SFI SYSTEM TERMINALS OF ECM

A003S98E13

Tech Tips

The standard normal voltage between each pair of 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 terminals, 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
A50-20 (BATT) - B31-104 (E1) R - BR Battery (for measuring battery voltage and for ECM memory) Always 11 to 14 V
A50-2 (+B) - B31-104 (E1) B - BR Power source of ECM Power switch on (IG) 11 to 14 V
A50-1 (+B2) - B31-104 (E1) B - BR Power source of ECM Power switch on (IG) 11 to 14 V
A50-3 (+BM) - B31-104 (E1) GR - BR Power source of throttle actuator Always 11 to 14 V
B31-108 (IGT1) - B31-104 (E1) GR - BR

Ignition coil assembly

(ignition signal)

 Idling

Pulse generation

(see waveform 1)
B31-107 (IGT2) - B31-104 (E1) W - BR
B31-106 (IGT3) - B31-104 (E1) G - BR
B31-105 (IGT4) - B31-104 (E1) Y - BR
B31-23 (IGF1) - B31-104 (E1) L - BR

Ignition coil assembly

(ignition confirmation signal)

 Power switch on (IG) 4.5 to 5.5 V
Idling

Pulse generation

(see waveform 1)
B31-74 (NE+) - B31-120 (NE-) B - W Crankshaft position sensor Idling with warm engine

Pulse generation

(see waveform 2)
B31-76 (G2+) - B31-122 (G2-) B - W Camshaft position sensor Idling with warm engine

Pulse generation

(see waveform 2)
B31-85 (#10) - B31-109 (E01) Y - BR Fuel injector assembly Power switch on (IG) 11 to 14 V
B31-84 (#20) - B31-109 (E01) B - BR
B31-83 (#30) - B31-109 (E01) L - BR
B31-82 (#40) - B31-109 (E01) R - BR
B31-85 (#10) - B31-109 (E01) Y - BR Idling

Pulse generation

(see waveform 3)
B31-84 (#20) - B31-109 (E01) B - BR
B31-83 (#30) - B31-109 (E01) L - BR
B31-82 (#40) - B31-109 (E01) R - BR
B31-18 (HA1A) - B31-46 (E04) Y - BR Air fuel ratio sensor (sensor 1) heater Power switch on (IG) 11 to 14 V
Idling with warm engine

Pulse generation

(see waveform 4)
B31-103 (A1A+) - B31-104 (E1) Y - BR Air fuel ratio sensor (sensor 1) Idling 3.3 V*
B31-126 (A1A-) - B31-104 (E1) BR - BR Air fuel ratio sensor (sensor 1) Idling 3.0 V*
B31-41 (HT1B) - B31-86 (E03) BR - BR Heated oxygen sensor (sensor 2) heater Power switch on (IG) 11 to 14 V
Idling Below 3.0 V
B31-125 (OX1B) - B31-102 (O1B-) L - P Heated oxygen sensor (sensor 2) Engine speed maintained at 2500 rpm for 2 minutes after warming up engine

Pulse generation

(see waveform 5)
B31-87 (KNK1) - B31-110 (EKNK) B - W Knock control sensor Engine speed maintained at 4000 rpm after warming up engine

Pulse generation

(see waveform 6)
B31-64 (THW) - B31-65 (ETHW) P - BR Engine coolant temperature sensor Idling, engine coolant temperature 80°C (176°F) 0.2 to 1.0 V
B31-116 (THA) - B31-93 (ETHA) P - BR Intake air temperature sensor (built into mass air flow meter sub-assembly) Idling, intake air temperature 20°C (68°F) 0.5 to 3.4 V
B31-94 (VG) - B31-117 (E2G) B - W Mass air flow meter sub-assembly Idling, shift lever in N, A/C switch off 0.5 to 3.0 V
A50-36 (W) - B31-104 (E1) LG - BR MIL

Power switch on (IG)

(MIL turns on)

 Below 3.0 V
Idling 11 to 14 V
B31-90 (VTA1) - B31-111 (ETA) Y - G Throttle position sensor (for engine control)

Power switch on (IG),

accelerator pedal released

(Throttle valve fully closed)

 0.5 to 1.1 V
B31-89 (VTA2) - B31-111 (ETA) B - G Throttle position sensor (for sensor malfunction detection)

Power switch on (IG), accelerator pedal released

(Throttle valve fully closed)

 2.1 to 3.1 V
B31-88 (VCTA) - B31-111 (ETA) R - G Power source of throttle position sensor (specific voltage) Power switch on (IG) 4.5 to 5.5 V
B31-21 (M+) - B31-19 (ME01) L - BR Throttle actuator Idling with warm engine

Pulse generation

(see waveform 7)
B31-20 (M-) - B31-19 (ME01) P - BR Throttle actuator Idling with warm engine

Pulse generation

(see waveform 8)
B31-28 (PRG) - B31-104 (E1) V - BR Purge VSV Power switch on (IG) 11 to 14 V
Idling, under purge control

Pulse generation

(see waveform 9)
A50-8 (FC) - B31-104 (E1) R - BR Fuel pump control Power switch on (IG) 11 to 14 V
Idling Below 1.5 V
A50-26 (TACH) - B31-104 (E1) GR - BR Engine speed Idling

Pulse generation

(see waveform 10)
A50-7 (TC) - B31-104 (E1) P - BR Terminal TC of DLC3 Power switch on (IG) 11 to 14 V
B31-36 (OC1+) - B31-59 (OC1-) Y - G Camshaft timing oil control valve assembly Idling

Pulse generation

(see waveform 11)
A50-13 (CANH) - B31-104 (E1) Y - BR CAN communication line Engine stopped and power switch on (IG)

Pulse generation

(see waveform 12)
A50-5 (CANL) - B31-104 (E1) W - BR CAN communication line Engine stopped and power switch on (IG)

Pulse generation

(see waveform 13)
A50-12 (CANP) - B31-104 (E1) B - BR CAN communication line Engine stopped and power switch on (IG)

Pulse generation

(see waveform 12)
A50-4 (CANN) - B31-104 (E1) W - BR CAN communication line Engine stopped and power switch on (IG)

Pulse generation

(see waveform 13)
A50-28 (IGSW) - B31-104 (E1) W - BR Power switch Power switch on (IG) 11 to 14 V
A50-6 (MREL) - B31-104 (E1) G - BR EFI MAIN relay Power switch on (IG) 11 to 14 V
B31-99 (VCV1) - B31-104 (E1) R - BR Power source of camshaft position sensor Power switch on (IG) 4.5 to 5.5 V
A50-10 (WPO) - B31-104 (E1) L - BR Engine water pump assembly Idling with warm engine

Pulse generation

(see waveform 14)
A50-11 (WPI) - B31-104 (E1) G - BR Engine water pump assembly Idling with warm engine

Pulse generation

(see waveform 15)
B31-72 (VCPM) - B31-71 (EPIM) L - Y Power source of manifold absolute pressure sensor Power switch on (IG) 4.5 to 5.5 V
B31-69 (PIM) - B31-71 (EPIM) B - Y Manifold absolute pressure sensor assembly Power switch on (IG) 4.0 to 5.5 V
B31-45 (EGR1) - B31-104 (E1) R - BR EGR valve assembly Idling with warm engine

Pulse generation

(see waveform 16)
B31-44 (EGR2) - B31-104 (E1) V - BR EGR valve assembly Idling with warm engine

Pulse generation

(see waveform 16)
B31-43 (EGR3) - B31-104 (E1) Y - BR EGR valve assembly Idling with warm engine

Pulse generation

(see waveform 16)
B31-42 (EGR4) - B31-104 (E1) LG - BR EGR valve assembly Idling with warm engine

Pulse generation

(see waveform 16)
B31-48 (G2O) - B31-104 (E1) Y - BR Camshaft position signal Idling

Pulse generation

(see waveform 17)
A50-22 (FANH) - B31-104 (E1) LG - BR Cooling fan relay Power switch on (IG) 11 to 14 V
A50-21 (FANL) - B31-104 (E1) L - BR Cooling fan relay Power switch on (IG) 11 to 14 V
A50-46 (PWMS) - B31-104 (E1) G - BR Power mode switch Power switch on (IG), power mode switch off 11 to 14 V
Power switch on (IG), power mode switch on 0 to 1.5 V
B31-104 (E1) - Body ground BR - Body ground Ground Always Below 1 Ω
B31-109 (E01) - Body ground BR - Body ground Ground Always Below 1 Ω
B31-81 (E02) - Body ground W-B - Body ground Ground Always Below 1 Ω
B31-86 (E03) - Body ground BR - Body ground Ground Always Below 1 Ω
B31-46 (E04) - Body ground BR - Body ground Ground Always Below 1 Ω
A50-32 (EC) - Body ground W-B - Body ground Ground Always Below 1 Ω
B31-19 (ME01) - Body ground BR - Body ground Ground Always Below 1 Ω
B31-22 (GE01) - B31-104 (E1) W-B - BR Shield earth (ground) circuit of throttle actuator Always Below 1 V

Tech Tips

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


  1. WAVEFORM 1

    A003SEME08
    Igniter IGT Signal (from ECM to Igniter) and Igniter IGF Signal (from Igniter to ECM)
    Terminal No. (Symbol) Tool Setting Condition
    B31-108 (IGT1) - B31-104 (E1) 2 V/DIV., 20 msec./DIV. Idling
    B31-107 (IGT2) - B31-104 (E1) 2 V/DIV., 20 msec./DIV. Idling
    B31-106 (IGT3) - B31-104 (E1) 2 V/DIV., 20 msec./DIV. Idling
    B31-105 (IGT4) - B31-104 (E1) 2 V/DIV., 20 msec./DIV. Idling
    B31-23 (IGF1) - B31-104 (E1) 2 V/DIV., 20 msec./DIV. Idling

    Tech Tips

    The wavelength becomes shorter as the engine speed increases.

  2. WAVEFORM 2

    A003TKXE06
    Crankshaft Position Sensor and Camshaft Position Sensor Signal
    Terminal No. (Symbol) Tool Setting Condition
    B31-74 (NE+) - B31-120 (NE-) 5 V/DIV., 20 msec./DIV. Idling with warm engine
    B31-76 (G2+) - B31-122 (G2-) 5 V/DIV., 20 msec./DIV. Idling with warm engine

    Tech Tips

    The wavelength becomes shorter as the engine speed increases.

  3. WAVEFORM 3

    A003S40E03
    No. 1 (to No. 4) Fuel Injector Assembly Signal
    Terminal No. (Symbol) Tool Setting Condition
    B31-85 (#10) - B31-109 (E01) 20 V/DIV., 20 msec./DIV. Idling
    B31-84 (#20) - B31-109 (E01) 20 V/DIV., 20 msec./DIV. Idling
    B31-83 (#30) - B31-109 (E01) 20 V/DIV., 20 msec./DIV. Idling
    B31-82 (#40) - B31-109 (E01) 20 V/DIV., 20 msec./DIV. Idling

    Tech Tips

    The wavelength becomes shorter as the engine speed increases.

  4. WAVEFORM 4

    A003RZCE03
    Air Fuel Ratio Sensor (Sensor 1) Heater Signal
    Terminal No. (Symbol) Tool Setting Condition
    B31-18 (HA1A) - B31-46 (E04) 5 V/DIV., 10 msec./DIV. Idling with warm engine

    Tech Tips

    The wavelength varies in accordance with the engine operating condition.

  5. WAVEFORM 5

    A003RV1E02
    Heated Oxygen Sensor (Sensor 2) Signal
    Terminal No. (Symbol) Tool Setting Condition
    B31-125 (OX1B) - B31-102 (O1B-) 0.2 V/DIV., 200 msec./DIV. Engine speed maintained at 2500 rpm for 2 minutes after warming up engine

    Tech Tips

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

  6. WAVEFORM 6

    A003TEME02
    Knock Control Sensor Signal
    Terminal No. (Symbol) Tool Setting Condition
    B31-87 (KNK1) - B31-110 (EKNK) 1 V/DIV., 1 msec./DIV. Engine speed maintained at 4000 rpm after warming up engine

    Tech Tips


    • The wavelength becomes shorter as the engine speed increases.

    • The waveforms and amplitudes displayed differ slightly depending on the vehicle condition.

  7. WAVEFORM 7

    A003UQQE02
    Throttle Actuator Positive Terminal Signal
    Terminal No. (Symbol) Tool Setting Condition
    B31-21 (M+) - B31-19 (ME01) 5 V/DIV., 1 msec./DIV. Idling with warm engine

    Tech Tips

    The duty ratio varies depending on the throttle actuator operation.

  8. WAVEFORM 8

    A003RQYE02
    Throttle Actuator Negative Terminal Signal
    Terminal No. (Symbol) Tool Setting Condition
    B31-20 (M-) - B31-19 (ME01) 5 V/DIV., 1 msec./DIV. Idling with warm engine

    Tech Tips

    The duty ratio varies depending on the throttle actuator operation.

  9. WAVEFORM 9

    A003T9ME17
    Purge VSV
    Terminal No. (Symbol) Tool Setting Condition
    B31-28 (PRG) - B31-104 (E1) 10 V/DIV., 20 msec./DIV. 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.

  10. WAVEFORM 10

    A003UL2E03
    Engine Speed Signal
    Terminal No. (Symbol) Tool Setting Condition
    A50-26 (TACH) - B31-104 (E1) 5 V/DIV., 10 msec./DIV. Idling

    Tech Tips

    The wavelength becomes shorter as the engine speed increases.

  11. WAVEFORM 11

    A003TKPE02
    Camshaft Timing Oil Control Valve Assembly Signal
    Terminal No. (Symbol) Tool Setting Condition
    B31-36 (OC1+) - B31-59 (OC1-) 5 V/DIV., 1 msec./DIV. Idling

  12. WAVEFORM 12

    A003UVCE02
    CAN Communication Signal (Reference)
    Terminal No. (Symbol) Tool Setting Condition
    A50-13 (CANH) - B31-104 (E1) 1 V/DIV., 10 μsec./DIV. Engine stopped and power switch on (IG)
    A50-12 (CANP) - B31-104 (E1) 1 V/DIV., 10 μsec./DIV. Engine stopped and power switch on (IG)

    Tech Tips

    The waveform varies depending on the CAN communication signal.

  13. WAVEFORM 13

    A003RR1E02
    CAN Communication Signal (Reference)
    Terminal No. (Symbol) Tool Setting Condition
    A50-5 (CANL) - B31-104 (E1) 1 V/DIV., 10 μsec./DIV. Engine stopped and power switch on (IG)
    A50-4 (CANN) - B31-104 (E1) 1 V/DIV., 10 μsec./DIV. Engine stopped and power switch on (IG)

    Tech Tips

    The waveform varies depending on the CAN communication signal.

  14. WAVEFORM 14

    A003U82E02
    Engine Water Pump Assembly Signal (from ECM to Engine Water Pump Assembly)
    Terminal No. (Symbol) Tool Setting Condition
    A50-10 (WPO) - B31-104 (E1) 5 V/DIV., 20 msec./DIV. Idling with warm engine

    Tech Tips

    The wavelength becomes shorter as the engine water pump speed increases.

  15. WAVEFORM 15

    A003U82E03
    Engine Water Pump Assembly Signal (from Engine Water Pump Assembly to ECM)
    Terminal No. (Symbol) Tool Setting Condition
    A50-11 (WPI) - B31-104 (E1) 5 V/DIV., 20 msec./DIV. Idling with warm engine

    Tech Tips

    The wavelength becomes shorter as the engine water pump speed increases.

  16. WAVEFORM 16

    A003S83E02
    EGR Valve Assembly Signal
    Terminal No. (Symbol) Tool Setting Condition
    B31-45 (EGR1) - B31-104 (E1) 20 V/DIV., 50 msec./DIV. Idling with warm engine
    B31-44 (EGR2) - B31-104 (E1) 20 V/DIV., 50 msec./DIV. Idling with warm engine
    B31-43 (EGR3) - B31-104 (E1) 20 V/DIV., 50 msec./DIV. Idling with warm engine
    B31-42 (EGR4) - B31-104 (E1) 20 V/DIV., 50 msec./DIV. Idling with warm engine

  17. WAVEFORM 17

    A003U82E04
    Camshaft Revolution Signal from ECM to Power Management Control ECU and Inverter with Converter Assembly (MG ECU)
    Terminal No. (Symbol) Tool Setting Condition
    B31-48 (G2O) - B31-104 (E1) 5 V/DIV., 20 msec./DIV. Idling

    Tech Tips

    The wavelength becomes shorter as the engine speed increases.