AUTOMATIC TRANSAXLE SYSTEM, Diagnostic DTC:P079112, P079114, P079131

DTC Code DTC Name
P079112 Intermediate Shaft Speed Sensor "A" Circuit Short to Battery
P079114 Intermediate Shaft Speed Sensor "A" Circuit Short to Ground or Open
P079131 Intermediate Shaft Speed Sensor "A" No Signal

DESCRIPTION

The transmission revolution sensor (NC) detects the rotation speed of the counter gear which shows the output shaft speed of automatic transaxle assembly.

Based on the transmission revolution sensor (NC) signal and the transmission revolution sensor (NT) signal, the ECM controls engine torque and shift timing.

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory Note
P079112 Intermediate Shaft Speed Sensor "A" Circuit Short to Battery

1. Diagnosis Condition 2. Malfunction Status 3. Malfunction Time 4. Other


  1. The battery voltage is 8 V or more, the ignition switch is ON and the starter is off.

  2. Transmission revolution sensor (NC) input signal voltage is more than 1.9 V

  3. 2 seconds

  4. 1-trip detection logic

  • Transmission revolution sensor (NC)

  • Transmission wire

  • Harness and connector

  • ECM

 Comes on DTC stored

SAE Code

P07C6
P079114 Intermediate Shaft Speed Sensor "A" Circuit Short to Ground or Open

1. Diagnosis Condition 2. Malfunction Status 3. Malfunction Time 4. Other


  1. The battery voltage is 8 V or more, the ignition switch is ON and the starter is off.

  2. Transmission revolution sensor (NC) input signal voltage is less than 0.1 V

  3. 2 seconds

  4. 1-trip detection logic

  • Transmission revolution sensor (NC)

  • Transmission wire

  • Harness and connector

  • ECM

 Comes on DTC stored

SAE Code

P07C5
P079131 Intermediate Shaft Speed Sensor "A" No Signal

1. Diagnosis Condition 2. Malfunction Status 3. Malfunction Time 4. Other


  1. All of the following conditions are met:


    1. The battery voltage is 8 V or more.

    2. Park/neutral position switch D input signal is ON

    3. The vehicle speed is 25 km/h (16 mph) or more.

    4. Speed indicated by transmission revolution sensor (NT) is higher than specified value

  2. Speed indicated by transmission revolution sensor (NC) is less than 300 rpm

  3. 2 seconds

  4. 1-trip detection logic

  • Transmission revolution sensor (NC)

  • Transmission wire

  • Harness and connector

  • ECM

 Comes on DTC stored

SAE Code

P0793

MONITOR DESCRIPTION

The transmission revolution sensor (NC) monitors the output shaft speed.

The ECM commands gear changes and controls the lock up timing based on the signals from the transmission revolution sensor (NC) and throttle position sensor.

If the vehicle is being driven at 25 km/h (16 mph) or more and the speed sensor (NC) signal sent to the ECM is less than 300 rpm, or if the transmission revolution sensor (NC) input signal voltage is less than 0.1 V or more than 1.9 V, the ECM will illuminate the MIL and store a DTC.

WIRING DIAGRAM

B004095E18
*a Transmission Revolution Sensor (NC)
*b Transmission Wire

CAUTION / NOTICE / HINT

Note

Perform registration and/or initialization when parts related to the automatic transaxle are replaced.

Click here

Tech Tips

After performing repair, clear the DTCs and perform the following procedure to check that DTCs are not output.


  1. Perform the D Position Shift Test inspection in Road Test.

    Click here

  2. Check for DTCs again.

    Click here


  1. DATA LIST

    Note

    In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not.

    Tech Tips

    Using the GTS to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals may be discovered before parts or wiring is disturbed. Reading the Data List information early in troubleshooting is one way to save diagnostic time.


    1. Warm up the engine.

    2. Turn the ignition switch off.

    3. Connect the GTS to the DLC3.

    4. Turn the ignition switch to ON.

    5. Turn the GTS on.

    6. Enter the following menus: Powertrain / Transmission / Data List / NC Sensor Speed.

    7. Read the Data List according to the display on the GTS.


      Powertrain > Transmission > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      NC Sensor Speed Counter gear speed

      Min.: 0 rpm

      Max.: 12750 rpm

      		 - -

      Powertrain > Transmission > Data List
      Tester Display
      NC Sensor Speed

      Tech Tips


      • NC Sensor Speed is always 0 while driving: Open or short in the sensor or circuit.

      • NC Sensor Speed is always more than 0 and less than 300 rpm while driving the vehicle at 16 km/h (10 mph) or more: Sensor malfunction, improper installation, or intermittent connection malfunction in the circuit.

PROCEDURE


  1. READ VALUE USING GTS (NC SENSOR SPEED AND NC SENSOR VOLTAGE)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Transmission / Data List / NC Sensor Speed and NC Sensor Voltage.

    5. Read the Data List according to the display on the GTS.


      Powertrain > Transmission > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      NC Sensor Speed Counter gear speed

      Min.: 0 rpm

      Max.: 12750 rpm

      		 - -
      NC Sensor Voltage NC sensor voltage

      Min.: 0.000 V

      Max.: 4.999 V

      		 0.1 to 1.9 V: Engine idling -

      Powertrain > Transmission > Data List
      Tester Display
      NC Sensor Speed
      NC Sensor Voltage
      Result
      Result Proceed to
      Data List values are normal A
      Data List values are not normal B

    A

    GO TO STEP 5 Click here

    B

  2. INSPECT TRANSMISSION REVOLUTION SENSOR (NC) (NC TERMINAL)


    1. B00403FC17
      *a

      Front view of wire harness connector

      (to Transmission Wire)

      Disconnect the C85 transmission wire connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      C85-21 (NCO) - Body ground Always 99 to 101 Ω

    3. Turn the ignition switch to ON.

    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      C85-22 (NCB) - Body ground Ignition switch ON 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM) Click here

    OK

  3. INSPECT TRANSMISSION WIRE (TRANSMISSION REVOLUTION SENSOR (NC))


    1. B003ZNGC04
      *1 Transmission Wire
      *a Transmission Revolution Sensor (NC) Side
      *b Wire Harness Connector Side

      Disconnect the transmission revolution sensor (NC) connector.

      When Not Using the Engine Support Bridge: Click here

      When Using the Engine Support Bridge: Click here

    2. Disconnect the C85 transmission wire connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 (transmission revolution sensor (NC) side) - 22 (NCB) (wire harness connector side) Always Below 1 Ω
      2 (transmission revolution sensor (NC) side) - 21 (NCO) (wire harness connector side) Always Below 1 Ω
      1 (transmission revolution sensor (NC) side) or 22 (NCB) (wire harness connector side) - Body ground Always 10 kΩ or higher
      2 (transmission revolution sensor (NC) side) or 21 (NCO) (wire harness connector side) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE TRANSMISSION REVOLUTION SENSOR (NC) Click here

    NG

    REPAIR OR REPLACE TRANSMISSION WIRE When Not Using the Engine Support Bridge: Click here
    REPAIR OR REPLACE TRANSMISSION WIRE When Using the Engine Support Bridge: Click here

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


    1. Disconnect the C85 transmission wire connector.

    2. Disconnect the C1 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      C85-22 (NCB) - C1-73 (NCB) Always Below 1 Ω
      C85-21 (NCO) - C1-72 (NCO) Always Below 1 Ω
      C85-22 (NCB) or C1-73 (NCB) - Body ground Always 10 kΩ or higher
      C85-21 (NCO) or C1-72 (NCO) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

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

    OK

  5. REPLACE ECM


    1. Replace the ECM.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

    PERFORM REGISTRATION Click here