Toyota Corolla Cross: Transmission Fluid Temperature Sensor "C" Circuit Short to Ground (P274A11,P274A15)

DTC SUMMARY

MALFUNCTION DESCRIPTION

These DTCs are stored when the transmission fluid temperature sensor output is abnormal. The cause of this malfunction may be one of the following:

Motor generator control ECU (MG ECU) internal malfunction

• Motor generator control ECU (MG ECU) malfunction

Transmission fluid temperature sensor malfunction

• Internal transmission fluid temperature sensor malfunction
• Open or short in transmission fluid temperature sensor

Wire harness between the transmission fluid temperature sensor and motor generator control ECU (MG ECU)

• The connectors are not connected properly
• Foreign matter or water on the connector terminals
• Open or short in wire harness

DESCRIPTION

The resistance of the thermistor built into the transmission fluid temperature sensor changes in accordance with changes in the transmission fluid temperature. The lower the transmission fluid temperature, the higher the thermistor resistance. Conversely, the higher the transmission fluid temperature, the lower the resistance.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Warning Indicate	Note
P274A11	Transmission Fluid Temperature Sensor "C" Circuit Short to Ground	Short to ground in the transmission fluid temperature sensor circuit (1 trip detection logic)	Wire harness or connector Inverter with converter assembly Hybrid vehicle transaxle assembly (Transmission fluid temperature sensor)	Comes on	Master Warning: Comes on	SAE Code: P274C
P274A15	Transmission Fluid Temperature Sensor "C" Circuit Short to Auxiliary Battery or Open	Open or short to +B in the transmission fluid temperature sensor circuit (1 trip detection logic)	Wire harness or connector Inverter with converter assembly Hybrid vehicle transaxle assembly (Transmission fluid temperature sensor)	Comes on	Master Warning: Comes on	SAE Code: P274D

HINT:

After confirming that DTC P274A11 or P274A15 is output, use the GTS to check "Transaxle Oil Temperature" in the Data List.

Displayed Temperature	Malfunction
-40°C (-40°F)	Open circuit or short to +B
215°C (419°F)	Short to ground

MONITOR DESCRIPTION

If the motor generator control ECU detects a malfunction of the transmission fluid temperature sensor, it will illuminate the MIL and store a DTC.

MONITOR STRATEGY

Related DTCs	P274C (INF P274A11): Transmission Fluid Temperature Sensor "C" Circuit Low P274D (INF P274A15): Transmission Fluid Temperature Sensor "C" Circuit High
Required sensors/components	Transmission fluid temperature sensor
Frequency of operation	Continuous
Duration	TMC's intellectual property
MIL operation	1 driving cycle
Sequence of operation	None

TYPICAL ENABLING CONDITIONS

The monitor will run whenever the following DTCs are not stored	TMC's intellectual property
Other conditions belong to TMC's intellectual property	-

TYPICAL MALFUNCTION THRESHOLDS

TMC's intellectual property

-

COMPONENT OPERATING RANGE

Motor generator control ECU

DTC P274C (INF P274A11) is not detected DTC P274D (INF P274A15) is not detected

CONFIRMATION DRIVING PATTERN

HINT:

• After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.

  Click here

• When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.

  Click here

1. Connect the GTS to the DLC3.
2. Turn the ignition switch to ON and turn the GTS on.
3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
4. Turn the ignition switch off and wait for 2 minutes or more.
5. Turn the ignition switch to ON and turn the GTS on.
6. With ignition switch ON and wait for 5 seconds or more. [*1]
7. Enter the following menus: Powertrain / Motor Generator / Utility / All Readiness.
8. Check the DTC judgment result.

   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, perform the normal judgment procedure again.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

CAUTION:

Refer to the precautions before inspecting high voltage circuit.

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NOTICE:

• After the ignition switch is turned off, there may be a waiting time before disconnecting the negative (-) auxiliary battery terminal.

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• When disconnecting and reconnecting the auxiliary battery.

  HINT:

  When disconnecting and reconnecting the auxiliary battery, there is an automatic learning function that completes learning when the respective system is used.

  Click here

PROCEDURE

1.	CHECK CONNECTOR CONNECTION CONDITION (INVERTER WITH CONVERTER ASSEMBLY CONNECTOR)

Click here

Result	Proceed to
OK	A
NG (The connector is not connected securely.)	B
NG (The terminals are not making secure contact or are deformed, or water or foreign matter exists in the connector.)	C

B

CONNECT SECURELY

C

REPAIR OR REPLACE HARNESS OR CONNECTOR

A

2.	CHECK CONNECTOR CONNECTION CONDITION (TRANSMISSION FLUID TEMPERATURE SENSOR CONNECTOR)

(a) Check the connection condition of the transmission fluid temperature sensor connector and the contact pressure of each terminal. Check the terminals for deformation, and check the connector for water ingress and foreign matter. Click here OK: - The connector is connected securely. - The terminals are not deformed and are connected securely. - No water or foreign matter in the connector.

Result	Proceed to
OK	A
NG (The connector is not connected securely.)	B
NG (The terminals are not making secure contact or are deformed, or water or foreign matter exists in the connector.)	C

B

CONNECT SECURELY

C

REPAIR OR REPLACE HARNESS OR CONNECTOR

A

3.	READ VALUE USING GTS (TRANSAXLE OIL TEMPERATURE)

(a) Read the Data List.

Powertrain > Motor Generator > Data List

Tester Display
Transaxle Oil Temperature

Result	Proceed to
-40°C (-40°F)	A
Same as actual temperature	B

(b) Turn the ignition switch off.

B

REPAIR OR REPLACE HARNESS OR CONNECTOR

A

4.	INSPECT HYBRID VEHICLE TRANSAXLE ASSEMBLY (TRANSMISSION FLUID TEMPERATURE SENSOR)

(a) Disconnect the transmission fluid temperature sensor connector.

(b) Measure the resistance according to the value(s) in the table below. Standard Resistance: Tester Connection Condition Specified Condition C142-3 (TTA) - C142-13 (TTAG) Ignition switch off 1.3 to 94 kΩ

*a Component without harness connected (Transmission Fluid Temperature Sensor (Hybrid Vehicle Transaxle Assembly))

(c) Reconnect the transmission fluid temperature sensor connector.

NG

REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY

OK

5.	CHECK HARNESS AND CONNECTOR (TRANSMISSION FLUID TEMPERATURE SENSOR - INVERTER WITH CONVERTER ASSEMBLY)

(a) Disconnect the transmission fluid temperature sensor connector.

(b) Disconnect the inverter with converter assembly connector.

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

Standard Resistance (Check for Open):

Tester Connection	Condition	Specified Condition
C142-3 (TTA) - C140-17 (TTA)	Ignition switch off	Below 1 Ω
C142-13 (TTAG) - C140-11 (TTAG)	Ignition switch off	Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection	Condition	Specified Condition
C142-3 (TTA) or C140-17 (TTA) - Body ground and other terminals	Ignition switch off	10 kΩ or higher
C142-13 (TTAG) or C140-11 (TTAG) - Body ground and other terminals	Ignition switch off	10 kΩ or higher

(d) Reconnect the inverter with converter assembly connector.

(e) Reconnect the transmission fluid temperature sensor connector.

OK

REPLACE INVERTER WITH CONVERTER ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

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