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

D146-5 (HAZ) - Body ground

B - Body ground

Hazard warning signal switch input

Hazard warning signal switch off

11 to 14 V

Hazard warning signal switch on

Below 1 V

D146-9 (ER) - Body ground

GR - Body ground

Turn signal switch right signal input

Ignition switch ON, turn signal switch in neutral position

11 to 14 V

Ignition switch ON, turn signal switch in right turn position

Below 1 V

D146-10 (EL) - Body ground

V - Body ground

Turn signal switch left signal input

Ignition switch ON, turn signal switch in neutral position

11 to 14 V

Ignition switch ON, turn signal switch in left turn position

Below 1 V

If the result is not as specified, the combination meter assembly may be malfunctioning.