DTC P274A-11: Transmission Fluid Temperature Sensor "C" Circuit Short To Ground: Notes

WARNING: This page is about a different variant/trim than selected.

1. -

Outline of diagnosis:

Short circuit or short to ground of ATF temperature sensor circuit

(1 trip detection logic)

Trouble symptom:

Normal driving

Wiring diagram:

Hybrid system Ref. to WIRING SYSTEM (CROSSTREK MODEL (HEV))>HYBRID ELECTRIC VEHICLE SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

CAUTION: Before performing diagnosis, refer to "CAUTION" in "General Description". Ref. to P-HEV HYBRID POWERTRAIN CONTROL (DIAGNOSTICS)>GENERAL DESCRIPTION>CAUTION .

Courtesy of SUBARU OF AMERICA, INC.

Courtesy of SUBARU OF AMERICA, INC.

CHECK CONNECTION CONDITION OF CONNECTOR (Hybrid vehicle control ECU assembly CONNECTOR) .
Check the connecting condition of connector (B605) in Hybrid vehicle control ECU assembly and check the relevant terminals for contact pressure, deformation and intrusion of water or foreign matter. Ref. to HYBRID ELECTRIC VEHICLE>HYBRID POWERTRAIN CONTROL MODULE .

Is there looseness at the connector connection, or any poor contact, deformation or intrusion of water or foreign matters at the relevant terminals?

Yes : Connect the connector securely. Or repair the poor contact of connector.

No : Go to 2.
CHECK CONNECTION CONDITION OF CONNECTOR (ATF temperature sensor CONNECTOR) .
Check the connecting condition of connector (T44) in ATF temperature sensor and check the relevant terminals for contact pressure, deformation and intrusion of water or foreign matters.

Is there looseness at the connector connection, or any poor contact, deformation or intrusion of water or foreign matters at the relevant terminals?

Yes : Connect the connector securely. Or repair the poor contact of connector.

No : Go to 3.
CHECK DATA MONITOR (OIL TEMPERATURE OF TRANSAXLE) .
1. Turn to IG ON.
2. Using the Subaru Select Monitor, display the following items in the [Data Monitor] of [P-HEV Hybrid Powertrain Control]. Ref. to P-HEV HYBRID POWERTRAIN CONTROL (DIAGNOSTICS)>DATA MONITOR .
  - Transaxle Oil Temperature
When [Transaxle Oil Temperature] is -40°C (-40°F), go to A.

When [Transaxle Oil Temperature] is 215°C (419°F), go to B.

When [Transaxle Oil Temperature] is the same as the actual temperature, go to C.

Yes :
1. Go to 4.
2. Go to 6.
3. Even if DTC is displayed, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.
NOTE: In this case, temporary poor contact of connector, or temporary open or short circuit of the Wire harness may be the cause.

No : -
CHECK Transmission assembly UNIT (ATF temperature sensor) .
1. Turn the ignition to OFF.
2. Disconnect ATF temperature sensor connector (T44).
3. Using a tester, measure the resistance between ATF temperature sensor terminals.
  Connector & terminal
  
  (T44) No. 1 - (T46) No. 6:
Is the resistance 1.393 - 75.8 kΩ?

Yes : Go to 5.

No : Replace Transmission assembly. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION (TH2A)>TRANSMISSION ASSEMBLY .
CHECK Hybrid vehicle control ECU assembly .
1. Connect the connector (T44) of ATF temperature sensor.
2. Using SST (diagnosis check wire), short between terminals of Hybrid vehicle control ECU assembly connector.
  Short-circuit terminals
  
  (B605) No. 22 - (B605) No. 23:
3. Turn to IG ON.
4. Using the Subaru Select Monitor, display the following items in the [Data Monitor] of [P-HEV Hybrid Powertrain Control]. Ref. to P-HEV HYBRID POWERTRAIN CONTROL (DIAGNOSTICS)>DATA MONITOR .
  - Transaxle Oil Temperature
Is Transaxle Oil Temperature 215°C (419°F)?

Yes : Repair or replace the Wire harness between Hybrid vehicle control ECU assembly connector and ATF temperature sensor connector.

No : Replace Hybrid vehicle control ECU assembly. Ref. to HYBRID ELECTRIC VEHICLE>HYBRID POWERTRAIN CONTROL MODULE .
CHECK Transmission assembly UNIT (ATF temperature sensor) .
1. Turn the ignition to OFF.
2. Disconnect ATF temperature sensor connector (T44).
3. Using a tester, measure the resistance between ATF temperature sensor terminals.
  Connector & terminal
  
  (T44) No. 1 - (T46) No. 6:
Is the resistance 1.393 - 75.8 kΩ?

Yes : Go to 7.

No : Replace Transmission assembly. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION (TH2A)>TRANSMISSION ASSEMBLY .
CHECK Wire harness AND CONNECTOR (ATF temperature sensor - Hybrid vehicle control ECU assembly) (OPEN CIRCUIT) .
1. Disconnect Hybrid vehicle control ECU assembly connector (B605).
2. Using a tester, measure the resistance between ATF temperature sensor connector and Hybrid vehicle control ECU assembly connector.
  Connector & terminal
  
  (T44) No. 1 - (B605) No. 23:
  
  (T44) No. 6 - (B605) No. 22:
Is the resistance less than 1 Ω?

Yes : Go to 8.

No : Repair or replace the Wire harness between Hybrid vehicle control ECU assembly connector and ATF temperature sensor connector.
CHECK Wire harness AND CONNECTOR (ATF temperature sensor - Hybrid vehicle control ECU assembly) (SHORTED TO GROUND AND SHORTED BETWEEN LINES) .
Using a tester, measure the resistance between terminals in Hybrid vehicle control ECU assembly connector, and between Hybrid vehicle control ECU assembly connector and chassis ground.

Connector & terminal

(B605) No. 22 - (B605) No. 1 - 34:

(B605) No. 22 - Chassis ground:

(B605) No. 23 - (B605) No. 1 - 34:

(B605) No. 23 - Chassis ground:

Is the resistance 10 kΩ or more?

Yes : Replace Hybrid vehicle control ECU assembly. Ref. to HYBRID ELECTRIC VEHICLE>HYBRID POWERTRAIN CONTROL MODULE .

No : Repair or replace the Wire harness between Hybrid vehicle control ECU assembly connector and ATF temperature sensor connector.