SFI SYSTEM TERMINALS OF ECM

A01HVE4E02

Tech Tips

The standard voltage between each pair of ECM terminals is shown in the table below. The appropriate conditions for checking each pair of terminals are also indicated. The result of checks should be compared with the standard 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
A25-1 (BATT) - E28-16 (E1) GR - BR Auxiliary battery (for measuring auxiliary battery voltage and for ECM memory) Always 11 to 14 V
A25-2 (+B) - E28-16 (E1) P - BR Power source of ECM Power switch on (IG) 11 to 14 V
A25-3 (+B2) - E28-16 (E1) LG - BR Power source of ECM Power switch on (IG) 11 to 14 V
E28-29 (+BM) - E28-16 (E1) B - BR Power source of throttle actuator Always 11 to 14 V
A25-37 (IGSW) - E28-16 (E1) V - BR Power switch on (IG) signal Power switch on (IG) 11 to 14 V
E28-74 (OC1+) - E28-75 (OC1-) W - B Camshaft timing oil control valve assembly operation signal Idling

Pulse generation

(See waveform 1)
A25-46 (MREL) - E28-16 (E1) BE - BR EFI MAIN relay operation signal Power switch on (IG) 11 to 14 V
E28-91 (VG) - E28-92 (E2G) L - R Mass air flow meter sub-assembly signal Idling, shift lever in P, A/C switch off 0.5 to 3.0 V
E28-93 (THA) - E28-94 (ETHA) P - Y Intake air temperature sensor signal Idling, intake air temperature 20°C (68°F) 0.5 to 3.4 V
E28-95 (THW) - E28-96 (ETHW) B - P Engine coolant temperature sensor signal Idling, engine coolant temperature 80°C (176°F) 0.2 to 1.0 V
E28-125 (VCTA) - E28-126 (ETA) B - R Power source of throttle position sensor (specific voltage) Power switch on (IG) 4.5 to 5.5 V
E28-127 (VTA1) - E28-126 (ETA) Y - R Throttle position sensor signal (for engine control) Accelerator pedal fully released 0.5 to 1.1 V
E28-128 (VTA2) - E28-126 (ETA) W - R Throttle position sensor signal (for sensor malfunction detection) Accelerator pedal fully released 2.1 to 3.1 V
E28-23 (HA1A) - E28-53 (E04) G - W-B Air fuel ratio sensor heater operation signal Idling

Pulse generation

(See waveform 2)
Power switch on (IG) 11 to 14 V
E28-133 (A1A+) - E28-16 (E1) L - BR Air fuel ratio sensor signal Power switch on (IG) 3.3 V*
E28-134 (A1A-) - E28-16 (E1) P - BR Air fuel ratio sensor signal Power switch on (IG) 2.9 V*
E28-24 (HT1B) - E28-53 (E04) Y - W-B Heated oxygen sensor heater operation signal Idling Below 3.0 V
Power switch on (IG) 11 to 14 V
E28-100 (OX1B) - E28-132 (EX1B) W - R Heated oxygen sensor signal Engine speed maintained at 2500 rpm for 2 minutes after warming up engine

Pulse generation

(See waveform 3)
E28-20 (#10) - E28-50 (E01) B - W-B No. 1 fuel injector assembly signal Power switch on (IG) 11 to 14 V
Idling

Pulse generation

(See waveform 4)
E28-17 (#20) - E28-50 (E01) R - W-B No. 2 fuel injector assembly signal Power switch on (IG) 11 to 14 V
Idling

Pulse generation

(See waveform 4)
E28-18 (#30) - E28-50 (E01) Y - W-B No. 3 fuel injector assembly signal Power switch on (IG) 11 to 14 V
Idling

Pulse generation

(See waveform 4)
E28-19 (#40) - E28-50 (E01) L - W-B No. 4 fuel injector assembly signal Power switch on (IG) 11 to 14 V
Idling

Pulse generation

(See waveform 4)
E28-123 (KNK1) - E28-124 (EKNK) R - G Knock control sensor signal Engine speed maintained at 2500 rpm after warming up engine

Pulse generation

(See waveform 5)
E28-113 (VCV1) - E28-16 (E1) B - BR Power source of camshaft position sensor (specific voltage) Power switch on (IG) 4.5 to 5.5 V
E28-82 (VV1+) - E28-114 (VV1-) V - L Camshaft position sensor signal Idling

Pulse generation

(See waveform 6)
A25-60 (G2O) - E28-16 (E1) B - BR Camshaft revolution signal Idling

Pulse generation

(See waveform 7)
E28-76 (NE+) - E28-109 (NE-) B - W Crankshaft position sensor signal Idling

Pulse generation

(See waveform 8)
E28-57 (IGT1) - E28-16 (E1) Y - BR No. 1 ignition coil assembly (ignition signal) Idling

Pulse generation

(See waveform 9)
E28-56 (IGT2) - E28-16 (E1) R - BR No. 2 ignition coil assembly (ignition signal) Idling

Pulse generation

(See waveform 9)
E28-55 (IGT3) - E28-16 (E1) G - BR No. 3 ignition coil assembly (ignition signal) Idling

Pulse generation

(See waveform 9)
E28-54 (IGT4) - E28-16 (E1) L - BR No. 4 ignition coil assembly (ignition signal) Idling

Pulse generation

(See waveform 9)
E28-51 (IGF1) - E28-16 (E1) W - BR Ignition coil assembly (ignition confirmation signal) Power switch on (IG) 4.5 to 5.5 V
Idling

Pulse generation

(See waveform 9)
E28-68 (PRG) - E28-50 (E01) W - W-B Purge VSV operation signal Power switch on (IG) 11 to 14 V
Idling, under purge control

Pulse generation

(See waveform 10)
E28-60 (M+) - E28-58 (ME01) W - W-B

Throttle actuator operation signal

(positive terminal)

 Idling with warm engine

Pulse generation

(See waveform 11)
E28-30 (M-) - E28-58 (ME01) B - W-B

Throttle actuator operation signal

(negative terminal)

 Idling with warm engine

Pulse generation

(See waveform 12)
A25-21 (FC) - E28-50 (E01) R - W-B Fuel pump control Power switch on (IG) 11 to 14 V
A25-30 (W) - E28-16 (E1) Y - BR Malfunction Indicator Lamp (MIL) operation signal

Power switch on (IG)

(MIL goes on)

 Below 3.0 V
Idling 11 to 14 V
A25-23 (TC) - E28-16 (E1) P - BR Terminal TC of DLC3 Power switch on (IG) 11 to 14 V
A25-31 (TACH) - E28-16 (E1) L - BR Engine speed signal Idling

Pulse generation

(See waveform 13)
A25-34 (VCPP) - A25-48 (EPPM) Y - G Power source of canister pressure sensor (specific voltage) Power switch on (IG) 4.5 to 5.5 V
A25-7 (VPMP) - E28-50 (E01) GR - W-B Vent valve (built into canister pump module) Power switch on (IG) 11 to 14 V
A25-19 (MPMP) - E28-50 (E01) B - W-B Leak detection pump (built into canister pump module) Leak detection pump off Below 3.0 V
Leak detection pump on 9 to 14 V
A25-49 (PPMP) - A25-48 (EPPM) B - G Canister pressure sensor (built into canister pump module) Power switch on (IG) 3.0 to 3.6 V
A25-13 (CANH) - E28-16 (E1) B - BR CAN communication line Power switch on (IG)

Pulse generation

(See waveform 14)
A25-26 (CANL) - E28-16 (E1) W - BR CAN communication line Power switch on (IG)

Pulse generation

(See waveform 15)
A25-12 (CANP) - E28-16 (E1) B - BR CAN communication line Power switch on (IG)

Pulse generation

(See waveform 14)
A25-25 (CANN) - E28-16 (E1) W -BR CAN communication line Power switch on (IG)

Pulse generation

(See waveform 15)
A25-28 (WPI) - E28-16 (E1) BE -BR Engine water pump assembly signal Idling with warm engine

Pulse generation

(See waveform 16)
A25-29 (WPO) - E28-16 (E1) LG - BR Engine water pump assembly signal Idling with warm engine

Pulse generation

(See waveform 17)
E28-78 (VCPM) - E28-80 (EPIM) B - V Power source of manifold absolute pressure sensor Power switch on (IG) 4.75 to 5.25 V
E28-79 (PIM) - E28-80 (EPIM) G - V Manifold absolute pressure sensor signal Power switch on (IG) 3.0 to 5.0 V
E28-28 (EGR1) - E28-16 (E1) L - BR EGR valve assembly EGR valve operating

Pulse generation

(See waveform 18)
E28-27 (EGR2) - E28-16 (E1) W - BR EGR valve assembly EGR valve operating

Pulse generation

(See waveform 18)
E28-26 (EGR3) - E28-16 (E1) R - BR EGR valve assembly EGR valve operating

Pulse generation

(See waveform 18)
E28-25 (EGR4) - E28-16 (E1) B - BR EGR valve assembly EGR valve operating

Pulse generation

(See waveform 18)
A25-44 (RFC) - E28-16 (E1) G - BR Cooling fan control

Power switch on (IG),

A/C switch on (max cool)

Pulse generation

(See waveform 19)
A25-14 (EC) - Body ground W-B - - Earth (ground) circuit of ECM Always Below 1 Ω
E28-16 (E1) - Body ground BR- - Earth (ground) circuit of ECM Always Below 1 Ω
E28-50 (E01) - Body ground W-B - - Earth (ground) circuit of ECM Always Below 1 Ω
E28-49 (E02) - Body ground W-B - - Earth (ground) circuit of ECM Always Below 1 Ω
E28-53 (E04) - Body ground BR- - Earth (ground) circuit of ECM Always Below 1 Ω
E28-58 (ME01) - Body ground W-B - - Earth (ground) circuit of ECM Always Below 1 Ω
E28-59 (GE01) - Body ground R - - Shielded earth (ground) circuit of throttle actuator Always Below 1 Ω

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


  1. WAVEFORM 1

    A01HUPPE38
    Camshaft Timing Oil Control Valve Assembly Signal
    ECM Terminal Name Between OC1+ and OC1-
    Tester Range 5 V/DIV., 1 ms./DIV.
    Condition Idling

  2. WAVEFORM 2

    A01HV9BE01
    Air Fuel Ratio Sensor (Sensor 1) Heater Operation Signal
    ECM Terminal Name Between HA1A and E04
    Tester Range 5 V/DIV., 10 ms./DIV.
    Condition Idling

  3. WAVEFORM 3

    A01HUVIE15
    Heated Oxygen Sensor (Sensor 2) Signal
    ECM Terminal Name Between OX1B and EX1B
    Tester Range 0.2 V/DIV., 200 ms./DIV.
    Condition Engine speed maintained at 2500 rpm for 2 minutes after warming up engine

    Tech Tips

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

  4. WAVEFORM 4

    A01HVKEE24
    No. 1 (to No. 4) Fuel Injector Assembly Signal
    ECM Terminal Name Between #10 (to #40) and E01
    Tester Range 20 V/DIV., 20 ms./DIV.
    Condition Idling

    Tech Tips

    The wavelength becomes shorter as the engine speed increases.

  5. WAVEFORM 5

    A01HTR6E82
    Knock Control Sensor Signal
    ECM Terminal Name Between KNK1 and EKNK
    Tester Range 1 V/DIV., 1 ms./DIV.
    Condition Engine speed maintained at 2500 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.

  6. WAVEFORM 6

    A01HTQXE01
    Camshaft Position Sensor Signal
    ECM Terminal Name Between VV1+ and VV1-
    Tester Range 5 V/DIV., 20 ms./DIV.
    Condition Idling

    Tech Tips

    The wavelength becomes shorter as the engine speed increases.

  7. WAVEFORM 7

    A01HTO7E01
    Camshaft Revolution Signal from ECM to Power Management Control ECU and Inverter with Converter Assembly
    ECM Terminal Name Between G2O and E1
    Tester Range 5 V/DIV., 20 ms./DIV.
    Condition Idling

    Tech Tips

    The wavelength becomes shorter as the engine speed increases.

  8. WAVEFORM 8

    A01HTCOE02
    Crankshaft Position Sensor Signal
    ECM Terminal Name Between NE+ and NE-
    Tester Range 5 V/DIV., 20 ms./DIV.
    Condition Idling

    Tech Tips

    The wavelength becomes shorter as the engine speed increases.

  9. WAVEFORM 9

    A01HUXWE01
    Ignition Coil Assembly Signal (IGT and IGF Signal)
    ECM Terminal Name

    CH1: Between IGT (1 to 4) and E1

    CH2: Between IGF1 and E1
    Tester Range 2 V/DIV., 20 ms./DIV.
    Condition Idling

    Tech Tips

    The wavelength becomes shorter as the engine speed increases.

  10. WAVEFORM 10

    A01HU3BE01
    Purge VSV Signal
    ECM Terminal Name Between PRG and E01
    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.

  11. WAVEFORM 11

    A01HULDE03
    Throttle Actuator Positive Terminal Signal
    ECM Terminal Name Between M+ and ME01
    Tester Range 5 V/DIV., 1 ms./DIV.
    Condition Idling with warm engine

    Tech Tips

    The duty ratio varies depending on the throttle actuator operation.

  12. WAVEFORM 12

    A01HSQPE01
    Throttle Actuator Negative Terminal Signal
    ECM Terminal Name Between M- and ME01
    Tester Range 5 V/DIV., 1 ms./DIV.
    Condition Idling with warm engine

    Tech Tips

    The duty ratio varies depending on the throttle actuator operation.

  13. WAVEFORM 13

    A01HT08E33
    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 speed increases.

  14. WAVEFORM 14

    A01HUDJE48
    CAN Communication Signal (Reference)
    ECM Terminal Name Between CANH and E1, or CANP and E1
    Tester Range 1 V/DIV., 10 μs./DIV.
    Condition Power switch on (IG)

    Tech Tips

    The waveform varies depending on the CAN communication signal.

  15. WAVEFORM 15

    A01HSGQE44
    CAN Communication Signal (Reference)
    ECM Terminal Name Between CANL and E1, or CANN and E1
    Tester Range 1 V/DIV., 10 μs./DIV.
    Condition Power switch on (IG)

    Tech Tips

    The waveform varies depending on the CAN communication signal.

  16. WAVEFORM 16

    A01HTO7E01
    Engine Water Pump Assembly Signal (from Engine Water Pump Assembly to ECM)
    ECM Terminal Name Between WPI and E1
    Tester Range 5 V/DIV., 20 ms./DIV.
    Condition Idling with warm engine

    Tech Tips

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

  17. WAVEFORM 17

    A01HTO7E01
    Engine Water Pump Assembly Signal (from ECM to Engine Water Pump Assembly)
    ECM Terminal Name Between WPO and E1
    Tester Range 5 V/DIV., 20 ms./DIV.
    Condition Idling with warm engine

    Tech Tips

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

  18. WAVEFORM 18

    A01HVKBE01
    EGR Valve Assembly Signal
    ECM Terminal Name

    Between EGR1 and E1

    Between EGR2 and E1

    Between EGR3 and E1

    Between EGR4 and E1
    Tester Range 20 V/DIV., 50 ms./DIV.
    Condition EGR valve operating

  19. WAVEFORM 19

    A01HSOGE01
    Cooling Fan Control Signal
    ECM Terminal Name Between RFC and E1
    Tester Range 1 V/DIV., 20 ms./DIV.
    Condition Power switch on (IG), A/C switch on (max cool)

    Tech Tips

    The duty ratio varies depending on the engine coolant temperature.