K120 / K121 (CVT): K121 CONTINUOUSLY VARIABLE TRANSAXLE SYSTEM: P274512,P274514,P274531; Intermediate Shaft Speed Sensor "B" Circuit Short to Battery; 2023 - 2025 MY Corolla Corolla Hatchback [03/2023

Last Modified: 05-13-2024	6.11:8.1.0	Doc ID: RM100000002B35D
Model Year Start: 2023	Model: Corolla Hatchback	Prod Date Range: [03/2023 - ]
Title: K120 / K121 (CVT): K121 CONTINUOUSLY VARIABLE TRANSAXLE SYSTEM: P274512,P274514,P274531; Intermediate Shaft Speed Sensor "B" Circuit Short to Battery; 2023 - 2025 MY Corolla Corolla Hatchback [03/2023 - ]

DTC

P274512

Intermediate Shaft Speed Sensor "B" Circuit Short to Battery

DTC

P274514

Intermediate Shaft Speed Sensor "B" Circuit Short to Ground or Open

DTC

P274531

Intermediate Shaft Speed Sensor "B" No Signal

DESCRIPTION

The transmission revolution sensor (NC1) detects the intermediate shaft (C1 clutch) speed and sends it to the ECM.

The ECM determines if gear mode should be entered by comparing the transmission revolution sensor (NT) and (NC1) signals.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

DTC Output from

Priority

Note

P274512

Intermediate Shaft Speed Sensor "B" Circuit Short to Battery

The transmission revolution sensor (NC1) signal is normal but the transmission revolution sensor (NC1) output voltage is higher than 1.8 V for 4.5 seconds or more (1-trip detection logic).

Wire harness or connector
Transmission revolution sensor (NC1)
ECM
Transmission wire

Comes on

Engine

SAE Code:

P07C8

P274514

Intermediate Shaft Speed Sensor "B" Circuit Short to Ground or Open

The transmission revolution sensor (NC1) signal is normal but the transmission revolution sensor (NC1) output voltage is less than 0.2 V for 4.5 seconds or more (1-trip detection logic).

Wire harness or connector
Transmission revolution sensor (NC1)
ECM
Transmission wire

Comes on

Engine

SAE Code:

P07C7

P274531

Intermediate Shaft Speed Sensor "B" No Signal

Any of the following conditions are met and the SPD signal indicates 10 km/h (6 mph) or more and the transmission revolution sensor (NC1) signal indicates less than 300 rpm for 5 seconds or more (1-trip detection logic).

When driving in gear mode, the transmission revolution sensor (NT) signal indicates 350 rpm or more
When driving in belt mode with the S1 synchronizer engaged, the transmission revolution sensor (NSS) signal indicates 780 rpm or more

Wire harness or connector
Transmission revolution sensor (NC1)
ECM
Transmission wire

Comes on

Engine

SAE Code:

P2747

MONITOR DESCRIPTION

The ECM receives signals from the transmission revolution sensor (NC1) installed to the continuously variable transaxle and determines the intermediate shaft (C1 clutch) speed.

If the ECM detects no signal from the transmission revolution sensor (NC1) even while the vehicle is being driven, it will determine that in the transmission revolution sensor (NC1) is malfunctioning, illuminate the MIL and store a DTC.

MONITOR STRATEGY

Related DTCs	P07C7: Intermediate shaft speed sensor (for Gear Drive) (Transmission revolution sensor (NC1))/Range check (Low voltage) P07C8: Intermediate shaft speed sensor (for Gear Drive) (Transmission revolution sensor (NC1))/Range check (High voltage) P2747: Intermediate shaft speed sensor (for Gear Drive) (Transmission revolution sensor (NC1))/Verify pulse input
Required sensors/Components	Transmission revolution sensor (NC1) Transmission revolution sensor (NT) Transmission revolution sensor (NSS) Vehicle speed sensor
Frequency of operation	Continuous
Duration	P07C7, P07C8: 4.5 sec. P2747: 5 sec.
MIL operation	Immediate
Sequence of operation	None

TYPICAL ENABLING CONDITIONS

All

Battery voltage	8 V or more
Ignition switch	ON
Starter	OFF

P07C7, P07C8

Intermediate shaft speed sensor pulse input fail (P2747)

(Pending / MIL)

Not detected

P2747

Intermediate shaft speed sensor range check fail (P07C7, P07C8) (Pending / MIL)	Not detected
D range position switch	ON
R range position switch	OFF
Park position switch	OFF
Neutral position switch	OFF
Engine	Running
Pressure control solenoid circuit fail (P0962, P0963, P0966, P0967, P2826, P2827, P282F, P2830) (Pending + MIL)	Not detected
Torque converter clutch pressure control solenoid circuit fail (P2763, P2764) (Pending + MIL)	Not detected
Shift solenoid circuit fail (P08D2, P08D3, P08DB, P08DC, P099E, P099F) (Pending + MIL)	Not detected
Synchronizer	Engaged
Vehicle speed	10 km/h (6.22 mph) or more
One of the following conditions is met	Conditions 1 or 2
1. All of the following conditions are met	-
- Speed sensor monitor driving mode	Gear mode
- Turbine speed sensor revolution	350 rpm or more
2. All of the following conditions are met	-
- Speed sensor monitor driving mode	Belt mode
- Intermediate shaft speed sensor for belt drive revolution	780 rpm or more

One of the following conditions is met: Condition (A) or (B)

Condition (A)

ECT	20°C (68°F) or more
ECT sensor circuit fail (P0117, P0118) (Pending + MIL)	Not detected
All of the following conditions are met	2 sec. or more
- Park position switch	OFF
- Neutral position switch	OFF

Condition (B)

One of the following conditions is met	-
- ECT	Less than 20°C (68°F)
- ECT sensor circuit fail (P0117, P0118) (Pending + MIL)	Detected
All of the following conditions are met	30 sec. or more
- Park position switch	OFF
- Neutral position switch	OFF

TYPICAL MALFUNCTION THRESHOLDS

P07C7

Intermediate shaft speed sensor voltage

Less than 0.2 V

P07C8

Intermediate shaft speed sensor voltage

More than 1.8 V

P2747

Intermediate shaft speed sensor revolution

Less than 300 rpm

COMPONENT OPERATING RANGE

P07C7, P07C8

Intermediate shaft speed sensor voltage

0.2 V or more and 1.8 V or less

P2747

Intermediate shaft speed sensor revolution

300 rpm or more

CONFIRMATION DRIVING PATTERN

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

HINT:

After repairs have been completed, clear the DTCs and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.
When clearing the permanent DTCs, refer to the Clear Permanent DTC procedure.
Click here

Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the ignition switch off and wait for 2 minutes or more.
Perform the D Position Shift Test inspection in Road Test. [*1]
Click here

HINT:

[*1]: Normal judgment procedure.

The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.
Stop the vehicle.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
Input the DTC: P274512, P274514 or P274531.

Check the DTC judgment result.

GTS Display	Description
NORMAL	DTC judgment completed System normal
ABNORMAL	DTC judgment completed System abnormal
INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

HINT:

If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.
If the judgment result shows INCOMPLETE or N/A, perform the normal judgment procedure again.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

CAUTION:

Strictly observe posted speed limits, traffic laws and road conditions.
Do not drive the vehicle with the cable of the GTS contacting the pedals, shift lever or steering wheel.
Driving the vehicle with the cable of the GTS contacting these areas could impede vehicle control, resulting in a serious accident.

Do not operate the GTS while driving the vehicle.
Operating the GTS while driving the vehicle will prevent you from paying sufficient attention to vehicle surroundings, and could result in a serious accident.

NOTICE:

Perform the universal trip to clear permanent DTCs.
Click here
Perform registration and/or initialization when parts related to the continuously variable transaxle system are replaced.
Click here
Check that no DTCs are stored after performing initialization.
Click here

PROCEDURE

1.	READ VALUE USING GTS (NC1 SENSOR VOLTAGE)

(a) According to the display on the GTS, read the Data List.

Powertrain > Engine > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

NC1 Sensor Voltage

Transmission revolution sensor (NC1) output voltage

Min.: 0.000 V

Max.: 4.999 V

0.2 to 1.8 V: Engine idling (Vehicle stopped with shift lever in P or N)

Powertrain > Engine > Data List

Tester Display
NC1 Sensor Voltage

Result	Proceed to
The value of NC1 Sensor Voltage is between 0.2 and 1.8 V	A
None of the above conditions are met	B

GO TO STEP 5

2.	READ VALUE USING GTS (NC1 SENSOR SPEED)

(a) According to the display on the GTS, read the Data List.

Powertrain > Engine > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

NC1 Sensor Speed

Intermediate shaft (C1 clutch) speed (NC1)

Min.: 0 rpm

Max.: 65535 rpm

0 rpm: Vehicle stopped and synchronizer engaged

Status of Synchronize

Synchronizer status

OFF or ON

OFF: Synchronizer not engaged
ON: Synchronizer engaged

Powertrain > Engine > Data List

Tester Display
NC1 Sensor Speed
Status of Synchronize

Result	Proceed to
The value of NC1 Sensor Speed is 0 rpm	A
None of the above conditions are met	B

GO TO STEP 5

3.	READ VALUE USING GTS (NC1 SENSOR SPEED)

(a) According to the display on the GTS, read the Data List.

Powertrain > Engine > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

NT Sensor Speed

Input turbine speed (NT)

Min.: 0 rpm

Max.: 65535 rpm

Equal to NC1 Sensor Speed: Vehicle being driven in gear mode

NC1 Sensor Speed

Intermediate shaft (C1 clutch) speed (NC1)

Min.: 0 rpm

Max.: 65535 rpm

Equal to NT Sensor Speed: Vehicle being driven in gear mode

Shift Mode

Shift mode status

Gear Mode or Belt Mode

Powertrain > Engine > Data List

Tester Display
NT Sensor Speed
NC1 Sensor Speed
Shift Mode

Result	Proceed to
The value of NT Sensor Speed and NC1 Sensor Speed are the same	A
The value of NT Sensor Speed and NC1 Sensor Speed are different	B

GO TO STEP 5

4.	REPLACE ECM

HINT:

Click here

PERFORM REGISTRATION AND INITIALIZATION

for Registration: Click here

for Initialization: Click here

5.	CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM)

Pre-procedure1

(a) Disconnect the C61 transmission wire connector.

(b) Disconnect the A178 and C160 ECM connectors.

Procedure1

Standard Resistance:

Tester Connection	Condition	Specified Condition
C61-16 (NC1B) - C160-97 (NC1B)	Always	Below 1 Ω
C61-17 (NC1O) - C160-98 (NC1O)	Always	Below 1 Ω
A178-22 (E1) - Body ground	Always	Below 1 Ω
C61-16 (NC1B) or C160-97 (NC1B) - Body ground and other terminals	Always	10 kΩ or higher
C61-17 (NC1O) or C160-98 (NC1O) - Body ground and other terminals	Always	10 kΩ or higher

Post-procedure1

(d) Connect the A178 and C160 ECM connectors.

(e) Connect the C61 transmission wire connector.

REPAIR OR REPLACE HARNESS OR CONNECTOR (TRANSMISSION WIRE - ECM)

CHECK ECM

Pre-procedure1

(a) Disconnect the C61 transmission wire connector.

(b) Turn the ignition switch to ON.

Procedure1

Standard Voltage:

Tester Connection	Condition	Specified Condition
C61-16 (NC1B) - Body ground	Ignition switch ON	11 to 14 V

Post-procedure1

(d) Turn the ignition switch off.

(e) Connect the C61 transmission wire connector.

Pre-procedure2

(f) Disconnect the A178 and C160 ECM connectors.

Procedure2

(g) Measure the resistance according to the value(s) in the table below.

Component without harness connected

(ECM)

Standard Resistance:

Tester Connection	Condition	Specified Condition
98 (NC1O) - 22 (E1)	Always	99 to 101 Ω

Post-procedure2

(h) Connect the A178 and C160 ECM connectors.

GO TO STEP 8

7.	INSPECT TRANSMISSION WIRE

Pre-procedure1

(a) Disconnect the C61 transmission wire connector.

(b) Disconnect the transmission wire connector from the transmission revolution sensor (NC1).

HINT:

Click here

Procedure1

Standard Resistance:

Tester Connection	Condition	Specified Condition
1 (transmission revolution sensor side) - 16 (NC1B) (wire harness connector side)	Always	Below 1 Ω
2 (transmission revolution sensor side) - 17 (NC1O) (wire harness connector side)	Always	Below 1 Ω
1 (transmission revolution sensor side) or 16 (NC1B) (wire harness connector side) - All other terminals	Always	10 kΩ or higher
2 (transmission revolution sensor side) or 17 (NC1O) (wire harness connector side) - All other terminals	Always	10 kΩ or higher

Result:

Proceed to
OK
NG

*1	Transmission Wire
*a	Transmission Revolution Sensor Side
*b	Wire Harness Connector Side

Post-procedure1

(d) None

REPLACE TRANSMISSION REVOLUTION SENSOR (NC1)

REPLACE TRANSMISSION WIRE

8.	REPLACE ECM

HINT:

Click here

PERFORM REGISTRATION AND INITIALIZATION

for Registration: Click here

for Initialization: Click here