ECD SYSTEM TERMINALS OF ECM
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. (Symbols)" 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. (Symbols) | Wiring Color | Terminal Description | Condition | Specified Condition |
|---|---|---|---|---|
| E39-23 (BATT) - E38-1 (E1) | G - W-B | Battery (for measuring battery voltage and for ECM memory) | Constant | 18 to 27 V |
| E40-24 (IGSW) - E38-1 (E1) | R - W-B | Ignition switch | Ignition switch ON | 18 to 27 V |
| E39-24 (+B) - E38-1 (E1) | Y - W-B | Power source of ECM | Ignition switch ON | 18 to 27 V |
| E40-25 (MREL) - E38-1 (E1) | W - W-B | ENG ECU relay operation signal | Ignition switch ON | 18 to 27 V |
| 15 seconds pass after ignition switch off | 0 to 2 V | |||
| E36-13 (VC) - E38-1 (E1) | L - W-B | Power source of sensor (specific voltage) | Ignition switch ON | 4.5 to 5.5 V |
| E35-13 (VC2) - E35-14 (E21) | L - P | Power source of fuel pressure sensor (for PCR2) | Ignition switch ON | 4.5 to 5.5 V |
| E36-19 (SREL)* - E38-1 (E1) | R-L - W-B | GLOW MAIN relay operation signal | Ignition switch ON, glow indicator light on | 18 to 27 V |
| Engine is warmed up: Idling | 0 to 2 V | |||
| E39-10 (GIND)* - E38-1 (E1) | R - W-B | Glow indicator | Ignition switch ON, glow indicator light on | 0 to 2 V |
| Engine is warmed up: Idling | 18 to 27 V | |||
| E39-2 (VPA) - E40-5 (EPA) | L - V | Accelerator pedal position sensor (for engine control) | Ignition switch ON, accelerator pedal fully released | 0.6 to 1.0 V |
| Ignition switch ON, accelerator pedal fully depressed | 2.8 to 3.6 V | |||
| E39-1 (VPA2) - E40-3 (EPA2) | G - R | Accelerator pedal position sensor (for sensor malfunction detection) | Ignition switch ON, accelerator pedal fully released | 1.4 to 1.8 V |
| Ignition switch ON, accelerator pedal fully depressed | 3.6 to 4.4 V | |||
| E40-6 (VCPA) - E40-5 (EPA) | GR - V | Power source of accelerator pedal position sensor (for VPA) | Ignition switch ON | 4.5 to 5.5 V |
| E40-4 (VCP2) - E40-3 (EPA2) | Y - R | Power source of accelerator pedal position sensor (for VPA2) | Ignition switch ON | 4.5 to 5.5 V |
| E35-17 (VG) - E35-18 (EVG) | G-Y - V | Mass air flow meter sub-assembly | Engine is warmed up: Idling | Pulse generation |
| E35-10 (THA) - E35-14 (E21) | W - P | Intake air temperature sensor (built into mass air flow meter sub-assembly) | Engine is warmed up: Idling, intake air temperature at 0 to 80°C (32 to 176°F) | 0.5 to 3.4 V |
| E35-8 (THIA) - E36-14 (E2) | Y-R - R | Intake air temperature sensor (after turbocharged) | Engine is warmed up: Idling, intake air temperature at 0 to 80°C (32 to 176°F) | 1.0 to 4.4 V |
| E35-9 (THW) - E36-14 (E2) | B - R | Engine coolant temperature sensor | Idling, engine coolant temperature at 80 to 120°C (176 to 248°F) | 0.2 to 0.6 V |
| E35-21 (#1) - E38-1 (E1) E35-22 (#2) - E38-1 (E1) E35-23 (#3) - E38-1 (E1) E35-24 (#4) - E38-1 (E1) |
B - W-B W - W-B R - W-B G - W-B |
Injector operation signal | Engine is warmed up: Idling | Pulse generation (See waveform 1) |
| E37-13 (G+) - E37-14 (G-) | R - G | Camshaft position sensor | Engine is warmed up: Idling | Pulse generation (See waveform 2) |
| E37-7 (NE+) - E37-8 (NE-) | B - W | Crankshaft position sensor | Engine is warmed up: Idling | Pulse generation (See waveform 2) |
| E39-8 (STP) - E38-1 (E1) | V - W-B | Stop light switch assembly | Ignition switch ON, brake pedal depressed | 18 to 27 V |
| Ignition switch ON, brake pedal released | 0 to 2 V | |||
| E39-9 (ST1-) - E38-1 (E1) | L - W-B | Stop light switch assembly (opposite to STP) | Ignition switch ON, brake pedal depressed | 0 to 2 V |
| Ignition switch ON, brake pedal released | 18 to 27 V | |||
| E40-23 (TC) - E38-1 (E1) | LG - W-B | Terminal TC of DLC3 | Ignition switch ON | 18 to 27 V |
| E39-6 (STA) - E38-1 (E1) | W - W-B | Starter signal | Cranking | 6 V or more |
| E39-19 (W) - E38-1 (E1) | GR - W-B | MIL | MIL illuminated | 0 to 2 V |
| Ignition switch ON, MIL not illuminated | 18 to 27 V | |||
| E39-7 (SP1) - E38-1 (E1) | L - W-B | Speed signal from combination meter assembly | Ignition switch ON, drive wheel slowly rotated (20 km/ h) | Pulse generation (See waveform 3) |
| E36-5 (PIM) - E36-14 (E2) | P - R | Manifold absolute pressure sensor | Vacuum of 40 kPa (300 mmHg) is applied | 0.1 to 0.7 V |
| Atmospheric pressure | 0.8 to 1.5 V | |||
| Pressure of 70 kPa (0.7 kgf/cm2) is applied | 1.6 to 2.3 V | |||
| E36-20 (IREL) - E38-1 (E1) | BR - W-B | EDU relay operation signal | Ignition switch ON → off | 0 to 2 V → 18 to 27 V (for a few seconds) |
| E35-16 (PCR1) - E36-14 (E2) | L-W - R | Fuel pressure sensor (main) | Idling (Approximately 30 MPa (306 kgf/cm2, 4351 psi)) |
1.6 to 2.0 V |
| E35-2 (PCR2) - E35-14 (E21) | B - P | Fuel pressure sensor (sub) | Idling (Approximately 30 MPa (306 kgf/cm2, 4351 psi)) |
1.1 to 1.5 V |
| E35-4 (THF) - E36-14 (E2) | Y - R | Fuel temperature sensor (built into injection or supply pump assembly) | Ignition switch ON (with cold engine) |
1.6 to 2.0 V |
| E37-15 (VCG) - E37-14 (G-) | L-R - G | Power source of camshaft position sensor | Ignition switch ON | 4.5 to 5.5 V |
| E37-23 (PCV+) - E37-12 (PCV-) | L - L-Y | Suction control valve (built into injection or supply pump assembly) | Idling | Pulse generation (See waveform 4) |
| E35-20 (INJF) - E38-1 (E1) | B - W-B | Injector driver assembly | Idling | Pulse generation (See waveform 5) |
| E36-3 (VLU) - E36-14 (E2) | Y-B - R | Throttle position sensor (built into diesel throttle body assembly) | Throttle valve fully closed | 0.4 to 1.0 V |
| Throttle valve fully open | 3.2 to 4.0 V | |||
| E37-16 (LUSL) - E38-1 (E1) | W - W-B | Throttle actuator (built into diesel throttle body assembly) duty signal | Accelerator pedal released → Accelerator pedal depressed (when throttle actuator is operating) | Pulse generation (See waveform 6) |
| E37-5 (THCO) - E35-14 (E21) | W-L - P | Exhaust gas temperature sensor (B1S2) | Engine is warmed up, idling | 2.5 to 4.5 V |
| E37-11 (THCI) - E35-14 (E21) | G - P | Exhaust gas temperature sensor (B1S1) | Engine is warmed up, idling | 2.5 to 4.5 V |
| E36-7 (PEX) - E35-14 (E21) | P-L - P | Differential pressure sensor assembly | Engine is warmed up, idling | 0.5 to 1.0 V |
| E39-14 (RGSW) - E38-1 (E1) | LG - W-B | DPF switch signal | DPF switch on | 18 to 27 V |
| DPF switch off | 0 to 2 V | |||
| E38-3 (EXB) - E38-1 (E1) | Y - W-B | Exhaust brake | Exhaust brake operating | 18 to 27 V |
| E39-22 (W2) - E38-1 (E1) | V - W-B | DPF indicator | DPF indicator on (ignition switch ON) | 0 to 2 V |
| DPF indicator off (idling) | 18 to 27 V | |||
| E37-21 (NUSW) - E38-1 (E1) | R - W-B | Exhaust brake neutral switch assembly | Ignition switch ON, shift position is neutral | 18 to 27 V |
| Ignition switch ON, shift position is not neutral | 0 to 2 V | |||
| E39-21 (CLSW) - E38-1 (E1) | L - W-B | Exhaust brake clutch switch (exhaust retarder switch assembly) | Clutch pedal depressed | 0 to 2 V |
| Clutch pedal released | 18 to 27 V | |||
| E36-12 (CAN+) - E38-1 (E1) | W - W-B | CAN communication line | Engine stopped, ignition switch ON | Pulse generation (See waveform 7) |
| E36-6 (CAN-) - E38-1 (E1) | B - W-B | CAN communication line | Engine stopped, ignition switch ON | Pulse generation (See waveform 8) |
| E40-7 (CANH) - E38-1 (E1) | R - W-B | CAN communication line | Engine stopped, ignition switch ON | Pulse generation (See waveform 7) |
| E40-1 (CANL) - E38-1 (E1) | G - W-B | CAN communication line | Engine stopped, ignition switch ON | Pulse generation (See waveform 8) |
| E40-8 (CANP) - E38-1 (E1) | L - W-B | CAN communication line | Engine stopped, ignition switch ON | Pulse generation (See waveform 7) |
| E40-2 (CANN) - E38-1 (E1) | G - W-B | CAN communication line | Engine stopped, ignition switch ON | Pulse generation (See waveform 8) |
| E36-18 (AC) - E38-1 (E1) | R - W-B | Air conditioning signal | Air conditioning on | 18 to 27 V |
| Air conditioning off | 0 to 2 V | |||
| E40-13 (ACT) - E38-1 (E1) | G - W-B | Air conditioning cut signal | Idling | 18 to 27 V |
| Air conditioning cut signal on | 0 to 2 V | |||
| E38-9 (STCR) - E38-1 (E1) | W - W-B | ST CUT relay signal | Idling | 18 to 27 V |
| Cranking | 0 to 2 V | |||
| E37-19 (OSW) - E38-1 (E1) | P-L - W-B | Oil pressure switch | Engine is warmed up, idling | 18 to 27 V |
| Ignition switch ON | 0 to 2 V | |||
| E37-26 (RSW) - E38-1 (E1) | R-B - W-B | Back up light switch | Back up light switch is ON | 18 to 27 V |
| Ignition switch ON, shift position is neutral | 0 to 2 V | |||
| E36-22 (WSW) - E38-1 (E1) | L - W-B | Fuel filter (water level warning switch) | Ignition switch ON, water is not detected | 18 to 27 V |
| Ignition switch ON, water is detected | 0 to 2 V | |||
| E40-32 (PTO) - E38-1 (E1) | R - W-B | PTO switch | PTO switch ON | 18 to 27 V |
| PTO switch OFF | 0 to 2 V | |||
| E40-27 (IDUP) - E38-1 (E1) | B - W-B | Optional connector (for idle up) | Idle up switch ON | 18 to 27 V |
| Idle up switch OFF | 0 to 2 V | |||
| E36-1 (VCP1) - E36-2 (EP1) | L-R - R-Y | Power source of PTO accelerator position sensor | Ignition switch ON | 4.5 to 5.5 V |
| E36-8 (VPA1) - E36-2 (EP1) | B - R-Y | PTO accelerator position sensor signal | PTO Accelerator fully closed | 0.7 to 1.0 V |
| PTO Accelerator fully open | 3.3 to 3.9 V | |||
| E38-1 (E1) - Body ground | W-B - Body ground | Ground circuit of ECM | Always | Below 1 Ω |
| E36-14 (E2) - Body ground | R - Body ground | Ground circuit of ECM | Always | Below 1 Ω |
| E35-14 (E21) - Body ground | P - Body ground | Ground circuit of ECM | Always | Below 1 Ω |
| E38-11 (E01) - Body ground | W-B - Body ground | Ground circuit of ECM | Always | Below 1 Ω |
| E38-12 (E02) - Body ground | W-B - Body ground | Ground circuit of ECM | Always | Below 1 Ω |
| E39-11 (EC) - Body ground | W-B - Body ground | Ground circuit of ECM | Always | Below 1 Ω |
*: w/ Glow Plug Assembly
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Waveform 1
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Injector Assembly No. 1 Injection Signal (A)
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Injector Assembly No. 3 Injection Signal (B)
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Injector Assembly No. 4 Injection Signal (C)
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Injector Assembly No. 2 Injection Signal (D)
Terminal No. (Symbols) (A) E35-21 (#1) - E38-1 (E1)
(B) E35-23 (#3) - E38-1 (E1)
(C) E35-24 (#4) - E38-1 (E1)
(D) E35-22 (#2) - E38-1 (E1)
Tool Setting 5 V/DIV., 20 ms./DIV. Condition Engine is warmed up: Idling Tech Tips
The waveform varies depending on the injector injection.
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Waveform 2
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Crankshaft Position Sensor Signal (A)
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Camshaft Position Sensor Signal (B)
Terminal No. (Symbols) (A) E37-7 (NE+) - E37-8 (NE-)
(B) E37-13 (G+) - E37-14 (G-)
Tool Setting 5 V/DIV., 20 ms./DIV. Condition Engine is warmed up: Idling Tech Tips
The waveform varies depending on the engine revolution.
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Waveform 3
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Vehicle Speed Signal
Terminal No. (Symbols) E39-7 (SP1) - E38-1 (E1) Tool Setting 2 V/DIV., 10 ms./DIV. Condition Ignition switch ON, driving wheel slowly rotated Tech Tips
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The wavelength becomes shorter as the vehicle speed increases.
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The voltage value differs depending on the device (tachograph, etc.) that is connected to the circuit. When the waveform is high, the voltage is 5 V or higher, and when the waveform is low, the voltage is 1 V or less.
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Waveform 4
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Suction Control Valve Signal
Terminal No. (Symbols) E37-23 (PCV+) - E37-12 (PCV-) Tool Setting 20 V/DIV., 5 ms./DIV. Condition Idling Tech Tips
The waveform varies depending on the suction control valve operation.
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Waveform 5
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Injector Injection Confirmation Signal
Terminal No. (Symbols) E35-20 (INJF) - E38-1 (E1) Tool Setting 2 V/DIV., 1 ms./DIV. Condition Idling Tech Tips
The waveform varies depending on the injector injection.
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Waveform 6
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Throttle Actuator Signal
Terminal No. (Symbols) E37-16 (LUSL) - E38-1 (E1) Tool Setting 1 V/DIV., 2 ms./DIV. Condition Accelerator pedal released →
Accelerator pedal depressed
(when throttle actuator is operating)
Tech Tips
The waveform varies depending on the throttle valve operation.
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Waveform 7
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CAN Communication Signal
Terminal No. (Symbols) E36-12 (CAN+) - E38-1 (E1)
E40-7 (CANH) - E38-1 (E1)
E40-8 (CANP) - E38-1 (E1)
Tool Setting 1 V/DIV., 10 μsec./DIV. Condition Engine stopped, ignition switch ON Tech Tips
The waveform varies depending on the CAN communication signal.
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Waveform 8
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CAN Communication Signal
Terminal No. (Symbols) E36-6 (CAN-) - E38-1 (E1)
E40-1 (CANL) - E38-1 (E1)
E40-2 (CANN) - E38-1 (E1)
Tool Setting 1 V/DIV., 10 μsec./DIV. Condition Engine stopped, ignition switch ON Tech Tips
The waveform varies depending on the CAN communication signal.
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