Terminals Of Ecu

ARRANGEMENT OF MAYDAY ECU TERMINAL

MAYDAY ECU TERMINAL REFERENCE

Symbols (Terminal No.)	Wiring Color	Terminal Description
+B (U45-1)	GR	Vehicle battery power supply
SPO+ (U45-2)	LG	Audio speaker output +
SPO- (U45-3)	L	Audio speaker output -
MCVD (U45-7)	O	Microphone power supply
MCI+ (U45-8)	G	Microphone input signal +
MCI- (U45-9)	R	Microphone input signal -
SPI+ (U45-10)	LG	Sound signal
SPI- (U45-11)	L	Sound signal
E (U45-12)	W-B	Ground
IG2 (U45-13)	B	IG power supply
ACC (U45-14)	V	ACC power supply
GSW (U45-16)	Y	Airbag signal
MCO+ (U45-17)	B	Microphone output
MCO- (U45-18)	W	Audio ground
SG (U45-19)	Shielded	Shield ground
HFOF (U45-21)	P	Phone mute
MUTE (U45-22)	W	Radio mute
MPX1 (U45-23)	GR	MPX line
BBI+ (U46-2)	L	Mayday battery input
SLED (U46-3)	GR	Mayday switch backup light
IND1 (U46-4)	G	Red LED output
SIG1 (U46-5)	LG	Mayday switch input
BBI- (U46-9)	Y	Mayday battery input
IND2 (U46-11)	W	Green LED output
SIG- (U46-12)	B	Mayday switch ground
SIG2 (U46-13)	SB	Mayday switch input
WFSE (U46-14)	P	DLC3 line
SIL (U46-15)	R	DLC3 line

CHECK MAYDAY ECU

Fig 1: Identifying Mayday ECU Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Measure the resistance and voltage of the wire harness side connectors.

TERMINAL DESCRIPTION SPECIFIED CONDITION CHART

Symbols (Terminal No.)	Wiring Color	Terminal Description	Condition	Specified Condition
E (U45-12) - Body ground	W-B - Body ground	Ground	Always	Below 1 Ω
+B (U45-1) - Body ground	GR - Body ground	Vehicle battery power supply	Always	10 to 14 V
ACC (U45-14) - Body ground	V - Body ground	ACC power supply	Engine switch on (ACC)	10 to 14 V
IG2 (U45-13) - Body ground	B - Body ground	IG power supply	Engine switch on (IG)	10 to 14 V

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