CHECK ECM
Measure the voltage of the ECM connectors.
Tech Tips
The standard 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 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.
Terminal No. (Symbol) | Wiring Color | Terminal Description | Condition | Specified Condition |
---|---|---|---|---|
G55-24 (BATT) - C36-12 (E1) | L - BR | Battery (for measuring battery voltage and for ECM memory) | Always | 11 to 14 V |
C36-23 (+BM) - C36-12 (E1) | GR - BR | Power source of throttle actuator | Always | 11 to 14 V |
G56-21 (IGSW) - C36-12 (E1) | W - BR | Ignition switch | Ignition switch ON | 11 to 14 V |
G55-22 (+B) - C36-12 (E1) | W - BR | Power source of ECM | Ignition switch ON | 11 to 14 V |
G55-23 (+B2) - C36-12 (E1) | W - BR | Power source of ECM | Ignition switch ON | 11 to 14 V |
C35-19 (OC1+) - C35-20 (OC1-) | G-Y - L-B | Camshaft timing oil control valve assembly (for Intake Side of Bank 1) | Ignition switch ON | Pulse generation (see waveform 1) |
C34-19 (OC2+) - C34-20 (OC2-) | L-W - L-R | Camshaft timing oil control valve assembly (for Intake Side of Bank 2) | Ignition switch ON | Pulse generation (see waveform 1) |
C35-21 (OE1+) - C35-22 (OE1-) | G-B - B-R | Camshaft timing oil control valve assembly (for Exhaust Side of Bank 1) | Ignition switch ON | Pulse generation (see waveform 1) |
C34-21 (OE2+) - C34-22 (OE2-) | W-G - L | Camshaft timing oil control valve assembly (for Exhaust Side of Bank 2) | Ignition switch ON | Pulse generation (see waveform 1) |
G55-9 (MREL) - C36-12 (E1) | V - BR | EFI relay | Ignition switch ON | 11 to 14 V |
C35-14 (VG) - C35-13 (E2G) | W-R - B-W | Mass air flow meter | Idling, shift lever in P or N, A/C switch off | 0.5 to 3.0 V |
C35-15 (THA) - C35-7 (ETHA) | Y-B - W-R | Intake air temperature sensor | Idling, intake air temperature 20°C (68°F) | 0.5 to 3.4 V |
C36-17 (THW) - C35-8 (ETHW) | R-L - W-R | Engine coolant temperature sensor | Idling, engine coolant temperature 80°C (176°F) | 0.2 to 1.0 V |
C36-13 (VCTA) - C36-14 (ETA) | L - W | Power source for throttle position sensor (fixed voltage) | Ignition switch ON | 4.5 to 5.5 V |
C36-15 (VTA1) - C36-14 (ETA) | LG - W | 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 | |||
C36-16 (VTA2) - C36-14 (ETA) | G-W - W | 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 | |||
G56-6 (VPA) - G56-3 (EPA) | L - P | 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 | |||
G56-5 (VPA2) - G56-1 (EPA2) | GR - W | Accelerator pedal position sensor (for sensor malfunction 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 | |||
G56-4 (VCPA) - G56-3 (EPA) | LG - P | Power source of accelerator pedal position sensor (for VPA) | Ignition switch ON | 4.5 to 5.5 V |
G56-2 (VCP2) - G56-1 (EPA2) | R - W | Power source of accelerator pedal position sensor (for VPA2) | Ignition switch ON | 4.5 to 5.5 V |
C37-17 (HA1A) - C37-16 (E04) C37-19 (HA2A) - C37-16 (E04) |
R-L - W-B B-W - W-B |
Air fuel ratio sensor heater | Idling | Below 3.0 V |
Ignition switch ON | 11 to 14 V | |||
C36-1 (A1A+) - C36-12 (E1) | P -BR | Air fuel ratio sensor | Ignition switch ON | 3.3 V* |
C36-2 (A1A-) - C36-12 (E1) | L - BR | Air fuel ratio sensor | Ignition switch ON | 3.0 V* |
C36-7 (A2A+) - C36-12 (E1) | Y - BR | Air fuel ratio sensor | Ignition switch ON | 3.3 V* |
C36-8 (A2A-) - C36-12 (E1) | L - BR | Air fuel ratio sensor | Ignition switch ON | 3.0 V* |
C37-12 (HT1B) - C37-11 (E03) C37-13 (HT2B) - C37-11 (E03) |
L-R - W-B L - W-B |
Heated oxygen sensor heater | Idling | Below 3.0 V |
Ignition switch ON | 11 to 14 V | |||
C34-2 (OX1B) - C34-1 (EX1B) C34-4 (OX2B) - C34-3 (EX2B) |
B - L-W B - GR |
Heated oxygen sensor | Engine speed maintained at 2500 rpm for 2 minutes after warming up sensor | Pulse generation (see waveform 2) |
C37-6 (#10) - C37-14 (E01) C37-1 (#20) - C37-14 (E01) C37-7 (#30) - C37-14 (E01) C37-2 (#40) - C37-14 (E01) C37-8 (#50) - C37-14 (E01) C37-3 (#60) - C37-14 (E01) |
L - W-B B - W-B R - W-B G - W-B Y - W-B R-L - W-B |
Fuel injector assembly | Ignition switch ON | 11 to 14 V |
Idling | Pulse generation (see waveform 3) | |||
C35-11 (KNK1) - C35-12 (EKNK) C35-5 (KNK2) - C35-6 (EKN2) |
B - W G - R |
Knock sensor | Engine speed maintained at 4000 rpm after warming up engine | Pulse generation (see waveform 4) |
C34-15 (VCV1) - C36-12 (E1) | P-L - BR | Power source for sensor (specific voltage) | Ignition switch ON | 4.5 to 5.5 V |
C34-16 (VCV2) - C36-12 (E1) | LG-B - BR | Power source for sensor (specific voltage) | Ignition switch ON | 4.5 to 5.5 V |
C34-9 (VV1+) - C34-10 (VV1-) | R - G | VVT sensor (for Intake Side of Bank 1) | Idling | Pulse generation (see waveform 5) |
C34-12 (VV2+) - C34-11 (VV2-) | G - GR | VVT Sensor (for Intake Side of Bank 2) | Idling | Pulse generation (see waveform 5) |
C34-13 (EV1+) - C34-14 (EV1-) | W-R - R-B | VVT Sensor (for Exhaust Side of Bank 1) | Idling | Pulse generation (see waveform 6) |
C34-18 (EV2+) - C34-17 (EV2-) | L - P | VVT Sensor (for Exhaust Side of Bank 2) | Idling | Pulse generation (see waveform 6) |
C34-6 (NE+) - C34-5 (NE-) | B - W | Crankshaft position sensor | Idling | Pulse generation (see waveform 5) |
C36-24 (IGT1) - C36-12 (E1) C36-25 (IGT2) - C36-12 (E1) C36-26 (IGT3) - C36-12 (E1) C36-27 (IGT4) - C36-12 (E1) C36-28 (IGT5) - C36-12 (E1) C35-25 (IGT6) - C36-12 (E1) |
R-Y - BR R-L - BR G-B - BR G-W - BR GR - BR L - BR |
Ignition coil assembly (ignition signal) | Idling | Pulse generation (see waveform 7) |
C36-6 (IGF1) - C36-12 (E1) | G-R - BR | Ignition coil assembly (ignition confirmation signal) | Ignition switch ON | 4.5 to 5.5 V |
Idling | Pulse generation (see waveform 7) | |||
C36-18 (PRG) - C36-12 (E1) | P - BR | Purge VSV | Ignition switch ON | 11 to 14 V |
Idling | Pulse generation (see waveform 8) | |||
G55-18 (SPD) - C36-12 (E1) | R - BR | Vehicle speed signal from combination meter assembly | Driving at 20 km/h (12 mph) | Pulse generation (see waveform 9) |
G56-10 (STA) - C36-12 (E1) | W - BR | Starter signal | Cranking | 5.5 V or more |
C35-2 (NSW) - C36-12 (E1) | B - BR | Starter relay control | Ignition switch ON | Below 1.5 V |
Cranking | 6.0 V or more | |||
G56-18 (STP) - C36-12 (E1) | V - BR | Stop light switch | Brake pedal depressed | 7.5 to 14 V |
Brake pedal released | Below 1.5 V | |||
G55-8 (ST1-) - C36-12 (E1) | B - BR | Stop light switch (opposite to voltage at STP terminal) |
Ignition switch ON, Brake pedal depressed |
Below 1.5 V |
Ignition switch ON, Brake pedal released |
7.5 to 14 V | |||
C37-20 (M+) - C37-10 (ME01) | P - W-B | Throttle actuator | Idling with warm engine | Pulse generation (see waveform 10) |
C36-29 (M-) - C37-10 (ME01) | L - W-B | Throttle actuator | Idling with warm engine | Pulse generation (see waveform 11) |
G56-8 (FC) - C36-12 (E1) | G - BR | Fuel pump control | Idling | Below 1.5 V |
G55-3 (FPC) - C36-12 (E1) | G - BR | Fuel pump control | Ignition switch ON | Below 1.5 V |
G56-26 (DI) - C36-12 (E1) | GR - BR | Fuel pump control | Ignition switch ON | 0 to 3.0 V |
C35-16 (PSP) - C36-12 (E1) | V - BR | Power steering oil pressure sensor | Ignition switch ON | 0.5 to 4.5 V |
G55-1 (AIP) - C35-7 (ETHA) | V - W-R | Secondary air injection system pressure signal | Ignition switch ON | 3.0 to 3.6 V |
G55-2 (AIP2) - C35-7 (ETHA) | B - W-R | Secondary air injection system pressure signal | Ignition switch ON | 3.0 to 3.6 V |
C35-30 (AIDI) - C36-12 (E1) | G - BR | Air switching valve for secondary air injection system | Air injection system operates | Pulse generation (see waveform 12) |
C34-26 (AIRV) - C36-12 (E1) | P - BR | Air switching valve for secondary air injection system | Ignition switch ON | 11 to 14 V |
C35-23 (AIRP) - C36-12 (E1) | GR - BR | Air switching valve for secondary air injection system | Ignition switch ON | 11 to 14 V |
C36-21 (AIR1) - C36-12 (E1) | L - BR | Air switching valve for secondary air injection system | Ignition switch ON | 11 to 14 V |
C36-20 (HAI1) - C36-12 (E1) | W - BR | Air pump heater for secondary air injection system | AI heater operating | 11 to 14 V |
G55-13 (W) - C36-12 (E1) | V - BR | MIL | Ignition switch ON | Below 1.5 V |
Idling | 11 to 14 V | |||
G56-28 (TC) - C36-12 (E1) | V - BR | Terminal TC of DLC3 | Ignition switch ON | 11 to 14 V |
G56-29 (TACH) - C36-12 (E1) | P - BR | Engine speed | Idling | Pulse generation (see waveform 13) |
C35-28 (ALT) - C36-12 (E1) | L - BR | Generator | Ignition switch ON | 11 to 14 V |
G56-32 (CANH) - C36-12 (E1) | R - BR | CAN communication line | Ignition switch ON | Pulse generation (see waveform 14) |
G56-31 (CANL) - C36-12 (E1) | W - BR | CAN communication line | Ignition switch ON | Pulse generation (see waveform 15) |
G56-34 (CANP) - C36-12 (E1) | BR - BR | CAN communication line | Ignition switch ON | Pulse generation (see waveform 14) |
G56-33 (CANN) - C36-12 (E1) | GR - BR | CAN communication line | Ignition switch ON | Pulse generation (see waveform 15) |
Tech Tips
*: The ECM terminal voltage is constant regardless of the output voltage from the sensor.
Waveform 1
Symbol | Between OC1+ and OC1- Between OC2+ and OC2- Between OE1+ and OE1- Between OE2+ and OE2- |
Tester Range | 5 V/DIV., 1 msec./DIV. |
Condition | Idling |
Waveform 2
Symbol | Between OX1B and EX1B Between OX2B and EX2B |
Tester Range | 0.2 V/DIV., 200 msec./DIV. |
Condition | Engine speed maintained at 2500 rpm for 2 minutes after warming up sensor |
Tech Tips
In Data List, item O2S B1S2 and O2S B2S2 shows the ECM input values from the heated oxygen sensor.
Waveform 3
Symbol | Between #10 (to #60) and E01 |
Tester Range | 20 V/DIV., 20 msec./DIV. |
Condition | Idling |
Tech Tips
The wavelength becomes shorter as the engine speed increases.
Waveform 4
Symbol | Between KNK1 and EKNK Between KNK2 and EKN2 |
Tester Range | 1 V/DIV., 1 msec./DIV. |
Condition | Engine speed maintained at 4000 rpm after warming up engine |
Tech Tips
The wavelength becomes shorter as the engine speed increases.
The waveforms and amplitudes displayed differ slightly depending on the vehicle.
Waveform 5
Symbol | Between NE+ and NE- Between VV1+ and VV1- Between VV2+ and VV2- |
Tester Range | 5 V/DIV., 20 msec./DIV. |
Condition | Idling |
Tech Tips
The wavelength becomes shorter as the engine rpm increases.
Waveform 6
Symbol | Between NE+ and NE- Between EV1+ and EV1- Between EV2+ and EV2- |
Tester Range | 5 V/DIV., 20 msec./DIV. |
Condition | Idling |
Tech Tips
The wavelength becomes shorter as the engine rpm increases.
Waveform 7
Symbol | Between IGT (1 to 6) and E1 Between IGF1 and E1 |
Tester Range | 2 V/DIV., 20 msec./DIV. |
Condition | Idling |
Tech Tips
The wavelength becomes shorter as the engine rpm increases.
Waveform 8
Symbol | Between PRG and E1 |
Tester Range | 10 V/DIV., 20 msec./DIV. |
Condition | Idling |
Tech Tips
If the waveform is not similar to the illustration, check the waveform again after idling for 10 minutes or more.
Waveform 9
Symbol | Between SPD and E1 |
Tester Range | 2 V/DIV., 20 msec./DIV. |
Condition | Driving at 20 km/h (12 mph) |
Tech Tips
The wavelength becomes shorter as the vehicle speed increases.
Waveform 10
Symbol | Between M+ and ME01 |
Tester Range | 5 V/DIV., 1 msec./DIV. |
Condition | Idling with warm engine |
Tech Tips
The duty ratio varies depending on the throttle actuator operation.
Waveform 11
Symbol | Between M- and ME01 |
Tester Range | 5 V/DIV., 1 msec./DIV. |
Condition | Idling with warm engine |
Tech Tips
The duty ratio varies depending on the throttle actuator operation.
Waveform 12
Symbol | Between AIDI and E1 |
Tester Range | 5 V/DIV., 20 msec./DIV. |
Condition | Performing system check using intelligent tester (air injection check) |
Tech Tips
The wavelength changes when the air injection control driver detects malfunctions in the air injection system.
Waveform 13
Symbol | Between TACH and E1 |
Tester Range | 5 V/DIV., 10 msec./DIV. |
Condition | Idling |
Tech Tips
The wavelength becomes shorter as the engine speed increases.
Waveform 14
Symbol | Between CANH and E1 Between CANP and E1 |
Tester Range | 1 V/DIV., 10 μsec./DIV. |
Condition | Engine stopped and ignition switch ON |
Tech Tips
The waveform varies depending on the CAN communication signal.
Waveform 15
Symbol | Between CANL and E1 Between CANN and E1 |
Tester Range | 1 V/DIV., 10 μsec./DIV. |
Condition | Engine stopped and ignition switch ON |
Tech Tips
The waveform varies depending on the CAN communication signal.