SFI SYSTEM TERMINALS OF ECM

B003URGE93

Tech Tips

The standard 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 voltage for that pair of 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
A76-7 (BATT) - F4-1 (E1) L - BR Battery (for measuring the battery voltage and for the ECM memory) Always 11 to 14 V
F1-1 (+BM) - F4-1 (E1) P - BR Power source of throttle actuator Always 11 to 14 V
A76-8 (IGSW) - F4-1 (E1) LG - BR Engine switch Engine switch on (IG) 11 to 14 V
A77-2 (+B) - F4-1 (E1) B-R - BR Power source of ECM Engine switch on (IG) 11 to 14 V
A77-1 (+B2) - F4-1 (E1) B-R - BR Power source of ECM Engine switch on (IG) 11 to 14 V
F1-12 (OC1+) - F1-11 (OC1-) W - Y Camshaft timing oil control valve assembly (for intake camshaft of bank 1) operation signal Idling

Pulse generation

(see waveform 1)
F1-10 (OC2+) - F1-9 (OC2-) LG - L Camshaft timing oil control valve assembly (for intake camshaft of bank 2) operation signal Idling

Pulse generation

(see waveform 1)
F2-4 (OE1+) - F2-3 (OE1-) LG - B Camshaft timing oil control valve assembly (for exhaust camshaft of bank 1) operation signal Idling

Pulse generation

(see waveform 2)
F3-18 (OE2+) - F3-28 (OE2-) W - G Camshaft timing oil control valve assembly (for exhaust camshaft of bank 2) operation signal Idling

Pulse generation

(see waveform 2)
A76-3 (MREL) - F4-1 (E1) Y - BR EFI MAIN relay operation signal Engine switch on (IG) 11 to 14 V
F2-34 (VCTA) - F2-35 (ETA) G - R Power source for throttle position sensor (specific voltage) Engine switch on (IG) 4.5 to 5.5 V
F1-18 (VC) - F4-1 (E1) L - BR Power source for sensor (specific voltage) Engine switch on (IG) 4.5 to 5.5 V
F1-25 (VG) - F1-24 (E2G) R - W Mass air flow meter sub-assembly signal Idling, Shift lever position P or N, A/C switch OFF 0.5 to 3.0 V
F1-22 (THA) - F1-28 (E2) G - BR Intake air temperature sensor Idling, Intake air temperature 0 to 80°C (32 to 176°F) 0.5 to 3.4 V
F1-19 (THW) - F1-28 (E2) R - BR Engine coolant temperature sensor Idling, Engine coolant temperature 60 to 120°C (140 to 248°F) 0.2 to 1.0 V
F2-26 (VTA) - F2-35 (ETA) W - R Throttle position sensor signal (for engine control) Accelerator pedal fully released 0.5 to 1.1 V
Accelerator pedal fully depressed (engine running) 3.2 to 4.8 V
F2-27 (VTA2) - F2-35 (ETA) L - R Throttle position sensor signal (for sensor malfunction detection) Accelerator pedal fully released 2.1 to 3.1 V
Accelerator pedal fully depressed (engine running) 4.6 to 5.0 V
A77-29 (NSW) - F4-1 (E1) L - BR Park/Neutral position switch assembly signal Engine switch on (IG) and shift lever in P or N Below 1 V
A76-4 (IREL) - F4-1 (E1) B - BR INJ relay operation signal Engine switch on (IG) 11 to 14 V
A76-29 (VPA) - A76-20 (EPA) G - L Accelerator pedal position sensor signal (for engine control) Engine switch on (IG), accelerator pedal fully released 0.5 to 1.1 V
Engine switch on (IG), accelerator pedal fully depressed 2.6 to 4.5 V
A76-28 (VPA2) - A76-21 (EPA2) P - B Accelerator pedal position sensor signal Engine switch on (IG), accelerator pedal fully released 1.2 to 2.0 V
Engine switch on (IG), accelerator pedal fully depressed 3.4 to 4.75 V
A76-23 (VCPA) - A76-20 (EPA) R - L Power source of accelerator pedal position sensor (for VPA) Engine switch on (IG) 4.5 to 5.5 V
A76-22 (VCP2) - A76-21 (EPA2) R - B Power source of accelerator pedal position sensor (for VPA2) Engine switch on (IG) 4.5 to 5.5 V
A76-14 (KD) - F4-1 (E1) B - BR Kick down switch signal Engine switch on (IG), accelerator pedal released 11 to 14 V

F4-5 (HA1A) - F4-4 (E04)

F4-6 (HA2A) - F3-1 (E05)

Y - W-B

B - W-B

 Air fuel ratio sensor (sensor 1) heater operation signal Engine switch on (IG) 11 to 14 V
Idling

Pulse generation

(see waveform 3)
F3-23 (A1A+) - F4-1 (E1) R - BR Air fuel ratio sensor (bank 1 sensor 1) signal Engine switch on (IG) 3.3 V*1
F3-21 (A2A+) - F4-1 (E1) B - BR Air fuel ratio sensor (bank 2 sensor 1) signal Engine switch on (IG) 3.3 V*1
F3-22 (A1A-) - F4-1 (E1) G - BR Air fuel ratio sensor (bank 1 sensor 1) signal Engine switch on (IG) 2.9 V*1
F3-20 (A2A-) - F4-1 (E1) W - BR Air fuel ratio sensor (bank 2 sensor 1) signal Engine switch on (IG) 2.9 V*1

A77-4 (HT1B) - A77-5 (E03)

A77-3 (HT2B) - A77-5 (E03)

L - W-B

P - W-B

 Heated oxygen sensor (sensor 2) heater operation signal Engine switch on (IG) 11 to 14 V
Idling Below 3.0 V

A77-26 (OX1B) - F1-28 (E2)

A77-27 (OX2B) - F1-28 (E2)

G - BR

W - BR

 Heated oxygen sensor (sensor 2) signal Engine speed maintained at 2500 rpm for 2 minutes after warming up engine

Pulse generation

(see waveform 4)

F4-20 (#1) - F4-1 (E1)

F4-10 (#2) - F4-1 (E1)

F4-9 (#3) - F4-1 (E1)

F4-19 (#4) - F4-1 (E1)

F4-8 (#5) - F4-1 (E1)

F4-18 (#6) - F4-1 (E1)

LG - BR

L - BR

R - BR

P - BR

V - BR

W - BR

 Fuel injector assembly (for direct injection) signal Engine switch on (IG) 0 to 5.0 V
Idling with warm engine

Pulse generation

(see waveform 5, 16)

F3-17 (#10) - F2-2 (E01)

F2-11 (#20) - F2-2 (E01)

F3-16 (#30) - F2-2 (E01)

F2-10 (#40) - F2-2 (E01)

F3-15 (#50) - F2-2 (E01)

F2-9 (#60) - F2-2 (E01)

Y - W-B

G - W-B

L - W-B

BR - W-B

P - W-B

R - W-B

 Fuel injector assembly (for port injection) signal Engine switch on (IG) 0 to 5.0 V
Idling, engine coolant temperature 60°C or less

Pulse generation

(see waveform 6)
F4-26 (KNK1) - F4-33 (EKNK) B - W Knock control sensor (bank 1) signal Engine speed maintained at 4000 rpm after warming up engine

Pulse generation

(see waveform 7)
F4-25 (KNK2) - F4-32 (EKN2) R - G Knock control sensor (bank 2) signal Engine speed maintained at 4000 rpm after warming up engine

Pulse generation

(see waveform 7)
F2-24 (VV1+) - F2-32 (VV1-) Y - V VVT sensor (for intake camshaft of bank 1) signal Idling with warm engine

Pulse generation

(see waveform 8)
F3-19 (VV2+) - F3-29 (VV2-) GR - W VVT sensor (for intake camshaft of bank 2) signal Idling with warm engine

Pulse generation

(see waveform 8)
F1-27 (NE+) - F1-34 (NE-) W - B Crankshaft position sensor signal Idling with warm engine

Pulse generation

(see waveform 8, 9)
F1-26 (EV1+) - F1-33 (EV1-) P - LG VVT sensor (for exhaust camshaft of bank 1) signal Idling with warm engine

Pulse generation

(see waveform 9)
F4-22 (EV2+) - F4-29 (EV2-) G - R VVT sensor (for exhaust camshaft of bank 2) signal Idling with warm engine

Pulse generation

(see waveform 9)
F3-27 (IGT1) - F4-1 (E1) V - BR No. 1 ignition coil assembly (ignition signal) Idling with warm engine

Pulse generation

(see waveform 10)
F2-23 (IGT2) - F4-1 (E1) L - BR No. 2 ignition coil assembly (ignition signal) Idling with warm engine

Pulse generation

(see waveform 10)
F3-26 (IGT3) - F4-1 (E1) Y - BR No. 3 ignition coil assembly (ignition signal) Idling with warm engine

Pulse generation

(see waveform 10)
F2-22 (IGT4) - F4-1 (E1) P - BR No. 4 ignition coil assembly (ignition signal) Idling with warm engine

Pulse generation

(see waveform 10)
F3-25 (IGT5) - F4-1 (E1) V - BR No. 5 ignition coil assembly (ignition signal) Idling with warm engine

Pulse generation

(see waveform 10)
F2-21 (IGT6) - F4-1 (E1) W - BR No. 6 ignition coil assembly (ignition signal) Idling with warm engine

Pulse generation

(see waveform 10)

F3-32 (IGF1) - F4-1 (E1)

F2-28 (IGF2) - F4-1 (E1)

G - BR

V - BR

 Ignition coil assembly (ignition confirmation signal) Engine switch on (IG) 4.5 to 5.5 V
Idling with warm engine

Pulse generation

(see waveform 10)
F1-17 (PRG) - F4-1 (E1) W - BR Purge VSV for EVAP system operation signal Engine switch on (IG) 11 to 14 V
Idling, under purge control

Pulse generation

(see waveform 11)
A76-24 (SPD) - F4-1 (E1) P - BR Vehicle speed signal from combination meter assembly Driving at 20 km/h (12 mph)

Pulse generation

(see waveform 12)
A77-20 (STA) - F4-1 (E1) R - BR Starter signal Cranking 5.5 V or higher
A76-13 (STP) - F4-1 (E1) R - BR Stop light switch assembly signal Brake pedal depressed 7.5 to 14 V
Brake pedal released Below 1.5 V
A76-12 (ST1-) - F4-1 (E1) P - BR Stop light switch assembly signal (opposite to STP terminal) Engine switch on (IG), Brake pedal depressed Below 1.5 V
Engine switch on (IG), Brake pedal released 7.5 to 14 V
F2-7 (M+) - F2-5 (ME01) B - W-B Throttle actuator operation signal (positive terminal) Idling with warm engine

Pulse generation

(see waveform 13)
F2-6 (M-) - F2-5 (ME01) W - W-B Throttle actuator operation signal (negative terminal) Idling with warm engine

Pulse generation

(see waveform 14)
A76-5 (FPC) - F4-1 (E1) P - BR Fuel pump control Engine stopped, engine switch on (IG) Below 1.5 V
A77-21 (TC) - F4-1 (E1) V - BR Terminal TC of DLC3 Engine switch on (IG) 11 to 14 V
A76-15 (TACH) - F4-1 (E1) W - BR Engine speed signal Idling with warm engine

Pulse generation

(see waveform 15)
F2-13 (INJ1) - F4-1 (E1) GR - BR Fuel injector assembly (for direct injection) confirmation signal Idling with warm engine

Pulse generation

(see waveform 16)
F2-12 (INJ2) - F4-1 (E1) B - BR Fuel injector assembly (for direct injection) confirmation signal Idling with warm engine

Pulse generation

(see waveform 16)
F2-15 (INJ3) - F4-1 (E1) Y - BR Fuel injector assembly (for direct injection) confirmation signal Idling with warm engine

Pulse generation

(see waveform 16)
F3-10 (FPF1) - F4-1 (E1) G - BR Fuel pump (for high pressure side) signal Idling with warm engine

Pulse generation

(see waveform 17)
F3-11 (FPD) - F4-1 (E1) LG - BR Fuel pump (for high pressure side) signal Idling with warm engine

Pulse generation

(see waveform 17)
F4-27 (PR) - F1-28 (E2) V - BR Fuel pressure sensor Idling with warm engine 1.0 to 1.7 V
A76-27 (NEO) - F4-1 (E1) B - BR Engine speed signal sent to certification ECU (smart key ECU assembly) Idling with warm engine

Pulse generation

(see waveform 20)
A76-25 (KSW) - F4-1 (E1) P - BR Key in vehicle signal Engine switch off → on (IG) 0 to 3.0 V
A76-19 (RFC) - F4-1 (E1) G - BR Cooling fan control Engine switch on (IG), A/C switch on (max cool)

Pulse generation

(see waveform 21)
F2-18 (ALT) - F4-1(E1) G - BR Generator assembly Engine switch on (IG) 11 to 14 V
A77-14 (CANH) - F4-1 (E1) R - BR CAN communication line Engine switch on (IG)

Pulse generation

(see waveform 18)
A77-10 (CAN+) - F4-1 (E1) B - BR CAN communication line Engine switch on (IG)

Pulse generation

(see waveform 18)
A77-13 (CANL) - F4-1 (E1) B - BR CAN communication line Engine switch on (IG)

Pulse generation

(see waveform 19)
A77-9 (CAN-) - F4-1 (E1) W - BR CAN communication line Engine switch on (IG)

Pulse generation

(see waveform 19)
A77-25 (SPCN) - F4-1 (E1) G - BR Drive mode switch signal (NORMAL mode) Engine switch on (IG) 11 to 14 V
Engine switch on (IG), NORMAL mode switch being pushed and held (NORMAL mode) Below 1.5 V
A76-23 (PWR) - F4-1 (E1) B - BR Drive mode switch signal (SPORT mode) Engine switch on (IG) 11 to 14 V
Engine switch on (IG), SPORT mode switch being turned and held at SPORT position (SPORT mode) Below 1.5 V
A77-22 (SNWI)*2 - F4-1 (E1) P - BR SNOW mode switch signal Engine switch on (IG) 11 to 14 V
Engine switch on (IG), SNOW mode switch being pushed and held (SNOW mode) Below 1.5 V
F4-11 (R) - F4-1 (E1) R - BR R shift position switch signal Engine switch on (IG), shift lever in R 11 to 14 V
Engine switch on (IG), shift lever not in R Below 1 V
F4-14 (D) - F4-1 (E1) W - BR D shift position switch signal Engine switch on (IG), shift lever in D or M 11 to 14 V
Engine switch on (IG), shift lever not in D or M Below 1 V
F4-13 (N) - F4-1 (E1) G - BR N shift position switch signal Engine switch on (IG), shift lever in N 11 to 14 V
Engine switch on (IG), shift lever not in N Below 1 V
F4-12 (P) - F4-1 (E1) B - BR Park/Neutral position switch signal Engine switch on (IG), shift lever in P 11 to 14 V
Engine switch on (IG), shift lever not in P Below 1 V
A77-16 (S) - F4-1 (E1) GR - BR M shift position switch signal Engine switch on (IG), shift lever in M 11 to 14 V
Engine switch on (IG), shift lever not in M Below 1 V
F2-19 (GE01) - F4-1 (E1) G - BR Shielded earth (ground) circuit of throttle actuator Always Below 1 Ω
F2-5 (ME01) - Body ground W-B - - Ground Always Below 1 Ω
A76-1 (EC) - Body ground W-B - - Ground Always Below 1 Ω
F4-1 (E1) - Body ground BR - - Ground Always Below 1 Ω
F2-2 (E01) - Body ground W-B - - Ground Always Below 1 Ω
F2-1 (E02) - Body ground W-B - - Ground Always Below 1 Ω
A77-5 (E03) - Body ground W-B - - Ground Always Below 1 Ω
F4-4 (E04) - Body ground W-B - - Ground Always Below 1 Ω
F3-1 (E05) - Body ground W-B - - Ground Always Below 1 Ω


  1. WAVEFORM 1

    B003TQZE01
    *a 5 V/DIV.
    *b 1 ms./DIV.
    Camshaft Timing Oil Control Valve Assembly (for Intake Camshaft) Operation Signal
    ECM Terminal Name Between OC1+ and OC1-, or OC2+ and OC2-
    Tester Range 5 V/DIV., 1 ms./DIV.
    Condition Idling

  2. WAVEFORM 2

    B003TQZE01
    *a 5 V/DIV.
    *b 1 ms./DIV.
    Camshaft Timing Oil Control Valve Assembly (for Exhaust Camshaft) Operation Signal
    ECM Terminal Name Between OE1+ and OE1-, or OE2+ and OE2-
    Tester Range 5 V/DIV., 1 ms./DIV.
    Condition Idling

  3. WAVEFORM 3

    B003WKRE01
    *a 5 V/DIV.
    *b 10 ms./DIV.
    Air Fuel Ratio Sensor (Sensor 1) Heater Operation Signal
    ECM Terminal Name Between HA1A and E04, or HA2A and E05
    Tester Range 5 V/DIV., 10 ms./DIV.
    Condition Idling

  4. WAVEFORM 4

    B003VO1E01
    *1 0.2 V/DIV.
    *2 200 ms./DIV.
    Heated Oxygen Sensor (Sensor 2) Signal
    ECM Terminal Name Between OX1B and E2, or OX2B and E2
    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, item O2S B1S2 and O2S B2S2 shows the ECM values from the heated oxygen sensor.

  5. WAVEFORM 5

    B003TXPE01
    *a 2 V/DIV.
    *b 20 ms./DIV.
    Fuel Injector Assembly (for Direct Injection) Signal
    ECM Terminal Name Between #1 (to #6) and E1
    Tester Range 2 V/DIV., 20 ms./DIV.
    Condition Idling with warm engine

    Tech Tips


    • The wavelength becomes shorter as the engine speed increases.

    • When the direct injection injectors are operating, Direct is displayed for Injection Way of the Data List.

  6. WAVEFORM 6

    B003WTLE01
    *1 20 V/DIV.
    *2 20 ms./DIV.
    Fuel Injector Assembly (for Port Injection) Signal
    ECM Terminal Name Between #10 (to #60) and E01
    Tester Range 20 V/DIV., 20 ms./DIV.
    Condition Idling, engine coolant temperature 60°C or less

    Tech Tips


    • The wavelength becomes shorter as the engine speed increases.

    • When the port injection injectors are operating, Port is displayed for Injection Way of the Data List.

  7. WAVEFORM 7

    B003W6GE06
    *a 1 V/DIV.
    *b 1 ms./DIV.
    Knock Control Sensor Signal
    ECM Terminal Name Between KNK1 and EKNK, or KNK2 and EKN2
    Tester Range 1 V/DIV., 1 ms./DIV.
    Condition 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.

  8. WAVEFORM 8

    B003WZ9E01
    *a 5 V/DIV.
    *b 20 ms./DIV.
    Crankshaft Position Sensor Signal and VVT Sensor (for Intake Camshaft) Signal
    ECM Terminal Name

    Between NE+ and NE-

    Between VV1+ and VV1-

    Between VV2+ and VV2-
    Tester Range 5 V/DIV., 20 ms./DIV.
    Condition Idling with warm engine

    Tech Tips

    The wavelength becomes shorter as the engine speed increases.

  9. WAVEFORM 9

    B003W6SE01
    *a 5 V/DIV.
    *b 20 ms./DIV.
    Crankshaft Position Sensor Signal and VVT Sensor (for Exhaust Camshaft) Signal
    ECM Terminal Name

    Between NE+ and NE-

    Between EV1+ and EV1-

    Between EV2+ and EV2-
    Tester Range 5 V/DIV., 20 ms./DIV.
    Condition Idling with warm engine

    Tech Tips

    The wavelength becomes shorter as the engine speed increases.

  10. WAVEFORM 10

    B003V8BE02
    *a 2 V/DIV.
    *b 20 ms./DIV.
    Ignition Coil Assembly Signal (IGT and IGF Signal)
    ECM Terminal Name

    CH1: IGT1, 3 or 5 and E1

    CH2: IGF1 and E1

    CH1: IGT2, 4 or 6 and E1

    CH2: IGF2 and E1
    Tester Range 2 V/DIV., 20 ms./DIV.
    Condition Idling with warm engine

    Tech Tips

    The wavelength becomes shorter as the engine speed increases.

  11. WAVEFORM 11

    B003TZTE01
    *1 10 V/DIV.
    *2 20 ms./DIV.
    Purge VSV Operation Signal
    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.

  12. WAVEFORM 12

    B003V5RE01
    *a 5 V/DIV.
    *b 20 ms./DIV.
    Vehicle Speed Signal
    ECM Terminal Name Between SPD and E1
    Tester Range 5 V/DIV., 20 ms./DIV.
    Condition Driving at 20 km/h (12 mph)

    Tech Tips

    The wavelength becomes shorter as the vehicle speed increases.

  13. WAVEFORM 13

    B003VYZE03
    *a 5 V/DIV.
    *b 1 ms./DIV.
    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.

  14. WAVEFORM 14

    B003WQCE01
    *a 5 V/DIV.
    *b 1 ms./DIV.
    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.

  15. WAVEFORM 15

    B003T2ME01
    *a 5 V/DIV.
    *b 10 ms./DIV.
    Engine Speed Signal
    ECM Terminal Name Between TACH and E1
    Tester Range 5 V/DIV., 10 ms./DIV.
    Condition Idling with warm engine

    Tech Tips

    The wavelength becomes shorter as the engine speed increases.

  16. WAVEFORM 16

    B003UF6E11
    *a 2 V/DIV.
    *b 20 ms./DIV
    Fuel Injector Assembly (for Direct Injection) Signal and Injection Confirmation Signal
    ECM Terminal Name

    CH1: Between #1 or #4 and E1

    CH2: Between INJ1 and E1

    CH1: Between #2 or #5 and E1

    CH2: Between INJ2 and E1

    CH1: Between #3 or #6 and E1

    CH2: Between INJ3 and E1
    Tester Range 2 V/DIV., 20 ms./DIV.
    Condition Idling with warm engine

    Tech Tips


    • The wavelength becomes shorter as the engine speed increases.

    • When the direct injection injectors are operating, Direct is displayed for Injection Way of the Data List.

  17. WAVEFORM 17

    B003VA0E04
    *a 2 V/DIV.
    *b 5 ms./DIV.
    Fuel Pump for High Pressure Side Signal (Spill Control Valve)
    ECM Terminal Name

    CH1: Between FPD and E1

    CH2: Between FPF1 and E1
    Tester Range 2 V/DIV., 5 ms./DIV.
    Condition Idling with warm engine

  18. WAVEFORM 18

    B003WPQE01
    *a 1 V/DIV.
    *b 10 μs./DIV.
    CAN Communication Signal (Reference)
    ECM Terminal Name

    Between CANH and E1

    Between CAN+ and E1
    Tester Range 1 V/DIV., 10 μs./DIV.
    Condition Engine switch on (IG)

    Tech Tips

    The waveform varies depending on the CAN communication signal.

  19. WAVEFORM 19

    B003WFSE03
    *a 1 V/DIV.
    *b 10 μs./DIV.
    CAN Communication Signal (Reference)
    ECM Terminal Name

    Between CANL and E1

    Between CAN- and E1
    Tester Range 1 V/DIV., 10 μs./DIV.
    Condition Engine switch on (IG)

    Tech Tips

    The waveform varies depending on the CAN communication signal.

  20. WAVEFORM 20

    B003TJ9E01
    *a 1 V/DIV.
    *b 2 ms./DIV.
    Engine Speed Signal
    ECM Terminal Name Between NEO and E1
    Tester Range 1 V/DIV., 2 ms./DIV.
    Condition Idling with warm engine

    Tech Tips

    The wavelength becomes shorter as the engine speed increases.

  21. WAVEFORM 21

    B003VYKE07
    *a 1 V/DIV.
    *b 20 ms./DIV.
    Cooling Fan Control Signal
    ECM Terminal Name Between RFC and E1
    Tester Range 1 V/DIV., 20 ms./DIV.
    Condition Engine switch on (IG), A/C switch on (max cool)

    Tech Tips

    The duty ratio varies depending on the engine coolant temperature.