AUTOMATIC TRANSAXLE SYSTEM, Diagnostic DTC:P0791, P0793

DTC Code DTC Name
P0791 Intermediate Shaft Speed Sensor "A" Circuit
P0793 Intermediate Shaft Speed Sensor "A"

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, thus, providing smooth gear shifts.

A002ALZC01
*1 Counter Gear *2 Clutch Drum
*3 Output Speed Sensor NC *4 Input Speed Sensor NT
DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory
P0791 Intermediate Shaft Speed Sensor "A" Circuit When the speed sensor input voltage is either more than 1.9 V or less than 0.1 V for 2 seconds or more. (1-trip detection logic)

  • Transmission revolution sensor (speed sensor NC)

  • Transmission wire

  • Wiring harness connector

  • ECM

 Comes on DTC stored
P0793 Intermediate Shaft Speed Sensor "A" When the vehicle speed is 25 km/h (15.5 mph) or higher, the counter gear speed is less than 300 rpm for 2 seconds or more. (1-trip detection logic)

  • Transmission revolution sensor (speed sensor NC)

  • Transmission wire

  • Wiring harness connector

  • ECM

 Comes on DTC stored

MONITOR DESCRIPTION

The NT terminal of the ECM detects a revolution signal from the speed sensor (NT) (input RPM). The ECM calculates gear shifts by 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 is less than 300 rpm*1 although the output shaft revolution 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

A002AJQE07

CAUTION / NOTICE / HINT

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. 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.


    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 / Engine and ECT / Data List.

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


      Powertrain > Engine > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      SPD (NC) Counter Gear Speed

      Min.: 0 rpm

      Max.: 12750 rpm

      		 - Data is displayed in increments of 50 rpm

      Powertrain > Engine > Data List
      Tester Display
      SPD (NC)

      Tech Tips


      • SPD (NC) is always 0 while driving: Open or short in the sensor or circuit.

      • SPD (NC) 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 (SPEED SENSOR INSTALLATION)


    1. Remove the valve body assembly.

    2. A0028K1

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

      Click here

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

    NG

    REPAIR OR REPLACE TRANSMISSION REVOLUTION SENSOR Click here

    OK

  2. INSPECT TRANSMISSION WIRE


    1. A0027ROC02
      *a

      Component without harness connected

      (Transmission Wire)
      *b Wiring harness connector side
      *c Sensor side

      Disconnect the speed sensor connector from the transmission wire.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 (NCO) sensor side - A-3 (NCO) wiring harness connector side Always Below 1 Ω
      4 (NCB) sensor side - A-4 (NCB) wiring harness connector side Always Below 1 Ω
      3 (NCO) sensor side - Body ground and other terminals Always 10 kΩ or higher
      4 (NCB) sensor 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 (ECM - WIRING HARNESS CONNECTOR)


    1. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      C1-118 (NCB) - C2-4 (NCB) Always Below 1 Ω
      C1-117 (NCO) - C2-3 (NCO) Always Below 1 Ω
      C1-118 (NCB) or C2-4 (NCB)- Body ground and other terminals Always 10 kΩ or higher
      C1-117 (NCO) or C2-3 (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.

      A002A36C06
      *a

      Component without harness connected

      (Wiring Harness Connector)

      		 *b ECM side
      *c Transmission wire side - -

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      C2-3 (NCO) - A-3 (NCO) Always Below 1 Ω
      C2-4 (NCB) - A-4 (NCB) Always Below 1 Ω
      C2-3 (NCO) - All other terminals Always 10 kΩ or higher
      C2-4 (NCB) - All other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE WIRING HARNESS CONNECTOR Click here

    OK

  5. REPLACE TRANSMISSION REVOLUTION SENSOR

    Click here

    Result
    Proceed to
    NEXT

    NEXT

  6. CHECK IF DTC OUTPUT RECURS (SEE IF DTC P0791 AND/OR P0793 IS OUTPUT AGAIN)


    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 > Engine > Clear DTCs

    4. Perform the monitor drive pattern.

      Click here

    5. Enter the following menus: / Engine and ECT / Trouble Codes.


      Powertrain > Engine > Trouble Codes

    6. Read the DTCs using the GTS.

      Result
      Result Proceed to
      Only DTC P0791 or P0793 is output A
      DTCs are not output B

    A

    REPLACE ECM Click here

    B

    END