SFI SYSTEM TERMINALS OF ECM

Tech Tips

The standard normal voltage between each pair of the ECM terminals is shown in the table below. The appropriate conditions for checking each pair of the terminals are also indicated. The result of checks should be compared with the standard normal voltage for that pair of the terminals, and displayed in the "Specified Condition" column. The illustration above can be used as a reference to identify the ECM terminal locations.

Terminal No. (Symbol)	Wiring Color	Terminal Description	Condition	Specified Condition
A18-20 (BATT) - B8-105 (E1)	B - BR	Battery (for measuring battery voltage and for ECM memory)	Always	11 to 14 V
A18-2 (+B) - B8-105 (E1)	W - BR	Power source of ECM	Ignition switch ON	11 to 14 V
A18-1 (+B2) - B8-105 (E1)	L - BR	Power source of ECM	Ignition switch ON	11 to 14 V
A18-3 (+BM) - B8-105 (E1)	R-W - BR	Power source of throttle actuator	Always	11 to 14 V
B8-109 (IGT1) - B8-105 (E1)	W - BR	Ignition coil (ignition signal)	Idling	Pulse generation (see waveform 1)
B8-108 (IGT2) - B8-105 (E1)	L - BR
B8-107 (IGT3) - B8-105 (E1)	GR - BR
B8-82 (IGF1) - B8-105 (E1)	Y - BR	Ignition coil (ignition confirmation signal)	Ignition switch ON	4.5 to 5.5 V
B8-82 (IGF1) - B8-105 (E1)	Y - BR	Ignition coil (ignition confirmation signal)	Idling	Pulse generation (see waveform 1)
B8-93 (NE+) - B8-117 (NE-)	G - P-L	Crankshaft position sensor	Idle after engine warmed-up	Pulse generation (see waveform 2)
B8-94 (G2+) - B8-117 (NE-)	B - P-L	Camshaft position sensor	Idle after engine warmed-up	Pulse generation (see waveform 2)
B8-86 (#10) - B8-46 (E01)	LG - W-B	Fuel injector	Ignition switch ON	11 to 14 V
B8-85 (#20) - B8-46 (E01)	P - W-B		Ignition switch ON	11 to 14 V
B8-84 (#30) - B8-46 (E01)	V - W-B		Idling	Pulse generation (see waveform 3)
B8-104 (HA1A) - B8-41 (E04)	B - W-B	Air fuel ratio sensor (sensor 1) heater	Ignition switch ON	11 to 14 V
B8-104 (HA1A) - B8-41 (E04)	B - W-B	Air fuel ratio sensor (sensor 1) heater	Idle after engine warmed-up	Pulse generation (see waveform 4)
B8-103 (A1A+) - B8-105 (E1)	L - BR	Air fuel ratio sensor (sensor 1)	Idling	Below 3.3 V^*1
B8-126 (A1A-) - B8-105 (E1)	G - BR	Air fuel ratio sensor (sensor 1)	Idling	Below 2.9 V^*1
B8-63 (HT1B) - B8-81 (E03)	B - W-B	Heated oxygen sensor (sensor 2) heater	Ignition switch ON	11 to 14 V
B8-63 (HT1B) - B8-81 (E03)	B - W-B	Heated oxygen sensor (sensor 2) heater	Idling	Below 3.0 V
B8-80 (OX1B) - B8-79 (O1B-)	G - R	Heated oxygen sensor (sensor 2)	Engine speed maintained at 2500 rpm for 2 minutes after warming up sensor	Pulse generation (see waveform 5)
B8-110 (KNK1) - B8-111 (EKNK)	B - W	Knock sensor	Engine speed maintained at 4000 after warming up engine	Pulse generation (see waveform 6)
A18-38 (SPD) - B8-105 (E1)	R-B - BR	Speed signal from combination meter	Rotate driving wheel slowly	Pulse generation (see waveform 7)
B8-66 (THW) - B8-65 (ETHW)	LG - P	Engine coolant temperature sensor	Idling, Engine coolant temperature 80°C (176°F)	0.2 to 1.0 V
B8-87 (THA) - B8-120 (E2)	R-Y - G-R	Intake air temperature sensor (built into manifold absolute pressure sensor)	Idling, Intake air temperature 20°C (68°F)	1.5 to 3.0 V
B8-114 (PIM) - B8-120 (E2)	L-Y - G-R	Manifold absolute pressure sensor	Idling	1.2 to 2.0 V
A18-24 (W) - B8-105 (E1)	P-B - BR	MIL	Ignition switch ON (MIL goes on)	Below 3.0 V
A18-24 (W) - B8-105 (E1)	P-B - BR	MIL	Idling	11 to 14 V
A18-48 (STA) - B8-105 (E1)	W-R - BR	Starter signal	Ignition switch ON	Below 1.5 V
A18-48 (STA) - B8-105 (E1)	W-R - BR	Starter signal	Cranking	11 to 14 V
A18-25 (NSW) - B8-105 (E1)	GR - BR	Clutch pedal switch signal2 Park/Neutral position switch signal3	Ignition switch ON, Clutch pedal fully depressed*2	Below 1.5 V
			Ignition switch ON, Clutch pedal released*2	11 to 14 V
			Ignition switch ON, shift lever in P, N*3	Below 1.5 V
			Ignition switch ON, shift lever not in P, N*3	11 to 14 V
			Cranking	11 to 14 V
B8-113 (VTA1) - B8-90 (ETA)	W - B	Throttle position sensor (for engine control)	Ignition switch ON, Throttle valve fully closed	0.5 to 1.1 V
B8-113 (VTA1) - B8-90 (ETA)	W - B	Throttle position sensor (for engine control)	Ignition switch ON, Throttle valve fully open	3.2 to 4.8 V
B8-112 (VTA2) - B8-90 (ETA)	GR - B	Throttle position sensor (for sensor malfunction detection)	Ignition switch ON, Accelerator pedal released	2.1 to 3.1 V
B8-112 (VTA2) - B8-90 (ETA)	GR - B	Throttle position sensor (for sensor malfunction detection)	Ignition switch ON, Accelerator pedal depressed	4.5 to 5.5 V
B8-89 (VCTA) - B8-90 (ETA)	Y - B	Power source of sensor (specific voltage)	Ignition switch ON	4.5 to 5.5 V
A18-57 (VCPA) - A18-59 (EPA)	G-R - LG	Power source of accelerator pedal position sensor (for VPA)	Ignition switch ON	4.5 to 5.5 V
A18-55 (VPA) - A18-59 (EPA)	LG-R - LG	Accelerator pedal position sensor (for engine control)	Ignition switch ON, Accelerator pedal released	0.5 to 1.1 V
A18-55 (VPA) - A18-59 (EPA)	LG-R - LG	Accelerator pedal position sensor (for engine control)	Ignition switch ON, Accelerator pedal fully depressed	2.5 to 4.5 V
A18-56 (VPA2) - A18-60 (EPA2)	V-Y - V	Accelerator pedal position sensor (for sensor malfunctioning detection)	Ignition switch ON, Accelerator pedal released	1.2 to 2.0 V
A18-56 (VPA2) - A18-60 (EPA2)	V-Y - V		Ignition switch ON, Accelerator pedal fully depressed	3.4 to 5.5 V
A18-58 (VCP2) - A18-60 (EPA2)	L-W - V	Power source of accelerator pedal position sensor (for VPA2)	Ignition switch ON	4.5 to 5.5 V
B8-43 (M+) - B8-44 (ME01)	G - BR	Throttle actuator	Idling with warm engine	Pulse generation (see waveform 8)
B8-42 (M-) - B8-44 (ME01)	R - BR	Throttle actuator	Idling with warm engine	Pulse generation (see waveform 9)
A18-36 (STP) - B8-105 (E1)	Y - BR	Stop light switch	Brake pedal depressed	11 to 14 V
A18-36 (STP) - B8-105 (E1)	Y - BR	Stop light switch	Brake pedal released	Below 1.5 V
A18-35 (ST1-) - B8-105 (E1)	R-L - BR	Stop light switch	Ignition switch ON, Brake pedal depressed	Below 1.5 V
A18-35 (ST1-) - B8-105 (E1)	R-L - BR	Stop light switch	Ignition switch ON, Brake pedal released	11 to 14 V
B8-62 (PRG) - B8-105 (E1)	L-W - BR	Purge VSV	Ignition switch ON	11 to 14 V
B8-62 (PRG) - B8-105 (E1)	L-W - BR	Purge VSV	Idling, under purge control	Pulse generation (see waveform 10)
A18-19 (FC) - B8-105 (E1)	P - BR	Fuel pump control	Ignition switch ON	11 to 14 V
A18-19 (FC) - B8-105 (E1)	P - BR	Fuel pump control	Idling	Below 1.5 V
A18-15 (TACH) - B8-105 (E1)	R-Y - BR	Engine speed	Idling	Pulse generation (see waveform 11)
A18-40 (TC) - B8-105 (E1)	R-G - BR	Terminal TC of DLC3	Ignition switch ON	11 to 14 V
B8-97 (OC1+) - B8-96 (OC1-)	G - R-W	Camshaft timing oil control valve (OCV)	Idling	Pulse generation (see waveform 12)
B8-38 (ACM) - B8-105 (E1)	Y - BR	VSV (for engine mounting)	Idling	Below 1.5 V
A18-8 (CANH) - B8-105 (E1)	L - BR	CAN communication line	Ignition switch ON	Pulse generation (see waveform 13)
A18-9 (CANL) - B8-105 (E1)	W - BR	CAN communication line	Ignition switch ON	Pulse generation (see waveform 14)
B8-51 (EGR1) - A18-105 (E1)	R-B - BR	EGR valve	Racing engine	Pulse generation (see waveform 15)
B8-50 (EGR2) - A18-105 (E1)	B-Y - BR
B8-49 (EGR3) - A18-105 (E1)	W-G - BR
B8-48 (EGR4) - A18-105 (E1)	B-R - BR
A18-21 (FANL) - B8-105 (E1)	LG - BR	NO. 1 FAN relay	Ignition switch ON	11 to 14 V
A18-21 (FANL) - B8-105 (E1)	LG - BR	NO. 1 FAN relay	Idling with A/C ON or High engine coolant temperature	Below 1.5 V
A18-22 (FANH) - B8-105 (E1)	G-R - BR	NO. 2 FAN relay	Idling with high engine coolant temperature	Below 1.5 V
A18-27 (IGSW) - B8-105 (E1)	G-W - BR	Ignition switch	Ignition switch ON	11 to 14 V
A18-44 (MREL) - B8-105 (E1)	L-Y - BR	EFI relay	Ignition switch ON	11 to 14 V
B8-67 (VC) - B8-105 (E1)	LG-R - BR	Power source of manifold absolute pressure sensor	Ignition switch ON	4.5 to 5.5 V
A18-31 (ELS) - B8-105 (E1)	L-R - BR	Electric load	Tail light switch on	7.5 to 14 V
A18-31 (ELS) - B8-105 (E1)	L-R - BR	Electric load	Tail light switch off	Below 1.5 V
A18-50 (ELS2) - B8-105 (E1)	W-L - BR	Electric load	Defogger switch on	7.5 to 14 V
A18-50 (ELS2) - B8-105 (E1)	W-L - BR	Electric load	Defogger switch off	Below 1.5 V

Tech Tips

^*1: The ECM terminal voltage is constant regardless of the output voltage from the sensor.

^*2: for Manual transaxle.

^*3: for CVT.

WAVEFORM 1

Igniter IGT Signal (from ECM to Igniter)
ECM Terminal Name	Between IGT (1 to 3) and E1 Between IGF1 and E1
Tester Range	2 v/DIV, 20 ms/DIV
Condition	Idling

Tech Tips

The wavelength becomes shorter as the engine rpm increases.

WAVEFORM 2

Crankshaft Position Sensor and Camshaft Position Sensor
ECM Terminal Name	CH1: Between G2+ and NE- CH2: Between NE+ and NE-
Tester Range	5 v/DIV, 20 ms/DIV
Condition	Idle after engine warmed-up

Tech Tips

The wavelength becomes shorter as the engine rpm increases.

WAVEFORM 3

No. 1 (to No. 3) Injector Signal
ECM Terminal Name	Between #10 (to #30) and E01
Tester Range	20 v/DIV, 20 ms/DIV
Condition	Idling

Tech Tips

The wavelength becomes shorter as the engine rpm increases.

WAVEFORM 4

Air Fuel Ratio Sensor (Sensor 1) Heater
ECM Terminal Name	Between HA1A and E04
Tester Range	5 v/DIV, 10 ms/DIV
Condition	Idle after engine warmed-up

Tech Tips

The wavelength varies in accordance with the engine operating condition.

WAVEFORM 5

Heated Oxygen Sensor (Sensor 2)
ECM Terminal Name	Between OX1B and O1B-
Tester Range	0.2 v/DIV, 200 ms/DIV
Condition	Maintain engine speed at 2500 rpm for 2 minutes after warming up sensor

Tech Tips

In the Data List, the item O2S B1S2 show the values input to the ECM from the heated oxygen sensor.

WAVEFORM 6

Knock Sensor
ECM Terminal Name	Between KNK1 and EKNK
Tester Range	500 mv/DIV, 1 ms/DIV
Condition	Maintain engine speed at 4000 rpm after engine warmed-up

Tech Tips

The wavelength becomes shorter as the engine rpm increases.
The waveforms and amplitudes displayed differ slightly depending on the vehicle condition.

WAVEFORM 7

Vehicle Speed Signal
ECM Terminal Name	Between SPD and E1
Tester Range	5 v/DIV, 20 ms/DIV
Condition	Rotate driving wheel slowly

Tech Tips

The wavelength becomes shorter as the vehicle speed increases.

WAVEFORM 8

Throttle Actuator Positive Terminal
ECM Terminal Name	Between M+ and ME01
Tester Range	5 v/DIV, 1 ms/DIV
Condition	Idle after engine warmed-up

Tech Tips

The duty ratio varies depending on the throttle actuator operation.

WAVEFORM 9

Throttle Actuator Negative Terminal
ECM Terminal Name	Between M- and ME01
Tester Range	5 v/DIV, 1 ms/DIV
Condition	Idle after engine warmed-up

Tech Tips

The duty ratio varies depending on the throttle actuator operation.

WAVEFORM 10

Purge VSV
ECM Terminal Name	Between PRG and E1
Tester Range	10 v/DIV, 20 ms/DIV
Condition	Idling, under purge control

Tech Tips

If the waveform is not similar to the illustration, check the waveform again after idling for 10 minutes or more.

WAVEFORM 11

Engine Speed Signal
ECM Terminal Name	Between TACH and E1
Tester Range	5 v/DIV, 10 ms/DIV
Condition	Idling

Tech Tips

The wavelength becomes shorter as the engine rpm increases.

WAVEFORM 12

Camshaft Timing Oil Control Valve (OCV)
ECM Terminal Name	Between OC1+ and OC1-
Tester Range	5 v/DIV, 1 ms/DIV
Condition	Idling

WAVEFORM 13

CAN Communication Signal (Reference)
ECM Terminal Name	Between CANH and E1
Tester Range	1 v/DIV, 10 μs/DIV
Condition	Engine stopped and ignition switch ON

Tech Tips

The waveform varies depending on the CAN communication signal.

WAVEFORM 14

CAN Communication Signal (Reference)
ECM Terminal Name	Between CANL and E1
Tester Range	1 v/DIV, 10 μs/DIV
Condition	Engine stopped and ignition switch ON

Tech Tips

The waveform varies depending on the CAN communication signal.

WAVEFORM 15

EGR Valve
ECM Terminal Name	EGR1, EGR2, EGR3, EGR4 and E1
Tester Range	20 v/DIV, 50 ms/DIV
Condition	Repeated quick engine rpm acceleration