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Terminals Of ECM

Fig 1: Identifying ECM Terminals
G04828018Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT:

The standard normal voltage between each pair of ECM terminals is shown in ECM TERMINALS VOLTAGE SPECIFICATION TABLE . The appropriate conditions for checking each pair of 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 Fig 1 above can be used as a reference to identify the ECM terminal locations.

ECM TERMINALS VOLTAGE SPECIFICATION TABLE

Symbols (Terminal No.) Wiring Colors Terminal Descriptions Conditions Specified Conditions
BATT (A21-20) - E1 (C20-104) Y - W Battery (for measuring battery voltage and for ECM memory) Always 11 to 14 V
+BM (A21-3) - ME01 (C20-43) GR - BR Power source of throttle actuator Always 11 to 14 V
IGSW (A21-28) - E1 (C20-104) R - W Ignition switch Ignition switch ON 11 to 14 V
+B (A21-2) - E1 (C20-104) B - W Power source of ECM Ignition switch ON 11 to 14 V
+B2 (A21-1) - E1 (C20-104) B - W Power source of ECM Ignition switch ON 11 to 14 V
OC1+ (C20-100) - OC1- (C20-123) BR - R Camshaft timing oil control valve (OCV) Idling Pulse generation (see WAVEFORM 1 )
MREL (A21-44) - E1 (C20-104) GR - W EFI relay Ignition switch ON 11 to 14 V
VG (C20-118) - E2G (C20-116) GR - LG Mass air flow meter Idling, Shift lever position P or N, A/C switch OFF 0.5 to 3.0 V
THA (C20-65) - ETHA (C20-88) P - O Intake air temperature sensor Idling, Intake air temperature 20°C (68°F) 0.5 to 3.4 V
THW (C20-97) - ETHW (C20-96) L - P Engine coolant temperature sensor Idling, Engine coolant temperature 80°C (176°F) 0.2 to 1.0 V
VCTA (C20-67) - ETA (C20-91) W - V Power source of throttle position sensor (specific voltage) Ignition switch ON 4.5 to 5.5 V
VTA1 (C20-115) - ETA (C20-91) Y - V Throttle position sensor (for engine control) Ignition switch ON, Throttle valve fully closed 0.5 to 1.1 V
Ignition switch ON, Throttle valve fully open 3.3 to 4.9 V
VTA2 (C20-114) - ETA (C20-91) GR - V Throttle position sensor (for sensor malfunction detection) Ignition switch ON, Throttle valve fully closed 2.1 to 3.1 V
Ignition switch ON, Throttle valve fully open 4.6 to 5.0 V
VPA (A21-55) - EPA (A21-59) R - G Accelerator pedal position sensor (for engine control) Ignition switch ON, Accelerator pedal released 0.5 to 1.1 V
Ignition switch ON, Accelerator pedal fully depressed 2.6 to 4.5 V
VPA2 (A21-56) - EPA2 (A21-60) L - BR Accelerator pedal position sensor (for sensor malfunctioning detection) Ignition switch ON, Accelerator pedal released 1.2 to 2.0 V
Ignition switch ON, Accelerator pedal fully depressed 3.4 to 5.0 V
VCPA (A21-57) - EPA (A21-59) B - G Power source of accelerator pedal position sensor (for VPA) Ignition switch ON 4.5 to 5.5 V
VCP2 (A21-58) - EPA2 (A21-60) W - BR Power source of accelerator pedal position sensor (for VPA2) Ignition switch ON 4.5 to 5.5 V
HA1A (C20-109) - E04 (C20-46) G - W-B A/F sensor heater Idling Below 3.0 V
Ignition switch ON 11 to 14 V
A1A+ (C20-112) - E1 (C20-104) V - W A/F sensor Ignition switch ON 3.3 V*
A1A - (C20-113) - E1 (C20-104) LG - W A/F sensor Ignition switch ON 3.0 V*
HT1B (C20-47) - E03 (C20-86) LG - W-B Heated oxygen sensor heater Idling Below 3.0 V
Ignition switch ON 11 to 14 V
0X1B (C20-64) - EX1B (C20-87) G - GR Heated oxygen sensor Engine speed maintained at 2,500 rpm for 2 minutes after warming up sensor Pulse generation (see WAVEFORM 2 )
#10 (C20-108) - E01 (C20-45)
#20 (C20-107) - E01 (C20-45)
#30 (C20-106) - E01 (C20-45)
#40 (C20-105) - E01 (C20-45)		 SB-BR
GR - BR
P - BR
L-BR		 Injector Ignition switch ON 11 to 14 V
Idling Pulse generation (see WAVEFORM 3 )
KNK1 (C20-110) - EKNK (C20-111) R - G Knock sensor Engine speed maintained at 4,000 after warming up engine Pulse generation (see WAVEFORM 4 )
G2+ (C20-99) - NE - (C20-121) B - P Camshaft position sensor Idling Pulse generation (see WAVEFORM 5 )
NE+ (C20-122) - NE - (C20-121) L - P Crankshaft position sensor Idling Pulse generation (see WAVEFORM 5 )
IGT1 (C20-85) - E1 (C20-104)
IGT2 (C20-84) - E1 (C20-104)
IGT3 (C20-83) - E1 (C20-104)
IGT4 (C20-82) - E1 (C20-104)		 W - W
O - W
G - W
LG - W		 Ignition coil (ignition signal) Idling Pulse generation (see WAVEFORM 6 )
IGF1 (C20-81) - E1 (C20-104) Y - W Ignition coil (ignition confirmation signal) Ignition switch ON 4.5 to 5.5 V
Idling Pulse generation (see WAVEFORM 6 )
PRG (C20-49) - E01 (C20-45) L - BR Purge VSV Ignition switch ON 11 to 14 V
Idling Pulse generation (see WAVEFORM 7 )
SPD (A21-8) - E1 (C20-104) V - W Speed signal from combination meter Driving at 12 mph (20 km/h) Pulse generation (see WAVEFORM 8 )
STA (A21-48) - E1 (C20-104) BR - W Starter signal Cranking 11 to 14 V
STAR (C20-52) - E1 (C20-104) O - W Starter relay control Ignition switch ON Below 1.5 V
Cranking 6.0 V or more
ACCR (A21-13) - E01 (C20-45) G - BR ACC (Accessory) relay control signal Cranking Below 1.5 V
STSW (A21-14) - E1 (C20-104) B - W Ignition switch signal Ignition switch START 6.0 V or more
STP (A21-36) - E1 (C20-104) G - W Stop light switch Brake pedal depressed 7.5 to 14 V
Brake pedal released Below 1.5 V
ST1- (A21-35) - E1 (C20-104) Y - W Stop light switch (opposite to STP terminal) Ignition switch ON, Brake pedal depressed Below 1.5 V
Ignition switch ON, Brake pedal released 7.5 to 14 V
M+ (C20-42) - ME01 (C20-43) G - BR Throttle actuator Idling with warm engine Pulse generation (see WAVEFORM 9 )
M - (C20-41) - ME01 (C20-43) R - BR Throttle actuator Idling with warm engine Pulse generation (see WAVEFORM 10 )
FC (A21-7) - E01 (C20-45) V-BR Fuel pump control Ignition switch ON 11 to 14 V
Idling Below 1.5 V
W (A21-24) - E1 (C20-104) B - W MIL Ignition switch ON Below 1.5 V
Idling 11 to 14 V
TC (A21-27) - E1 (C20-104) P - W Terminal TC of DLC 3 Ignition switch ON 11 to 14 V
TACH (A21-15) - E1 (C20-104) LG - W Engine speed Idling Pulse generation (see WAVEFORM 11 )
VPMP (A21-42) - E1 (C20-104) P - W Vent valve (built into canister pump module) Ignition switch ON 11 to 14 V
MPMP (A21-34) - E1 (C20-104) V - W Leak detection pump (built into canister pump module) Leak detection pump OFF Below 3 V
Leak detection pump ON 11 to 14 V
VCPP (C20-70) - EPPM (C20-94) V - O Power source for canister pressure sensor (specific voltage) Ignition switch ON 4.5 to 5.5 V
PPMP (C20-71) - EPPM (C20-94) L - O Canister pressure sensor (built into canister pump module) Ignition switch ON 3 to 3.6 V
ELS (A21-31) - E1 (C20-104) G - W Electric load Tail light switch ON 7.5 to 14 V
Tail light switch OFF Below 1.5 V
ELS3 (A21-33) - E1 (C20-104) V - W Electric load Defogger switch ON 7.5 to 14 V
Defogger switch OFF Below 1.5 V
FAN (A21-21) - E1 (C20-104) O - W Fan No. 1 relay Ignition switch ON 11 to 14 V
Idling with A/C ON, or high engine coolant temperature Below 1.5 V
FAN2 (A21-22) - E1 (C20-104) LG - W Fan No. 2 relay Idling with high engine coolant temperature Below 1.5 V
ALT (C20-50) - E1 (C20-104) P - W Generator Ignition switch ON 11 to 14 V
CANH (A21-41) - E1 (C20-104) L - W CAN communication line Ignition switch ON Pulse generation (see WAVEFORM 12 )
CANL (A21-49) - E1 (C20-104) W - W CAN communication line Ignition switch ON Pulse generation (see WAVEFORM 13 )

HINT:

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

  1. WAVEFORM 1 

    Camshaft timing oil control valve (OCV) 

    WAVEFORM REFERENCE - CAMSHAFT TIMING OIL CONTROL VALVE

    ECM Terminal Names Between OC1+ and OC1-
    Tester Ranges 5 V/DIV, 1 msec/DIV
    Conditions Idling
    Fig 2: Identifying Waveform Graph (Waveform 1)
    G04828019Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. WAVEFORM 2 

    Heated oxygen sensor 

    WAVEFORM REFERENCE - HEATED OXYGEN SENSOR

    ECM Terminal Names Between OX1B and EX1B
    Tester Ranges 0.2 V/DIV, 200 msec/DIV
    Conditions Engine speed maintained at 2,500 rpm for 2 minutes after warming up sensor

    HINT:

    In DATA LIST, item O2S B1 S2 shows the ECM input values from the heated oxygen sensor.

    Fig 3: Identifying Waveform Graph (Waveform 2)
    G04828020Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. WAVEFORM 3 

    Injector No. 1 (to No. 4) injection signal 

    WAVEFORM REFERENCE - INJECTOR INJECTION SIGNAL

    ECM Terminal Names Between #10 (to #40) and E01
    Tester Ranges 20 V/DIV, 20 msec/DIV
    Conditions Idling

    HINT:

    The wavelength becomes shorter as the engine rpm increases.

    Fig 4: Identifying Waveform Graph (Waveform 3)
    G04828021Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  4. WAVEFORM 4 

    Knock sensor 

    WAVEFORM REFERENCE - KNOCK SENSOR

    ECM Terminal Names Between KNK1 and EKNK1
    Tester Ranges 1 V/DIV, 1 msec/DIV
    Conditions Engine speed maintained at 4,000 rpm after warming up engine

    HINT:

    • The wavelength becomes shorter as the engine rpm increases.
    • The waveforms and amplitudes displayed differ slightly depending on the vehicle.
      Fig 5: Identifying Waveform Graph (Waveform 4)
      G04828022Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  5. WAVEFORM 5 

    Crankshaft position sensor and Camshaft position sensor 

    WAVEFORM REFERENCE - CRANKSHAFT POSITION SENSOR AND CAMSHAFT POSITION SENSOR

    ECM Terminal Names CM: Between G2+ and NE-
    CH2: Between NE+ and NE-
    Tester Ranges 5 V/DIV, 20 msec/DIV
    Conditions Idling

    HINT:

    The wavelength becomes shorter as the engine rpm increases.

    Fig 6: Identifying Waveform Graph (Waveform 5)
    G04828023Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  6. WAVEFORM 6 

    Igniter IGT signal (from ECM to igniter) and Igniter IGF signal (from igniter to ECM) 

    WAVEFORM REFERENCE - IGNITER IGT SIGNAL AND IGNITER IGF SIGNAL

    ECM Terminal Names Between IGT (1 to 4) and E1 Between IGF1 and E1
    Tester Ranges 2 V/DIV, 20 msec/DIV
    Conditions Idling

    HINT:

    The wavelength becomes shorter as the engine rpm increases.

    Fig 7: Identifying Waveform Graph (Waveform 6)
    G04828024Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  7. WAVEFORM 7 

    Purge VSV 

    WAVEFORM REFERENCE - PURGE VSV

    ECM Terminal Names Between PRG and E1
    Tester Ranges 5 V/DIV, 50 msec./DIV
    Conditions Idling

    HINT:

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

    Fig 8: Identifying Waveform Graph (Waveform 7)
    G04828025Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  8. WAVEFORM 8 

    Vehicle speed signal 

    WAVEFORM REFERENCE - VEHICLE SPEED SIGNAL

    ECM Terminal Names Between SPD and E1
    Tester Ranges 2 V/DIV, 20 msec./DIV
    Conditions Driving at 12 mph (20 km/h)

    HINT:

    The wavelength becomes shorter as the vehicle speed increases.

    Fig 9: Identifying Waveform Graph (Waveform 8)
    G04828026Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  9. WAVEFORM 9 

    Throttle actuator positive terminal 

    WAVEFORM REFERENCE - THROTTLE ACTUATOR POSITIVE TERMINAL

    ECM Terminal Names Between M+ and ME01
    Tester Ranges 5 V/DIV, 1 msec/DIV
    Conditions Idling with warm engine

    HINT:

    The duty ratio varies depending on the throttle actuator operation.

    Fig 10: Identifying Waveform Graph (Waveform 9)
    G04828027Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  10. WAVEFORM 10 

    Throttle actuator negative terminal 

    WAVEFORM REFERENCE - THROTTLE ACTUATOR NEGATIVE TERMINAL

    ECM Terminal Names Between M- and ME01
    Tester Ranges 5 V/DIV, 1 msec/DIV
    Conditions Idling with warm engine

    HINT:

    The duty ratio varies depending on the throttle actuator operation.

    Fig 11: Identifying Waveform Graph (Waveform 10)
    G04828028Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  11. WAVEFORM 11 

    Engine speed signal 

    WAVEFORM REFERENCE - ENGINE SPEED SIGNAL

    ECM Terminal Names Between TACH and E1
    Tester Ranges 5 V/DIV, 10 msec/DIV
    Conditions Idling

    HINT:

    The wavelength becomes shorter as the engine rpm increases.

    Fig 12: Identifying Waveform Graph (Waveform 11)
    G04828029Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  12. WAVEFORM 12 

    Reference: CAN communication signal 

    WAVEFORM REFERENCE - CAN COMMUNICATION SIGNAL

    ECM Terminal Names Between CANH and E1
    Tester Ranges 1 V/DIV, 10 us/DIV
    Conditions Engine stops and ignition switch ON

    HINT:

    The waveform varies depending on the CAN communication signal.

    Fig 13: Identifying Waveform Graph (Waveform 12)
    G04828030Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  13. WAVEFORM 13 

    Reference: CAN communication signal 

    WAVEFORM REFERENCE - CAN COMMUNICATION SIGNAL

    ECM Terminal Names Between CANL and E1
    Tester Ranges 1 V/DIV, 10 us/DIV
    Conditions Engine stops and ignition switch ON

    HINT:

    The waveform varies depending on the CAN communication signal.

    Fig 14: Identifying Waveform Graph (Waveform 13)
    G04828031Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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