ECD SYSTEM TERMINALS OF ECM

B0025LKE81

Tech Tips

Each ECM terminal's standard voltage is shown in the table below.

In the table, first follow the information under "Condition".

Look under "Terminal No. (Symbol)" for the terminals to be inspected. The standard voltage between the terminals is shown under "Specified Condition".

Use the illustration above as a reference for the ECM terminals.

Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
G121-2 (BATT) - C127-5 (E1) Y - BR Battery (for measuring the battery voltage and for the ECM memory) Always 11 to 14 V
G121-8 (SREL) - C127-5(E1) LG - BR GLOW relay Cranking 11 to 14 V
Idling (engine started and 600 sec. have passed) 0 to 1.5 V
G121-10 (MREL) - C127-5(E1) G - BR MAIN relay Ignition switch ON 11 to 14 V
Ignition switch off (2 sec. after ignition switch off) 0 to 1.5 V
G121-17 (TC) - C127-5 (E1) R - BR Terminal TC of DLC3 Ignition switch ON 11 to 14 V
G120-25 (SP1) - C127-5 (E1) V- -BR Speed signal from combination meter Ignition switch ON, slowlyrotate wheel

Pulse generation

(See waveform 1)
G120-6 (STA) - C127-5 (E1) GR - BR Starter signal Cranking 6 V or more
G121-1 (+B) - C127-5 (E1) L - BR Power source of ECM Ignition switch ON 11 to 14 V
G121-11 (IGSW) - C127-5(E1) GR - BR Ignition switch Ignition switch ON 11 to 14 V
G120-9 (STP) - C127-5 (E1) L - BR Stop light switch Brake pedal depressed 11 to 14 V
Brake pedal released Below 1.5 V
G120-34(AC1) - C127-5 (E1) GR - BR A/C amplifier

A/C switch on

(magnetic clutch on)

 Below 1.5 V
A/C switch off 7.5 to 14 V
G121-9 (ACT) - C127-5 (E1) LG - BR A/C amplifier Ignition switch ON 11 to 14 V
A/C cut performed (driving below 30 km/h (18.6 mph), accelerator pedal fully depressed for 5 sec.) 0 to 3 V
G121-20 (VPA) - G121-27(EPA) W - G Accelerator pedal position sensor (for engine control) Ignition switch ON, accelerator pedal released 0.6 to 1.0 V
Ignition switch ON, accelerator pedal depressed 3.0 to 4.6 V
G121-28 (VPA2) - G121-29(EPA2) GR - Y Accelerator pedal position sensor (for sensor malfunction detection) Ignition switch ON, accelerator pedal released 1.4 to 1.8 V
Ignition switch ON, accelerator pedal depressed 3.7 to 5.0 V
G121-26 (VCPA) - G121-27(EPA) LG - G Power source of accelerator pedal position sensor (for VPA) Ignition switch ON 4.5 to 5.0 V
G121-23 (VCP2) - G121-29(EPA2) R - Y Power source of accelerator pedal position sensor (for VPA2) Ignition switch ON 4.5 to 5.0 V
G120-7 (TACH) - C127-5(E1) V - BR Engine speed sensor Idling

Pulse generation

(See waveform 2)
G120-10 (ST1-) - C127-5(E1) GR - BR Stop light switch Brake pedal depressed 0 to 1.5 V
Brake pedal released 7.5 to 14 V
C128-33 (PIM) - C128-32(EPIM) L - GR Manifold absolute pressure sensor 60 kPa (450 mmHg, 17.7 in.Hg) vacuum applied 0.2 to 0.8 V
207 kPa (1550 mmHg, 61.0 in.Hg) vacuum applied 4.2 to 4.8 V
C128-22 (THA) - C128-30(ETHA) Y - R Intake air temperaturesensor Idling, air intake temp. 0°C (32°F) to 80°C (176°F) 0.5 to 3.4 V
C128-21 (THW) - C128-29(ETHW) R - B Engine coolant temperature sensor Idling, engine coolant temp. 60°C (140°F) to 120°C (248°F) 0.2 to 1.0 V
C128-23 (THF) - C128-31(ETHF) G - R Terminal TC of DLC3 Ignition switch ON 11 to 14 V
C127-29 (DATA) - C127-5(E1) Y - BR Injection pump Within 0.5 sec. after ignition switch ON Pulse generation
C127-28 (CLK) - C127-5 (E1) L - BR Injection pump Within 0.5 sec. after ignition switch ON Pulse generation
C128-15 (THOP) - C127-5(E1) GR - BR Throttle open switch Idling (engine warmed up) 11 to 14 V
Ignition switch ON (once within 5 sec.) 0 to 3 V
C127-14 (LU-B) - C127-7(E01) Y - W-B

Throttle control motor

(intake shutter)

 Racing (engine warmed up)

Pulse generation

(See waveform 3)
C127-15 (LU+B) - C127-7(E01) R - W-B

Throttle control motor

(intake shutter)

 Racing (engine warmed up)

Pulse generation

(See waveform 3)
C127-16 (LU-A) - C127-7(E01) W - W-B

Throttle control motor

(intake shutter)

 Racing (engine warmed up)

Pulse generation

(See waveform 3)
C127-17 (LU+A) - C127-7(E01) GR - W-B

Throttle control motor

(intake shutter)

 Racing (engine warmed up)

Pulse generation

(See waveform 3)
C127-11 (TCV) - C127-7(E01) R - W-B Timing control valve Ignition switch ON 11 to 14 V
Idling

Pulse generation

(See waveform 4)
C127-2 (SPV+) - C127-5 (E1) L - BR Spill control valve Ignition switch ON 11 to 14 V
Idling Pulse generation
C127-1 (SPV-) - C127-5 (E1) Y - BR Spill control valve Idling

Pulse generation

(See waveform 5)
C128-26 (TDC+) - C128-34(TDC-) R - G Crankshaft position sensor Idling

Pulse generation

(See waveform 6)
C128-27 (NE+) - C128-35(NE-) L - Y Engine speed sensor Idling

Pulse generation

(See waveform 6)
G121-25 (CANH) - C127-5(E1) B - BR CAN communication line Ignition switch ON

Pulse generation

(See waveform 7)
G121-31 (CANL) - C127-5(E1) W - BR CAN communication line Ignition switch ON

Pulse generation

(See waveform 8)

  1. Waveform 1


    1. B0028VQE05
      *a 2 V/DIV.
      *b 20 msec./DIV.

      Speed signal

      ECM TerminalName Between SP1 and E1
      Tester Range 2 V/DIV., 20 msec./DIV.
      Condition Driving at approx. 20 km/h (12.4 mph)

      Tech Tips


      • As vehicle speed increases, the wavelength becomes shorter.

      • As vehicle speed increases, the waveform's amplitude becomes greater.

  2. Waveform 2


    1. B0028GCE08
      *a 5 V/DIV.
      *b 20 msec./DIV.

      Engine speed signal

      ECM TerminalName Between TACH and E1
      Tester Range 5 V/DIV., 20 msec./DIV.
      Condition Idling after warming up

      Tech Tips

      As engine speed increases, the wavelength becomes shorter.

  3. Waveform 3


    1. B0027XCE03

      Throttle control motor signals

      ECM TerminalName

      Between LU+A and E01

      Between LU-A and E01

      Between LU+B and E01

      Between LU-B and E01
      Tester Range 10 V/DIV., 0.5 msec./DIV.
      Condition Engine racing

  4. Waveform 4


    1. B00246QE01
      *1 10 V/DIV.
      *2 20 msec./DIV.

      Timing control value signal

      ECM TerminalName Between TCV and E01
      Tester Range 10 V/DIV., 20 msec./DIV.
      Condition During idling

  5. Waveform 5


    1. B0026AZE01
      *1 10 V/ DIV.
      *2 20 msec./DIV.

      Spill control valve signal

      ECM TerminalName Between SPV- and E1
      Tester Range 10 V/DIV., 20 msec./DIV.
      Condition During idling

  6. Waveform 6


    1. B0026CUE04
      *a 2 V/DIV.
      *b TDC
      *c 20 msec./DIV.

      Crankshaft position sensor and engine speed sensor signals

      ECM TerminalName

      Between TDC+ and TDC-

      Between NE+ and NE-
      Tester Range 2 V/DIV., 20 msec./DIV.
      Condition During idling

  7. Waveform 7


    1. B0028MAE01
      *a 1 V/DIV.
      *b 10 msec./DIV.

      CAN Communication Signal

      ECM TerminalName Between CANH and E1
      Tester Range 1 V/DIV., 10 msec./DIV.
      Condition Engine stopped, ignition switch ON

      Tech Tips

      The waveform varies depending on the CAN communication signal.

  8. Waveform 8


    1. B0025SFE01
      *a 1 V/DIV.
      *b 10 msec./DIV.

      CAN Communication Signal

      ECM TerminalName Between CANL and E1
      Tester Range 1 V/DIV., 10 msec./DIV.
      Condition Engine stopped, ignition switch ON

      Tech Tips

      The waveform varies depending on the CAN communication signal.