Terminals Of Ecu

CHECK COMBINATION METER ASSEMBLY

Fig 1: Identifying Combination Meter Assembly C8 ECU Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Disconnect the C8 meter connector.

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

ECU CONNECTOR TERMINALS REFERENCE CHART

Symbols (Terminal No.)	Wiring Color	Terminal Description	Condition	Specified Condition
IG+ (C8-1) - Body ground	R-Y - Body ground	Ignition switch power supply	Ignition switch ON	10 to 14 V
IG+ (C8-1) - Body ground	R-Y - Body ground	ignition switch power supply	Ignition switch OFF	Below 1 V
B (C8-13) - Body ground	B - Body ground	Battery	Always	10 to 14 V
ES (C8-12) - Body ground	BR - Body ground	Ground	Always	Below 1 Ω

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

Reconnect the C8 meter connector.

Measure the voltage and resistance of the connectors.

ECU CONNECTOR TERMINALS REFERENCE CHART

Symbols (Terminal No.)	Wiring Color	Terminal Description	Condition	Specified Condition
S (C8-5) - ES (C8-12)	B-Y - BR	Tachometer signal (Input)	Engine running	Pulse generation (see e waveform 1)
CHK (C8-6) - Body ground	SB - Body ground	MIL warning signal	Ignition switch ON, MIL OFF	10 to 14 V
CHK (C8-6) - Body ground	SB - Body ground	MIL warning signal	Ignition switch ON, MIL ON	Below 1 V
A/B (C8-8) - ES (C8-12)	R - BR	ODO/TRIP signal	Ignition switch ON, ODO/TRIP not pressed	Below 1 V
A/B (C8-8) - ES (C8-12)	R - BR	ODO/TRIP signal	Ignition switch ON, ODO/TRIP pressed	4.5 to 5.5 V
RSET (C8-9) - ES (C8-12)	P - BR	RESET signal	Ignition switch ON, RESET not pressed	Below 1 V
RSET (C8-9) - ES (C8-12)	P - BR	RESET signal	Ignition switch ON, RESET pressed	4.5 to 5.5 V
PBLT (C8-10) - Body ground	L-R - Body ground	Passenger side seat belt warning signal	Ignition switch ON, passenger side seat belt unfastened (ON)	10 to 14 V
PBLT (C8-10) - Body ground	L-R - Body ground	Passenger side seat belt warning signal	Ignition switch ON, passenger side seat belt fastened (OFF)	Below 1 V
TURN L (C8-15) - Body ground	G-B - Body ground	Turn signal indicator LH signal	Ignition switch ON, turn signal indicator light LH OFF	10 to 14 V
TURN L (C8-15) - Body ground	G-B - Body ground	Turn signal indicator LH signal	Ignition switch ON, turn signal indicator light LH ON	Below 1 V
TURN R (C8-16) - Body ground	G - Body ground	Turn signal indicator RH signal	Ignition switch ON, turn signal indicator light RH OFF	10 to 14 V
TURN R (C8-16) - Body ground	G - Body ground	Turn signal indicator RH signal	Ignition switch ON, turn signal indicator light RH ON	Below 1 V
ILL- (C8-18) - Body ground	W-L - Body ground	Rheostat signal	Ignition switch ON	Pulse generation
SI (C8-20) - Body ground	V - Body ground	Vehicle speed signal (output)	Ignition switch ON, slowly turn rear wheel	Pulse generation (see e waveform 2)
+S (C8-21) - Body ground	W-R - Body ground	Vehicle speed signal (output)	Ignition switch ON, slowly turn rear wheel	Pulse generation (see e waveform 2)
FR (C8-22) - FE (C8-23)	G - W	Fuel sender gauge signal	Ignition switch ON, fuel level F	0.5 V

Using an oscilloscope, check the signal waveform of the meter.

Waveform 1 (Reference)

WAVEFORM REFERENCE CHART

Item	Content
Symbols (Terminal No.)	S (C8-4) - C8-11
Tool Setting	5 V/DIV., 10 msec./DIV.
Vehicle Condition	Driving at approx. 20 km/h (12 mph)

HINT:

As engine speed increases, the wavelength shortens.

Fig 2: Waveform Graph

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Waveform 2 (Reference)

WAVEFORM REFERENCE CHART

Item	Content
Symbols (Terminal No.)	S1 (C8-18) - Body ground +B (C8-21) - Body ground
Tool Setting	5 V/DIV., 10 msec./DIV.
Vehicle Condition	Driving at approx. 20 km/h (12 mph)

HINT:

As engine speed increases, the wavelength shortens.

Fig 3: Waveform Graph

Fig 4: Combination Meter Circuit Diagram (1 Of 2)

Fig 5: Combination Meter Circuit Diagram (2 Of 2)

Table of Terminal Connection

TERMINAL CONNECTION CHART

Terminal No.		Wire Harness Side
C8	1	D-IG fuse
	3	Gateway ECU (MPX+)
	4	Skid control ECU (MPX-)
	5	ECM
	6	ECM
	8	TRIP switch
	9	TRIP switch
	10	Front passenger seat belt warning light
	11	TRIP switch
	12	Body ground
	13	MPX-B2 fuse
	15	Turn signal flasher relay
	16	Turn signal flasher relay
	18	Driver side junction block ECU
	20	Skid control ECU
	21	Multi-display, Navigation ECU*, Stereo component amplifier assembly
	22	Fuel sender gauge assembly (Main)
	23	Fuel sender gauge assembly (Sub)
HINT: *: w/ Navigation System