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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 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 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.

VOLTAGE SPECIFICATION

Symbol (Terminal No.) Wiring Color Terminal Description Condition Specified Condition
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  1waveform 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, Transmission gear neutral, 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 with warm engine Pulse generation (see  2waveform 2)
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
OX1B (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  3waveform 3)
#10 (C20-108) - E01 (C20-45) SB - BR Fuel injector Ignition switch ON 11 to 14 V
#20 (C20-107) - E01 (C20-45) GR - BR Idling Pulse generation (see  4waveform 4)
#30 (C20-106) - E01 (C20-45) P - BR
#40 (C20-105) - E01 (C20-45) L - BR
KNK1 (C20-110) - EKNK (C20-111) R - G Knock sensor Engine speed maintained at 4,000 after warming up engine Pulse generation (see  5waveform 5)
G2+ (C20-99) - NE- (C20-121) B - P Camshaft position sensor Idling Pulse generation (see  6waveform 6)
NE+ (C20-122) - NE- (C20-121) L - P Crankshaft position sensor Idling Pulse generation (see  6waveform 6)
IGT1 (C20-85) - E1 (C20-104) W - W Ignition coil (ignition signal) Idling Pulse generation (see  7waveform 7)
IGT2 (C20-84) - E1 (C20-104) O - W
IGT3 (C20-83) - E1 (C20-104) G - W
IGT4 (C20-82) - E1 (C20-104) LG - W
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  7waveform 7)
PRG (C20-49) - E01 (C20-45) L - BR Purge VSV Ignition switch ON 11 to 14 V
Idling, during purge control Pulse generation (see  8waveform 8)
SPD (A21-8) - E1 (C20-104) V - W Speed signal from combination meter Driving at 12 mph (20 km/h) Pulse generation (see  9waveform 9)
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, Shift position P or N (for ATT), Clutch pedal fully depressed (for M/T) 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 position 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  10waveform 10)
M- (C20-41) - ME01 (C20-43) R - BR Throttle actuator Idling with warm engine Pulse generation (see  11waveform 11)
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 (MIL goes on) Below 1.5V
Idling (MIL goes off) 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  12waveform 12)
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  13waveform 13)
CANL (A21-49) - E1 (C20-104) W - W CAN communication line Ignition switch ON Pulse generation (see  14waveform 14)
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 1 REFERENCE CHART

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

    Air-fuel ratio sensor heater 

    WAVEFORM 2 REFERENCE CHART

    ECM Terminal Names Between HA1A and E04
    Tester Ranges 5 V/DIV, 10 msec./DIV
    Conditions Idling with warm engine
    Fig 3: Identifying Waveform 2
    G05589037Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    HINT:

    The wavelength varies in accordance with the engine operating condition.

  3. WAVEFORM 3 

    Heated oxygen sensor 

    WAVEFORM 3 REFERENCE CHART

    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
    Fig 4: Identifying Waveform 3
    G04828020Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    HINT:

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

  4. WAVEFORM 4 

    Fuel injector No. 1 (to No. 4) injection signal 

    WAVEFORM 4 REFERENCE CHART

    ECM Terminal Names Between #10 (to #40) and E01
    Tester Ranges 20 V/DIV, 20 msec./DIV
    Conditions Idling
    Fig 5: Identifying Waveform 4
    G04828021Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    HINT:

    The wavelength becomes shorter as the engine rpm increases.

  5. WAVEFORM 5 

    Knock sensor 

    WAVEFORM 5 REFERENCE CHART

    ECM Terminal Names Between KNK1 and EKNK
    Tester Ranges 500 mV/DIV, 1 msec./DIV
    Conditions Engine speed maintained at 4,000 rpm after warming up engine
    Fig 6: Identifying Waveform 5
    G05589040Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    HINT:

    • The waveforms and amplitudes displayed differ slightly depending on the vehicle.
  6. WAVEFORM 6 

    Crankshaft position sensor and Camshaft position sensor 

    WAVEFORM 6 REFERENCE CHART

    ECM Terminal Names CH1: Between G2+ and NE-
    CH2: Between NE+ and NE-
    Tester Ranges 5 V/DIV, 20 msec./DIV
    Conditions Idling
    Fig 7: Identifying Waveform 6
    G04828023Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    HINT:

    The wavelength becomes shorter as the engine rpm increases.

  7. WAVEFORM 7 

    Igniter IGT signal (from ECM to igniter) and Igniter 

    IGF signal (from igniter to ECM) 

    WAVEFORM 7 REFERENCE CHART

    ECM Terminal Names Between IGT (1 to 4) and E1 Between
    IGF1 and E1
    Tester Ranges 2 V/DIV, 20 msec./DIV
    Conditions Idling
    Fig 8: Identifying Waveform 7
    G04828024Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    HINT:

    The wavelength becomes shorter as the engine rpm increases.

  8. WAVEFORM 8 

    Purge VSV 

    WAVEFORM 8 REFERENCE CHART

    ECM Terminal Names Between PRG and E01
    Tester Ranges 10 V/DIV, 20 msec./DIV
    Conditions Idling
    Fig 9: Identifying Waveform 8
    G05589043Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    HINT:

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

  9. WAVEFORM 9 

    Vehicle speed signal 

    WAVEFORM 9 REFERENCE CHART

    ECM Terminal Names Between SPD and E1
    Tester Ranges 2 V/DIV, 20 msec./DIV
    Conditions Driving at 12 mph (20 km/h)
    Fig 10: Identifying Waveform 9
    G04828026Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    HINT:

    The wavelength becomes shorter as the vehicle speed increases.

  10. WAVEFORM 10 

    Throttle actuator positive terminal 

    WAVEFORM 10 REFERENCE CHART

    ECM Terminal Names Between M+ and ME01
    Tester Ranges 5 V/DIV, 1 msec./DIV
    Conditions Idling with warm engine
    Fig 11: Identifying Waveform 10
    G04828027Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    HINT:

    The duty ratio varies depending on the throttle actuator operation.

  11. WAVEFORM 11 

    Throttle actuator negative terminal 

    WAVEFORM 11 REFERENCE CHART

    ECM Terminal Names Between M- and ME01
    Tester Ranges 5 V/DIV, 1 msec./DIV
    Conditions Idling with warm engine
    Fig 12: Waveform Graph 11
    G04828028Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    HINT:

    The duty ratio varies depending on the throttle actuator operation.

  12. WAVEFORM 12 

    Engine speed signal 

    WAVEFORM 12 REFERENCE CHART

    ECM Terminal Names Between TACH and El
    Tester Ranges 5 V/DIV, 10 msec./DIV
    Conditions Idling
    Fig 13: Identifying Waveform 12
    G04828029Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    HINT:

    The wavelength becomes shorter as the engine rpm increases.

  13. WAVEFORM 13 

    Reference: CAN communication signal 

    WAVEFORM REFERENCE CHART

    ECM Terminal Names Between CANH and E1
    Tester Ranges 1 V/DIV, 10 μs/DIV
    Conditions Engine stops and ignition switch ON
    Fig 14: Identifying Waveform 13
    G04828030Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    HINT:

    The waveform varies depending on the CAN communication signal.

  14. WAVEFORM 14 

    Reference: CAN communication signal 

    WAVEFORM REFERENCE CHART

    ECM Terminal Names Between CANL and E1
    Tester Ranges 1 V/DIV, 10 μs/DIV
    Conditions Engine stops and ignition switch ON
    Fig 15: Identifying Waveform 14
    G04828031Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    HINT:

    The waveform varies depending on the CAN communication signal.

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