The ECM constantly generates a 5 V power source voltage from the battery voltage supplied to the +B, +B2 (BATT) terminals to operate the microprocessor. The ECM also provides this power to the sensors through the VC output circuit.
When the VC circuit has a short circuit, the microprocessor in the ECM and sensors that are supplied power through the VC circuit are deactivated because power is not supplied from the VC circuit. When the system is in this condition, it will not start.
For the circuit diagram of the ECM power source refer to the ECM power source circuit.
VC Output Circuit
Check the fuses for circuits related to this system before performing the following inspection procedure.
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Check the communication between the GTS and ECM.
It can be checked using the "Engine" item of the Data List.
| Result | Proceed to |
|---|---|
| Communication is not possible | A |
| Communication is possible | B |
A
B
| *1 | No. 1 Engine Room Relay Block and Junction Block Assembly |
| *2 | EFI NO. 2 Fuse |
Turn the ignition switch to ON.
Measure the voltage according to the value(s) in the table below.
| Tester Connection | Switch Condition | Specified Condition |
|---|---|---|
| 1 (EFI NO. 2 fuse) - Body ground | Ignition switch ON | 11 to 14 V |
Check the fuse with it installed to the No. 1 engine room relay block and junction block assembly.
If the result is not as specified, since current is not flowing to the +B and +B2 terminals of the ECM, the system may not be started.
| Proceed to |
|---|
| OK |
| NG |
OK
NG
Disconnect the throttle body with motor assembly connector.
Turn the ignition switch to ON.
Turn the GTS on.
Check the communication between the GTS and ECM.
It can be checked using the "Engine" item of the Data List.
| Result | Proceed to |
|---|---|
| Communication is not possible | A |
| Communication is possible | B |
Perform "Inspection After Repair" after replacing the throttle body with motor assembly.
A
B
Disconnect the accelerator pedal sensor assembly connector.
Turn the ignition switch to ON.
Turn the GTS on.
Check the communication between the GTS and ECM.
It can be checked using the "Engine" item of the Data List.
| Result | Proceed to |
|---|---|
| Communication is not possible | A |
| Communication is possible | B |
A
B
Disconnect the crankshaft position sensor connector.
Turn the ignition switch to ON.
Turn the GTS on.
Check the communication between the GTS and ECM.
It can be checked using the "Engine" item of the Data List.
| Result | Proceed to |
|---|---|
| Communication is not possible | A |
| Communication is possible | B |
A
B
Disconnect the camshaft position sensor (for intake camshaft) connector.
Turn the ignition switch to ON.
Turn the GTS on.
Check the communication between the GTS and ECM.
It can be checked using the "Engine" item of the Data List.
| Result | Proceed to |
|---|---|
| Communication is not possible | A |
| Communication is possible | B |
A
B
Disconnect the manifold absolute pressure sensor connector.
Turn the ignition switch to ON.
Turn the GTS on.
Check the communication between the GTS and ECM.
It can be checked using the "Engine" item of the Data List.
| Result | Proceed to |
|---|---|
| Communication is not possible | A |
| Communication is possible | B |
A
B
Disconnect the camshaft position sensor (for exhaust camshaft) connector.
Turn the ignition switch to ON.
Turn the GTS on.
Check the communication between the GTS and ECM.
It can be checked using the "Engine" item of the Data List.
| Result | Proceed to |
|---|---|
| Communication is not possible | A |
| Communication is possible | B |
A
B
Disconnect the engine oil pressure and temperature sensor connector.
Turn the ignition switch to ON.
Turn the GTS on.
Check the communication between the GTS and ECM.
It can be checked using the "Engine" item of the Data List.
| Result | Proceed to |
|---|---|
| Communication is not possible | A |
| Communication is possible | B |
A
B
Disconnect the fuel pressure sensor (for high pressure side) connector.
Turn the ignition switch to ON.
Turn the GTS on.
Check the communication between the GTS and ECM.
It can be checked using the "Engine" item of the Data List.
| Result | Proceed to |
|---|---|
| Communication is not possible | A |
| Communication is possible | B |
Perform "Inspection After Repair" after replacing the fuel pressure sensor (for high pressure side).
A
B
Disconnect the fuel pressure sensor (for low pressure side) connector.
Turn the ignition switch to ON.
Turn the GTS on.
Check the communication between the GTS and ECM.
It can be checked using the "Engine" item of the Data List.
| Result | Proceed to |
|---|---|
| Communication is not possible | A |
| Communication is possible | B |
Perform "Inspection After Repair" after replacing the fuel pressure sensor (for low pressure side).
A
B
Disconnect the mass air flow meter sub-assembly connector.
Turn the ignition switch to ON.
Turn the GTS on.
Check the communication between the GTS and ECM.
It can be checked using the "Engine" item of the Data List.
| Result | Proceed to |
|---|---|
| Communication is not possible | A |
| Communication is possible | B |
Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly.
A
B
Disconnect the canister pump module connector.
Turn the ignition switch to ON.
Turn the GTS on.
Check the communication between the GTS and ECM.
It can be checked using the "Engine" item of the Data List.
| Result | Proceed to |
|---|---|
| Communication is not possible | A |
| Communication is possible | B |
A
B
Disconnect the differential pressure sensor connector.
Turn the ignition switch to ON.
Turn the GTS on.
Check the communication between the GTS and ECM.
It can be checked using the "Engine" item of the Data List.
| Result | Proceed to |
|---|---|
| Communication is not possible | A |
| Communication is possible | B |
A
B
Disconnect the shift stroke sensor connector.
Turn the ignition switch to ON.
Check the communication between the GTS and ECM.
It can be checked using the "Engine" item of the Data List.
| Result | Proceed to |
|---|---|
| Communication is not possible | A |
| Communication is possible | B |
A
B
for 2WD: Click hereDrivetrain>K121 (CVT)>SHIFT STROKE SENSOR>REMOVAL202409,999999,_52,_138176,_0579403,RM100000002NGJ7,
for AWD: Click hereDrivetrain>K121F (CVT)>SHIFT STROKE SENSOR>REMOVAL202409,999999,_52,_138817,_0584987,RM100000002NGKR,
Disconnect the oil pressure sensor connector.
Turn the ignition switch to ON.
Check the communication between the GTS and ECM.
It can be checked using the "Engine" item of the Data List.
| Result | Proceed to |
|---|---|
| Communication is not possible | A |
| Communication is possible | B |
A
B
for 2WD: Click hereDrivetrain>K121 (CVT)>OIL PRESSURE SENSOR>REMOVAL202304,999999,_52,_138176,_0579402,RM1000000029EMM,
for AWD: Click hereDrivetrain>K121F (CVT)>OIL PRESSURE SENSOR>REMOVAL202304,999999,_52,_138817,_0584986,RM1000000029IK9,
Disconnect the throttle body with motor assembly connector.
Disconnect the accelerator pedal sensor assembly connector.
Disconnect the crankshaft position sensor connector.
Disconnect the camshaft position sensor (for intake camshaft) connector.
Disconnect the camshaft position sensor (for exhaust camshaft) connector.
Disconnect the manifold absolute pressure sensor connector.
Disconnect the engine oil pressure and temperature sensor connector.
Disconnect the fuel pressure sensor (for high pressure side) connector.
Disconnect the fuel pressure sensor (for low pressure side) connector.
Disconnect the mass air flow meter sub-assembly connector.
Disconnect the canister pump module connector.
Disconnect the shift stroke sensor connector.
Disconnect the oil pressure sensor connector.
Disconnect the ECM connectors.
Disconnect the differential pressure sensor connector.
Measure the resistance according to the value(s) in the table below.
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| C71-158 (VCTA) - Body ground | Always | 10 kΩ or higher |
| C71-129 (VCNE) - Body ground | Always | 10 kΩ or higher |
| C71-160 (VCV1) - Body ground | Always | 10 kΩ or higher |
| C71-130 (VCE1) - Body ground | Always | 10 kΩ or higher |
| C71-144 (VCPM) - Body ground | Always | 10 kΩ or higher |
| C71-146 (VCPE) - Body ground | Always | 10 kΩ or higher |
| A116-87 (VCPA) - Body ground | Always | 10 kΩ or higher |
| A116-90 (VCP2) - Body ground | Always | 10 kΩ or higher |
| C71-137 (VCVG) - Body ground | Always | 10 kΩ or higher |
| C71-179 (VCPR) - Body ground | Always | 10 kΩ or higher |
| C71-147 (VCPF) - Body ground | Always | 10 kΩ or higher |
| A116-72 (VCPP) - Body ground | Always | 10 kΩ or higher |
| C71-128 (VSPE) - Body ground | Always | 10 kΩ or higher |
| C71-154 (VCSF) - Body ground | Always | 10 kΩ or higher |
| C71-121 (VCPT) - Body ground | Always | 10 kΩ or higher |
| A116-21 (+B) - 1 (EFI NO. 2 fuse) | Always | Below 1 Ω |
| A116-51 (+B2) - 1 (EFI NO. 2 fuse) | Always | Below 1 Ω |
| Proceed to |
|---|
| OK |
| NG |
OK
NG