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

This sensor detects the rotation speed of the counter gear, which indicates the intermediate shaft revolution (speed) of the transaxle. By comparing the input turbine speed signal (NT) with the counter gear speed sensor signal (NC), the ECM detects the shift timing of the gears and appropriately controls the engine torque and hydraulic pressure according to various conditions. As a result, the gears shift smoothly.

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory Note
P079112 Intermediate Shaft Speed Sensor "A" Circuit Short to Battery When the speed sensor input voltage is higher than 1.9 V for 2 sec. or more. (1-trip detection logic)

  • Harness and connector

  • Wiring harness connector

  • Transmission wire

  • Speed sensor NC (transmission revolution sensor)

  • ECM

 Comes on DTC stored SAE: P07C6
P079114 Intermediate Shaft Speed Sensor "A" Circuit Short to Ground or Open When the speed sensor input voltage is below 0.1 V for 2 sec. or more. (1-trip detection logic)

  • Harness and connector

  • Wiring harness connector

  • Transmission wire

  • Speed sensor NC (transmission revolution sensor)

  • ECM

 Comes on DTC stored SAE: P07C5
P079131 Intermediate Shaft Speed Sensor "A" No Signal When the vehicle speed is 25 km/h (15.5 mph) or more, the counter gear speed is less than 300 rpm for 2 sec. or more. (1-trip detection logic)

  • Harness and connector

  • Wiring harness connector

  • Transmission wire

  • Speed sensor NC (transmission revolution sensor)

  • ECM

 Comes on DTC stored SAE: P0793

MONITOR DESCRIPTION

The NT terminal of the ECM detects a revolution signal from the speed sensor (NT) (input RPM). The ECM calculates gear shifts comparing the speed sensor (NT) with the speed sensor (NC).

While the vehicle is being driven in 2nd, 3rd, 4th or 5th gear with the shift lever in D, if the input shaft revolution (speed) is less than 300 rpm*1 and the output shaft revolution (speed) is more than 1000 rpm*2, the ECM interprets this as a fault, illuminates the MIL and stores a DTC.

*1: Pulse is not output or is irregularly output.

*2: The vehicle speed is 50 km/h (31 mph) or more.

WIRING DIAGRAM

Refer to DTC P071512.

Click here

CAUTION / NOTICE / HINT

Note

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

Click here


  1. DATA LIST

    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.

    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.


    1. Warm up the engine.

    2. Turn the engine switch off.

    3. Connect the GTS to the DLC3.

    4. Turn the engine switch on (IG).

    5. Turn the GTS on.

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

    7. According to the display on the GTS, read the Data List.


      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

      		 0 rpm: Vehicle stopped The data is displayed in increments of 50 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 50 km/h (31 mph) or more: Sensor trouble, improper installation, or intermittent connection trouble of the circuit.

PROCEDURE


  1. INSPECT TRANSMISSION REVOLUTION SENSOR INSTALLATION


    1. Remove the transmission valve body assembly.

      Click here

    2. A01HHF4

      Make sure that the connector is properly connected, and check the transmission revolution sensor installation.

      OK
      The installation bolts are tightened properly and there is no clearance between the sensor and transaxle case.
      Result
      Proceed to
      OK
      NG

    NG

    SECURELY INSTALL OR REPLACE TRANSMISSION REVOLUTION SENSOR Click here

    OK

  2. INSPECT TRANSMISSION WIRE


    1. A01HEQVC05
      *1 Transmission Wire
      *a Transmission Revolution Sensor Side
      *b Wiring Harness Connector Side

      Disconnect the transmission revolution sensor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      NCB transmission revolution sensor side - A-4 (NCB) wiring harness connector side Always Below 1 Ω
      NCO transmission revolution sensor side - A-3 (NCO) wiring harness connector side Always Below 1 Ω
      NCB transmission revolution sensor side or A-4 (NCB) wiring harness connector side - Body ground and other terminals Always 10 kΩ or higher
      NCO transmission revolution sensor side or A-3 (NCO) wiring harness connector side - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE TRANSMISSION WIRE Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (WIRING HARNESS CONNECTOR - ECM)


    1. Disconnect the C21 wiring harness connector.

    2. Disconnect the C20 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      C21-4 (NCB) - C20-73 (NCB) Always Below 1 Ω
      C21-3 (NCO) - C20-74 (NCO) Always Below 1 Ω
      C21-4 (NCB) or C20-73 (NCB) - Body ground and other terminals Always 10 kΩ or higher
      C21-3 (NCO) or C20-74 (NCO) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. INSPECT WIRING HARNESS CONNECTOR


    1. Remove the wiring harness connector.

      A01HJB6C11
      *1 Wiring Harness Connector - -
      *a Transmission Wire Side *b ECM Side

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A-4 (NCB) - C21-4 (NCB) Always Below 1 Ω
      A-3 (NCO) - C21-3 (NCO) Always Below 1 Ω
      A-4 (NCB) - All other terminals except C21-4 (NCB) Always 10 kΩ or higher
      A-3 (NCO) - All other terminals except C21-3 (NCO) Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE WIRING HARNESS CONNECTOR Click here

    OK

  5. REPLACE TRANSMISSION REVOLUTION SENSOR


    1. Replace the transmission revolution sensor.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  6. CHECK IF DTC OUTPUT RECURS (DTC P079112, P079114 OR P079131)


    1. Connect the GTS to the DLC3.

    2. Start the engine and turn the GTS on.

    3. Clear the DTCs.

      Click here

      Tech Tips

      Write down the currently output DTCs before clearing them.


      Powertrain > Transmission > Clear DTCs

    4. Perform the monitor drive pattern.

      Click here

    5. Enter the following menus: Powertrain / Transmission / Trouble Codes.


      Powertrain > Transmission > Trouble Codes

    6. Read the DTCs using the GTS.

      Result
      Result Proceed to
      Only P079112, P079114 or P079131 is output A
      DTCs are not output B

    A

    REPLACE ECM Click here

    B

    END