Terminals Of ECM
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.
| 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 (SeeFig 2 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, Transmission gear neutral, A/C switch OFF | 0.5 to 3.0 V |
| THA (C20-65) - ETHA (C20-88) | P - BE | 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 |
3.2 to 4.8 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 4.7 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 (SeeFig 3waveform 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 | 2.9 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 2500 rpm for 2 minutes after warming up sensor | Pulse generation (See Fig 4waveform 3) |
| #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 |
Fuel injector | Ignition switch ON | 11 to 14 V |
| Idling | Pulse generation (SeeFig 5 waveform 4) | |||
| KNK1 (C20-110) - EKNK (C20-111) | R - G | Knock sensor | Engine speed maintained at 4000 after warming up engine | Pulse generation (SeeFig 6 waveform 5) |
| G2+ (C20-99) - NE- (C20-121) | B - P | Camshaft position sensor | Idling | Pulse generation (See Fig 7waveform 6) |
| NE+ (C20-122) - NE- (C20-121) | L - P | Crankshaft position sensor | Idling | Pulse generation (See Fig 7waveform 6) |
| 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 BE - W G - W LG - W |
Ignition coil (ignition signal) | Idling | Pulse generation (See Fig 8waveform 7) |
| 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 Fig 8waveform 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 Fig 9waveform 8) | |||
| SPD (A21-8) - E1 (C20-104) | V - W | Speed signal from combination meter | Driving at 20 km/h (12 mph) | Pulse generation (SeeFig 10 waveform 9) |
| STA (A21-48) - E1 (C20-104) | BR - W | Starter signal | Cranking | 11 to 14 V |
| STAR (C20-52) - E1 (C20-104) | BE - W | Starter relay control | Ignition switch ON, Shift position P or N (for A/T), 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 Fig 11waveform 10) |
| M- (C20-41) - ME01 (C20-43) | R - BR | Throttle actuator | Idling with warm engine | Pulse generation (SeeFig 12 waveform 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 1.5 V |
| 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 (SeeFig 13 waveform 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 - BE | Power source for canister pressure sensor (specific voltage) | Ignition switch ON | 4.5 to 5.5 V |
| PPMP (C20-71) - EPPM (C20-94) | L - BE | 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) | BE - 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 (SeeFig 14 waveform 13) |
| CANL (A21-49) - E1 (C20-104) | W - W | CAN communication line | Ignition switch ON | Pulse generation (SeeFig 15 waveform 14) |
HINT:
*: The ECM terminal voltage is constant regardless of the output voltage from the sensor.
- WAVEFORM 1 CAMSHAFT TIMING OIL CONTROL VALVE (OCV)
ECM Terminal Names Between OC1+ and OC1- Tester Ranges 5 V/DIV, 1 msec./DIV Conditions Idling - WAVEFORM 2 AIR-FUEL RATIO SENSOR HEATER
ECM Terminal Names Between HA1A and E04 Tester Ranges 5 V/DIV, 10 msec./DIV Conditions Idling with warm engine HINT:
The wavelength varies in accordance with the engine operating condition.
- WAVEFORM 3 HEATED OXYGEN SENSOR
ECM Terminal Names Between OX1B and EX1B Tester Ranges 0.2 V/DIV, 200 msec./DIV Conditions Engine speed maintained at 2500 rpm for 2 minutes after warming up sensor HINT:
In DATA LIST, item O2S B1S2 shows the ECM input values from the heated oxygen sensor.
- WAVEFORM 4 FUEL INJECTOR NO. 1 (TO NO. 4) 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.
- WAVEFORM 5 KNOCK SENSOR
ECM Terminal Names Between KNK1 and EKNK Tester Ranges 500 mV/DIV, 1 msec./DIV Conditions Engine speed maintained at 4000 rpm after warming up engine HINT:
- The waveforms and amplitudes displayed differ slightly depending on the vehicle.
- WAVEFORM 6 CRANKSHAFT POSITION SENSOR AND CAMSHAFT POSITION SENSOR
ECM Terminal Names CH1: 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.
- WAVEFORM 7 IGNITER IGT SIGNAL (FROM ECM TO IGNITER) AND IGNITER IGF SIGNAL (FROM IGNITER TO ECM)
ECM Terminal Names Between IGT (1 to 4) and E1
Between IGF1 and E1Tester Ranges 2 V/DIV, 20 msec./DIV Conditions Idling HINT:
The wavelength becomes shorter as the engine rpm increases.
- WAVEFORM 8 PURGE VSV
ECM Terminal Names Between PRG and E01 Tester Ranges 10 V/DIV, 20 msec./DIV Conditions Idling, during purge control HINT:
If the waveform is not similar to the illustration, check the waveform again after idling for 10 minutes or more.
- WAVEFORM 9 VEHICLE SPEED SIGNAL
ECM Terminal Names Between SPD and E1 Tester Ranges 2 V/DIV, 20 msec./DIV Conditions Driving at 20 km/h (12 mph) HINT:
The wavelength becomes shorter as the vehicle speed increases.
- WAVEFORM 10 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.
- WAVEFORM 11 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.
- WAVEFORM 12 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.
- WAVEFORM 13 REFERENCE: CAN COMMUNICATION SIGNAL
ECM Terminal Names Between CANH and E1 Tester Ranges 1 V/DIV, 10 μsec./DIV. Conditions Engine stops and ignition switch ON HINT:
The waveform varies depending on the CAN communication signal.
- WAVEFORM 14 REFERENCE: CAN COMMUNICATION SIGNAL
ECM Terminal Names Between CANL and E1 Tester Ranges 1 V/DIV, 10 μsec./DIV. Conditions Engine stops and ignition switch ON HINT:
The waveform varies depending on the CAN communication signal.