LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 2012 >> Camry L >> Repair and Diagnosis >> External Pages >> Different car >> Section 19 (Engine Control System (Diagnostics - Introduction)) >> SFI System >> Terminals Of ECM >> Terminals Of ECM
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Terminals Of ECM

WARNING: This page is about a different car, the 2012 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.
  1. SFI SYSTEM 
    Fig 1: ECM Connector Terminal Identification - SFI System
    GTY190962Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    HINT: 

    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 check results should be compared with the standard normal voltage for that pair of terminals, listed 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
    A55-2 (+B) - B50-81 (E1) R - W-B Power source of ECM Ignition switch to ON 11 to 14 V
    A55-1 (+B2) - B50-81 (E1) W - W-B Power source of ECM Ignition switch to ON 11 to 14 V
    A55-20 (BATT) - B50-81 (E1) B - W-B Battery (for measuring the battery voltage and for the ECM memory) Always 11 to 14 V
    A55-42 (VPMP) - B50-81 (E1) W - W-B Vent valve operation signal (built into canister pump module) Ignition switch to ON 11 to 14 V
    A55-34 (MPMP) - B50-81 (E1) G - W-B Leak detection pump operation signal (built into canister pump module) Leak detection pump OFF 0 to 3 V
    A55-34 (MPMP) - B50 -81 (E1) G - W-B Leak detection pump operation signal (built into canister pump module) Leak detection pump ON 9 to 14 V
    A55-3 (+BM)- B50-81 (E1) LG - W-B Power source of ETCS throttle motor Always 11 to 14 V
    A55-44 (MREL) - B50-81 (E1) BE - W-B EFI relay operation signal Ignition switch to ON 11 to 14 V
    A55-28 (IGSW) - B50-81 (E1) Y - W-B Ignition switch signal Ignition switch to ON 11 to 14 V
    A55-7 (FC) - B50-81 (E1) Y - W-B C/OPEN relay operation signal (fuel pump control) Ignition switch to ON, Engine stopped 11 to 14 V
    A55-7 (FC) - B50-81 (E1) Y - W-B C/OPEN relay operation signal (fuel pump control) Ignition switch to ON, Engine idling 0 to 1.5 V
    A55-36 (STP) - B50-81 (E1) W - W-B Stop light switch assembly signal Brake pedal depressed 7.5 to 14 V
    A55-36 (STP) - B50-81 (E1) W - W-B Stop light switch assembly signal Brake pedal released Below 1.5 V
    A55-35 (ST1-) - B50-81 (E1) GR - W-B Stop light switch assembly signal (opposite to STP terminal) Ignition switch to ON, Brake pedal depressed Below 1.5 V
    A55-35 (ST1-) - B50-81 (E1) GR - W-B Stop light switch assembly signal (opposite to STP terminal) Ignition switch to ON, Brake pedal released 7.5 to 14 V
    A55-13 (ACCR)*2 - B50-81 (E1) B - W-B ACC relay control signal Cranking Below 1.5 V
    A55-55 (VPA) - A55-59 (EPA) G - Y Accelerator pedal position sensor signal (for engine control) Ignition switch to ON, Accelerator pedal fully released 0.5 to 1.1 V
    A55-55 (VPA) - A55-59 (EPA) G - Y Accelerator pedal position sensor signal (for engine control) Ignition switch to ON, Accelerator pedal fully depressed 2.6 to 4.5 V
    A55-56 (VPA2) - A55-60 (EPA2) R - BE Accelerator pedal position sensor signal (for sensor malfunction detection) Ignition switch to ON, Accelerator pedal fully released 1.2 to 2.0 V
    A55-56 (VPA2) - A55-60 (EPA2) R - BE Accelerator pedal position sensor signal (for sensor malfunction detection) Ignition switch to ON, Accelerator pedal fully depressed 3.4 to 5.0 V
    B50-77 (PPMP) - B50-81 (E1) L - W-B Canister pressure sensor signal (built into canister pump module) Ignition switch to ON 3 to 3.6 V
    A55-27 (TC) - B50-81 (E1) P - W-B Terminal TC of DLC3 Ignition switch to ON 11 to 14 V
    A55-57 (VCPA) - A55-59 (EPA) B - Y Power source of accelerator pedal position sensor (for VPA) Ignition switch to ON 4.5 to 5.5 V
    A55-58 (VCP2) - A55-60 (EPA2) L - BE Power source of accelerator pedal position sensor (for VPA2) Ignition switch to ON 4.5 to 5.5 V
    A55-15 (TACH) - B50-81 (E1) B - W-B Engine speed signal (for combination meter assembly) Idling Pulse generation
    (see waveform 12 found in Fig 13)
    A55-8 (SPD) - B50-81 (E1) V - W-B Vehicle speed signal from combination meter assembly Ignition switch to ON, Driving wheel rotated slowly Pulse generation
    (see waveform 9 found in Fig 10)
    A55-24 (W) - B50-81 (E1) BR - W-B Malfunction Indicator Lamp (MIL) operation signal Ignition switch to ON
    (MIL goes on)    		 Below 3.0 V
    A55-24 (W) - B50-81 (E1) BR - W-B Malfunction Indicator Lamp (MIL) operation signal Idling 11 to 14 V
    A55-49 (CANL) - B50-81 (E1) BE - W-B CAN communication circuit Ignition switch to ON Pulse generation
    (see waveform 13 found in Fig 14)
    A55-41 (CANH) - B50-81 (E1) G - W-B CAN communication circuit Ignition switch to ON Pulse generation
    (see waveform 14 found in Fig 15)
    B50-81 (E1) - Body ground W-B - - Earth (ground) circuit of ECM Always Below 1 Ω
    B50-45 (#10) - B50-22 (E01)
    B50-85 (#20) - B50-22 (E01)
    B50-44 (#30) - B50-22 (E01)
    B50-84 (#40) - B50-22 (E01)
    B50-43 (#50) - B50-22 (E01)
    B50-83 (#60) - B50-22 (E01)    		 B - W-B
    R - W-B
    Y - W-B
    L - W-B
    W-L - W-B
    BR - W-B    		 Fuel injector assembly operation signal Ignition switch to ON 11 to 14 V
    B50-45 (#10) - B50-22 (E01)
    B50-85 (#20) - B50-22 (E01)
    B50-44 (#30) - B50-22 (E01)
    B50-84 (#40) - B50-22 (E01)
    B50-43 (#50) - B50-22 (E01)
    B50-83 (#60) - B50-22(E01)    		 B - W-B
    R - W-B
    Y - W-B
    L - W-B
    W-L - W-B
    BR - W-B    		 Fuel injector assembly operation signal Idling Pulse generation
    (see waveform 3 found in Fig 4)
    B50-115 (VCV1) - B50-81 (E1) Y - W-B Power source for VVT sensor (specific voltage) Ignition switch to ON 4.5 to 5.5 V
    B50-114 (VCE1) - B50-81 (E1) R - W-B Power source for VVT sensor (specific voltage) Ignition switch to ON 4.5 to 5.5 V
    B50-112 (VCE2) - B50-81 (E1) LG - W-B Power source for VVT sensor (specific voltage) Ignition switch to ON 4.5 to 5.5 V
    B50-113 (VCV2) - B50-81 (E1) R - W-B Power source for VVT sensor (specific voltage) Ignition switch to ON 4.5 to 5.5 V
    B50-75 (VCPP) - B50-76 (EPPM) R - G Power source for canister pressure sensor (specific voltage) Ignition switch to ON 4.5 to 5.5 V
    B50-63 (STAR)*2 - B50-81 (E1) R - W-B ST relay control Ignition switch to ON, shift lever position other then P or N 11 to 14 V
    A55-48 (STA) - B50-81 (E1) V - W-B ST relay operation signal Cranking 11 to 14 V
    A55-14 (STSW)*2 - B50-81 (E1) R - W-B ST relay operation signal Cranking 11 to 14 V
    B50-52 (OC2+) - B50-51 (OC2-) BR - R Camshaft timing Oil Control Valve (OCV) operation signal (Intake side) Idling Pulse generation
    (see waveform 1 found in Fig 2)
    B50-58 (OC1+) - B50-57 (OC1-) W - B Camshaft timing Oil Control Valve (OCV) operation signal (Intake side) Idling Pulse generation
    (see waveform 1 found in Fig 2)
    B50-67 (VV2+) - B50-90 (VV2-) W - B Variable Valve Timing (VVT) sensor signal (Intake side) Idling Pulse generation
    (see waveform 6 found in Fig 7)
    B50-69 (VV1+) - B50-92 (VV1-) L - LG Variable Valve Timing (VVT) sensor signal (Intake side) Idling Pulse generation
    (see waveform 6 found in Fig 7)
    B50-110 (NE+) - B50-111 (NE-) G - R Crankshaft position sensor signal Idling Pulse generation
    (see waveform 5 found in Fig 6 and waveform 6 found in Fig 7)
    B50-66 (EV2+) - B50-89 (EV2-) G-R - L Variable Valve Timing (VVT) sensor signal (Exhaust side) Idling Pulse generation
    (see waveform 5 found in Fig 6)
    B50-68 (EV1+) - B50-91 (EV1-) Y - B Variable Valve Timing (VVT) sensor signal (Exhaust side) Idling Pulse generation
    (see waveform 5 found in Fig 6)
    B50-16 (OE1+) - B50-17 (OE1-) L - LG Camshaft timing Oil Control Valve (OCV) operation signal (Exhaust side) Idling Pulse generation
    (see waveform 1 found in Fig 2)
    B50-14 (OE2+) - B50-15 (OE2-) W-L - Y Camshaft timing Oil Control Valve (OCV) operation signal (Exhaust side) Idling Pulse generation
    (see waveform 1 found in Fig 2)
    B50-48 (HT1B) - B50-81 (E1)
    B50-47 (HT2B) - B50-81 (E1)    		 LG - W-B
    Y - W-B    		 Heated oxygen sensor heater operation signal Idling Below 3.0 V
    B50-48 (HT1B) - B50-81 (E1)
    B50-47 (HT2B) - B50-81 (E1)    		 LG - W-B
    Y - W-B    		 Heated oxygen sensor heater operation signal Ignition switch to ON 11 to 14 V
    B50-42 (ACM) - B50-81 (E1) L-B - W-B VSV for active control mount system operation signal Ignition switch to ON 11 to 14 V
    B50-18 (M-) - B50-20 (ME01) R - B Throttle drive motor operation signal (negative terminal) Idling with warm engine Pulse generation
    (see waveform 11 found in Fig 12)
    B50-19 (M+) - B50-20 (ME01) G - B Throttle drive motor operation signal (positive terminal) Idling with warm engine Pulse generation
    (see waveform 10 found in Fig 11)
    B50-21 (E02) - Body ground B-W - - Earth (ground) circuit of ECM Always Below 1 Ω
    B50-22 (E01) - Body ground W-B - - Earth (ground) circuit of ECM Always Below 1 Ω
    B50-40 (IGT1) - B50-81 (E1)
    B50-39 (IGT2) - B50-81 (E1)
    B50-38 (IGT3) - B50-81 (E1)
    B50-37 (IGT4) - B50-81 (E1)
    B50-36 (IGT5) - B50-81 (E1)
    B50-35 (IGT6) - B50-81 (E1)    		 W - W-B
    G-R - W-B
    G - W-B
    LG - W-B
    P - W-B
    L-B - W-B    		 Ignition coil (ignition signal) Idling Pulse generation
    (see waveform 7 found in Fig 8)
    B50-41 (GE01) - B50-81 (E1) G-R - W-B Shielded earth (ground) circuit of throttle drive motor Always Below 1 Ω
    B50-88 (OX1B) - B50-65 (EX1B)
    B50-87 (OX2B) - B50-64 (EX2B)    		 W - BR
    B - W-B    		 Heated oxygen sensor signal Engine speed at 2500 rpm for 2 minutes after warming up Pulse generation
    (see waveform 2 found in Fig 3)
    B50-96 (VCTA) - B50-97 (ETA) B - P Power source for throttle position sensor (specific voltage) Idling with warm engine 4.5 to 5.5 V
    B50-99 (VTA2) - B50-97 (ETA) W-L - P Throttle position sensor signal (for sensor malfunction detection) Ignition switch to ON, Accelerator pedal fully released 2.1 to 3.1 V
    B50-99 (VTA2) - B50-97 (ETA) W-L - P Throttle position sensor signal (for sensor malfunction detection) Ignition switch to ON, Accelerator pedal fully depressed 4.6 to 5.0 V
    B50-98 (VTA1) - B50-97 (ETA) Y - P Throttle position sensor signal (for engine control) Ignition switch to ON, Accelerator pedal fully released 0.5 to 1.1 V
    B50-98 (VTA1) - B50-97 (ETA) Y - P Throttle position sensor signal (for engine control) Ignition switch to ON, Accelerator pedal fully depressed 3.2 to 4.8 V
    B50-79 (THW) - B50-78 (ETHW) B - B-W Engine coolant temperature sensor signal Idling, Engine coolant temperature 80°C (176°F) 0.2 to 1.0 V
    B50-71 (THA) - B50-74 (ETHA) P - G-R Intake air temperature sensor signal Idling, Intake air temperature 20°C (68°F) 0.5 to 3.4 V
    B50-106 (IGF1) - B50-81 (E1) BR - W-B Ignition coil (ignition confirmation signal) Ignition switch to ON 4.5 to 5.0 V
    B50-106 (IGF1) - B50-81 (E1) BR - W-B Ignition coil (ignition confirmation signal) Idling Pulse generation
    (see waveform 7 found in Fig 8)
    A55-4 (AICV) - B50-81 (E1) V - W-B VSV for air intake control system operation signal Ignition switch to ON 11 to 14 V
    B50-73 (E2G) - B50-81 (E1) LG - W-B Earth (ground) circuit of sensor for mass air flow meter Always Below 1 Ω
    B50-72 (VG) - B50-73 (E2G) L-B - LG Mass Air Flow (MAF) meter signal Idling, Shift lever position P or N, A/C switch OFF 0.5 to 3.0 V
    B50-107 (ACIS) - B50-81(E1) B-W - W-B Actuator for ACIS (Acoustic Control Induction System) operation signal Ignition switch to ON 11 to 14 V
    B50-108 (PRG) - B50-81 (E1) W - W-B Purge VSV for EVAP system operation signal Ignition switch to ON 11 to 14 V
    B50-108 (PRG) - B50-81 (E1) W - W-B Purge VSV for EVAP system operation signal Idling, under purge control Pulse generation
    (see waveform 8 found in Fig 9)
    B50-109 (HA2A) - B50-46 (E05) B-W - W A/F sensor heater operation signal Idling Below 3.0 V
    B50-109 (HA2A) - B50-46 (E05) B-W - W A/F sensor heater operation signal Ignition switch to ON 11 to 14 V
    B50-86 (HA1A) - B50-23 (E04) G - W A/F sensor heater operation signal Idling Below 3.0 V
    B50-86 (HA1A) - B50-23 (E04) G - W A/F sensor heater operation signal Ignition switch to ON 11 to 14 V
    B50-20 (ME01) - B50-81 (E1) B - W-B Earth (ground) circuit of ECM Always Below 1 Ω
    B50-104 (E03) - B50-81 (E1) B - W-B Earth (ground) circuit of ECM Always Below 1 Ω
    B50-46 (E05) - B50-81 (E1) W - W-B Earth (ground) circuit of ECM Always Below 1 Ω
    B50-23 (E04) - B50-81 (E1) W - W-B Earth (ground) circuit of ECM Always Below 1 Ω
    B50-62 (NSW) - B50-81 (E1) L-B - W-B Park/Neutral position switch signal Ignition switch to ON, Shift lever position P or N Below 3.0 V
    B50-62 (NSW) - B50-81 (E1) L-B - W-B Park/Neutral position switch signal Ignition switch to ON, Shift lever position other than P or N 11 to 14 V
    B50-118 (KNK2) - B50-117 (EKN2) B - W Knock sensor signal Engine speed at 4000 rpm after warming up Pulse generation
    (see waveform 4 found in Fig 5)
    B50-93 (A1A+) - B50-81 (E1) L - W-B A/F sensor signal Ignition switch to ON 3.3 V*1
    B50-120 (A2A+) - B50-81 (E1) BR - W-B A/F sensor signal Ignition switch to ON 3.3 V*1
    B50-95 (KNK1) - B50-94 (EKNK) R - G Knock sensor signal Engine speed at 4000 rpm after warming up Pulse generation
    (see waveform 4 found in Fig 5)
    B50-116 (A1A-) - B50-81 (E1) P - W-B A/F sensor Ignition switch to ON 2.9 V*1
    B50-119 (A2A-) - B50-81 (E1) Y - W-B A/F sensor Ignition switch to ON 2.9 V*1

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

    *2: w/ Smart Key System

    1. WAVEFORM 1
      Fig 2: Identifying Waveform 1
      GTY179226Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Camshaft timing Oil Control Valve (OCV) operation signal
        ECM Terminal Names Between OC1+ and OC1-, OC2+ and OC2-, OE1+ and OE1-, or OE2+ and OE2-
        Tester Ranges 5 V/DIV, 1 ms./DIV
        Conditions Idling
    2. WAVEFORM 2
      Fig 3: Identifying Waveform 2
      GTY286446Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Heated oxygen sensor signal
        ECM Terminal Names Between OX1B and EX1B, or OX2B and EX2B
        Tester Ranges 0.2 V/DIV, 200 ms./DIV
        Conditions Engine speed at 2500 rpm for 2 minutes after warming up

        HINT: 

        In the Data List, item O2S B1S2 and O2S B2S2 shows the ECM values from the heated oxygen sensor.

    3. WAVEFORM 3
      Fig 4: Identifying Waveform 3
      GTY315826Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Fuel injector assembly operation signal
        ECM Terminal Names Between #10 (to #60) and E01
        Tester Ranges 20 V/DIV, 20 ms./DIV
        Conditions Idling

        HINT: 

        The wavelength becomes shorter as the engine speed increases.

    4. WAVEFORM 4
      Fig 5: Identifying Waveform 4
      GTY143366Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Knock sensor signal
        ECM Terminal Names Between KNK1 and EKNK, or KNK2 and EKN2
        Tester Ranges 1 V/DIV, 1 ms./DIV
        Conditions Engine speed at 4000 rpm after warming up

        HINT: 

        • The wavelength becomes shorter as the engine speed increases.
        • The waveforms and amplitudes displayed differ slightly depending on the vehicle condition.
    5. WAVEFORM 5
      Fig 6: Identifying Waveform 5
      GTY297586Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Variable Valve Timing (VVT) sensor signal (1)
      2. Crankshaft position sensor signal (2)
        ECM Terminal Names (1) EV1+ and EV1-, or EV2+ and EV2-
        (2) Between NE+ and NE-
        Tester Ranges 5 V/DIV, 20 ms./DIV
        Conditions Idling

        HINT: 

        The wavelength becomes shorter as the engine speed increases.

    6. WAVEFORM 6
      Fig 7: Identifying Waveform 6
      GTY184605Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Variable Valve Timing (VVT) sensor signal (1)
      2. Crankshaft position sensor signal (2)
        ECM Terminal Names (1) Between VV1+ and VV1-, VV2+ and VV2-
        (2) Between NE+ and NE-
        Tester Ranges 5 V/DIV, 20 ms./DIV
        Conditions Idling

        HINT: 

        The wavelength becomes shorter as the engine speed increases.

    7. WAVEFORM 7
      Fig 8: Identifying Waveform 7
      GTY322440Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Igniter IGT signal (from ECM to igniter) (1)
      2. Igniter IGF signal (from igniter to ECM) (2)
        ECM Terminal Names (1) Between IGT (1 to 6) and E1
        (2) Between IGF1 and E1
        Tester Ranges 2 V/DIV, 20 ms./DIV
        Conditions Idling

        HINT: 

        The wavelength becomes shorter as the engine speed increases.

    8. WAVEFORM 8
      Fig 9: Identifying Waveform 8
      GTY317179Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Purge VSV for EVAP system operation signal
        ECM Terminal Names Between PRG and E1
        Tester Ranges 10 V/DIV, 20 ms./DIV
        Conditions Idling, under purge control

        HINT: 

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

    9. WAVEFORM 9
      Fig 10: Identifying Waveform 9
      GTY340521Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Vehicle speed signal
        ECM Terminal Names Between SPD and E1
        Tester Ranges 2 V/DIV, 20 ms./DIV
        Conditions Ignition switch to ON, Driving wheel rotated slowly

        HINT: 

        • The wavelength becomes shorter as the vehicle speed increases.
        • Depending on the vehicle, the output waveform voltage may rise to 12 V if influenced by optionally installed systems.
    10. WAVEFORM 10
      Fig 11: Identifying Waveform 10
      GTY290954Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Throttle actuator operation signal (positive terminal)
        ECM Terminal Names Between M+ and ME01
        Tester Ranges 5 V/DIV, 1 ms./DIV
        Conditions Idling with warm engine

        HINT: 

        The duty ratio varies depending on the throttle actuator operation.

    11. WAVEFORM 11
      Fig 12: Identifying Waveform 11
      GTY292199Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Throttle actuator operation signal (negative terminal)
        ECM Terminal Names Between M- and ME01
        Tester Ranges 5 V/DIV, 1 ms./DIV
        Conditions Idling with warm engine

        HINT: 

        The duty ratio varies depending on the throttle actuator operation.

    12. WAVEFORM 12
      Fig 13: Identifying Waveform 12
      GTY320620Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Engine speed signal
        ECM Terminal Names Between TACH and E1
        Tester Ranges 5 V/DIV, 10 ms./DIV
        Conditions Idling

        HINT: 

        The wavelength becomes shorter as the engine speed increases.

    13. WAVEFORM 13
      Fig 14: Identifying Waveform 13
      GTY320356Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. CAN Communication Signal (Reference)
        ECM Terminal Names Between CANL and E1
        Tester Ranges 1 V/DIV, 10 μs./DIV
        Conditions Idling switch to ON

        HINT: 

        The waveform varies depending on the CAN communication signal.

    14. WAVEFORM 14
      Fig 15: Identifying Waveform 14
      GTY317750Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. CAN Communication Signal (Reference)
        ECM Terminal Names Between CANH and E1
        Tester Ranges 1 V/DIV, 10 μs./DIV
        Conditions Idling switch to ON

        HINT: 

        The waveform varies depending on the CAN communication signal.

scientia non olet · About LEMON Manuals