Toyota Tacoma manuals

Toyota Tacoma (2015-2018) Service Manual: Terminals Of Ecu

TERMINALS OF ECU

1. CHECK MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

Text in Illustration

*1

Main Body ECU (Multiplex Network Body ECU)

-

-

(a) Disconnect the driver side junction block and main body ECU (multiplex network body ECU) connectors.

(b) Measure the voltage on the wire harness side connector according to the value(s) in the table below.

Terminal No. (Symbols)

Wiring Color

Terminal Description

Condition

Specified Condition

MB-31 (BECU) - 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 on the wire harness side connector according to the value(s) in the table below.

Terminal No. (Symbols)

Wiring Color

Terminal Description

Condition

Specified Condition

MB-11 (GND1) - Body ground

-

Ground

Always

Below 1 Ω

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

(d) Reconnect the driver side junction block and main body ECU (multiplex network body ECU) connectors.

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

Terminal No. (Symbols)

Wiring Color

Terminal Description

Condition

Specified Condition

MB-30 (ACC) - Body ground

-

ACC power supply

Ignition switch ACC

11 to 14 V

Ignition switch off

Below 1 V

MB-32 (IG) - Body ground

-

IG power supply

Ignition switch ON

11 to 14 V

Ignition switch off

Below 1 V

M6-1 (DIM) - Body ground

Y - Body ground

Dimmer relay output

Dimmer switch in low position

11 to 14 V

Dimmer switch in high or high flash position

Below 1 V

1F-28 - Body ground

W - 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

1F-30 - Body ground*1

R - Body ground

Daytime running light system drive output

Daytime running light system operating

Below 1 V

Daytime running light system not operating

11 to 14 V

M6-24 (HU) - Body ground

BE - Body ground

Dimmer switch high position signal input

Dimmer switch in high position

Below 1 V

Dimmer switch not in high position

11 to 14 V or pulse generation

M6-10 (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

11 to 14 V or pulse generation

M6-17 (AHBI) - Body ground*5

R - Body ground

Auto high beam main switch signal input

Auto high beam main switch on

Below 1 V

Auto high beam main switch off

11 to 14 V

M6-22 (TAIL) - Body ground

G - Body ground

Light control switch tail position signal input

Light control switch in tail or head position

Below 1 V

Ignition switch off, light control switch not in tail or head position

11 to 14 V or pulse generation

M6-12 (HEAD) - Body ground

Y - Body ground

Light control switch head position input

Light control switch in head position

Below 1 V

Ignition switch off, light control switch not in head position

11 to 14 V or pulse generation

M6-8 (A) - Body ground*2, *4

W - Body ground

Light control switch AUTO position signal input

Light control switch in AUTO position

Below 1 V

Ignition switch off, light control switch not in AUTO position

11 to 14 V or pulse generation

M6-26 (FFOG) - Body ground*3

L - Body ground

Fog light switch front position input

Fog light switch in front position

Below 1 V

Ignition switch off, fog light switch off

11 to 14 V or pulse generation

M6-19 (CLTB)*4 - M6-21 (CLTE)*4

P - R

Automatic light control sensor power supply output

Ignition switch off

Below 1 V

Ignition switch ON

11 to 14 V

M6-20 (CLTS)*4 - Body ground

GR - Body ground

Automatic light control sensor signal input

Ignition switch off

Below 1 V

Ignition switch ON

Communication waveform generation

(See waveform 1)

1F-27 - Body ground*3

BE - Body ground

Front fog light drive output

Light control switch in tail or head position, fog light switch in front position

Below 1 V

Light control switch in tail or head position, fog light switch off

11 to 14 V

1H-36 - Body ground

P - Body ground

Rear door courtesy light switch LH input

Rear door LH open

Below 1 V

Rear door LH closed

Pulse generation

1D-30 - Body ground

V - Body ground

Rear door courtesy light switch RH input

Rear door RH open

Below 1 V

Rear door RH closed

Pulse generation

M6-6 (FLCY) - Body ground

Y - Body ground

Front door courtesy light switch LH input

Front door LH open

Below 1 V

Front door LH closed

pulse generation

M6-27 (FRCY) - Body ground

LG - Body ground

Front door courtesy light switch RH input

Front door RH open

Below 1 V

Front door RH closed

pulse generation

1H-27 - Body ground

L - Body ground

Rear door unlock detection switch LH input

Rear door LH locked

Pulse generation

Rear door LH or rear door RH unlocked

Below 1 V

1A-41 - Body ground

Y - Body ground

Rear door unlock detection switch RH input

Rear door RH locked

Pulse generation

Rear door LH or rear door RH unlocked

Below 1 V

1D-11 - Body ground

P - Body ground

Front door unlock detection switch LH input

Front door LH locked

Pulse generation

Front door LH unlocked

Below 1 V

1D-24 - Body ground

GR - Body ground

Front door unlock detection switch RH input

Front door RH locked

Pulse generation

Front door RH unlocked

Below 1 V

  • *1: LED Type Daytime Running Light and Parking Light
  • *2: w/ Daytime Running Light
  • *3: w/ Fog Light
  • *4: w/ Automatic Light Control
  • *5: w/ Automatic High Beam System

(1) If the result is not as specified, the main body ECU (multiplex network body ECU) or driver side junction block may be malfunctioning.

Waveform 1

Item

Content

Tool setting

2 V/DIV., 10 ms./DIV.

Vehicle condition

Ignition switch ON, automatic light control system operating

HINT:

The communication waveform changes according to the surrounding brightness.

Problem Symptoms Table
PROBLEM SYMPTOMS TABLE HINT: Use the table below to help determine the cause of the problem symptom. The potential causes of the symptoms are listed in order of probability in the &q ...

Light Sensor Circuit Malfunction (B1244)
DESCRIPTION This DTC is output when a failure of the automatic light control sensor circuit is detected. DTC Code DTC Detection Condition Trouble Area ...

Other materials:

Disassembly
DISASSEMBLY CAUTION / NOTICE / HINT HINT: Use the same procedure for both the LH and RH sides. The procedure described below is for the LH side. PROCEDURE 1. REMOVE FOG LIGHT BULB (a) Turn the fog light bulb in the direction indicated by the arrow in the illust ...

Disposal
DISPOSAL CAUTION / NOTICE / HINT HINT: The tire pressure warning valve and transmitter is powered by a lithium battery. When disposing of the tire pressure warning valve and transmitter, remove the battery and dispose of it correctly. PROCEDURE 1. DISPOSE OF TIRE PRESSURE WARNING VALVE AND ...

Stop Light Relay Circuit (C1A4B)
DESCRIPTION The skid control ECU (master cylinder solenoid)*1 or skid control ECU (brake actuator assembly)*2 sends a stop light operation request signal to the stop light relay (stop light switch assembly). If the skid control ECU (master cylinder solenoid)*1 or skid control ECU (brake actua ...

© 2011-2025 Copyright www.ttguide.net