Toyota Tacoma 2015-2018 Service Manual: Terminals Of Ecu

Toyota Tacoma 2015-2018 Service Manual / Lighting / Lighting System / Terminals Of Ecu

TERMINALS OF ECU

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

Text in Illustration

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.

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
MB-30 (ACC) - Body ground	-	ACC power supply	Ignition switch off	Below 1 V
MB-32 (IG) - Body ground	-	IG power supply	Ignition switch ON	11 to 14 V
MB-32 (IG) - Body ground	-	IG power supply	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
M6-1 (DIM) - Body ground	Y - Body ground	Dimmer relay output	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
1F-28 - Body ground	W - Body ground	Headlight relay drive output	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
1F-30 - Body ground*1	R - Body ground	Daytime running light system drive output	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
M6-24 (HU) - Body ground	BE - Body ground	Dimmer switch high position signal input	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
M6-10 (HF) - Body ground	SB - Body ground	Dimmer switch high flash position signal input	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
M6-17 (AHBI) - Body ground*5	R - Body ground	Auto high beam main switch signal input	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
M6-22 (TAIL) - Body ground	G - Body ground	Light control switch tail position signal input	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
M6-12 (HEAD) - Body ground	Y - Body ground	Light control switch head position input	Ignition switch off, light control switch not in head position	11 to 14 V or pulse generation
M6-8 (A) - Body ground2, 4	W - Body ground	Light control switch AUTO position signal input	Light control switch in AUTO position	Below 1 V
M6-8 (A) - Body ground2, 4	W - Body ground	Light control switch AUTO position signal input	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
M6-26 (FFOG) - Body ground*3	L - Body ground	Fog light switch front position input	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
M6-19 (CLTB)4 - M6-21 (CLTE)4	P - R	Automatic light control sensor power supply output	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
M6-20 (CLTS)*4 - Body ground	GR - Body ground	Automatic light control sensor signal input	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
1F-27 - Body ground*3	BE - Body ground	Front fog light drive output	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
1H-36 - Body ground	P - Body ground	Rear door courtesy light switch LH input	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
1D-30 - Body ground	V - Body ground	Rear door courtesy light switch RH input	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
M6-6 (FLCY) - Body ground	Y - Body ground	Front door courtesy light switch LH input	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
M6-27 (FRCY) - Body ground	LG - Body ground	Front door courtesy light switch RH input	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
1H-27 - Body ground	L - Body ground	Rear door unlock detection switch LH input	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
1A-41 - Body ground	Y - Body ground	Rear door unlock detection switch RH input	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
1D-11 - Body ground	P - Body ground	Front door unlock detection switch LH input	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
1D-24 - Body ground	GR - Body ground	Front door unlock detection switch RH input	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.

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