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

The output speed sensor NC detects the rotation speed of the counter gear, which indicates the intermediate shaft revolution (speed) of the transaxle. By comparing the input speed sensor NT signal with the output speed sensor NC signal, the TCM 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.

A01IJ8KC02
*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

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


    DTC Detection Condition 1:

  1. The battery voltage is 8 V or more, the engine switch is on (IG) and the starter is off.

  2. The output speed sensor NC input voltage is more than 1.9 V.

  3. 2 seconds

  4. 1-trip detection logic


    DTC Detection Condition 2:

  1. The battery voltage is 8 V or more, the engine switch is on (IG) and the starter is off.

  2. The output speed sensor NC input voltage is less than 0.1 V.

  3. 2 seconds

  4. 1-trip detection logic

  • Output speed sensor NC (Transmission revolution sensor)

  • Transmission wire

  • TCM

 Comes on DTC stored
P0793 Intermediate Shaft Speed Sensor "A"

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


  1. The vehicle is being driven with the shift lever in D at a vehicle speed of 25 km/h (16 mph) or more.

  2. The speed indicated by the output speed sensor NC signal is less than 300 rpm.

  3. 2 seconds

  4. 1-trip detection logic

  • Output speed sensor NC (Transmission revolution sensor)

  • Transmission wire

  • TCM

 Comes on DTC stored

MONITOR DESCRIPTION

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

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 TCM interprets this as a malfunction, 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

A01IFRNE04
*a Transmission Wire
*b Transmission Revolution Sensor (Output Speed Sensor NC)
*c Automatic Transaxle Assembly

CAUTION / NOTICE / HINT

Note

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

Click here

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.

  • 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 and drive the vehicle for 2 seconds or more at 25 km/h (16 mph) or more.

      Click here

    2. Check for DTCs again.

      Click here


  1. DATA LIST


    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 / ECT / Data List.

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


      Powertrain > ECT > 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 > ECT > 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 malfunction, improper installation, or intermittent connection malfunction in the circuit.

PROCEDURE


  1. INSPECT TRANSMISSION REVOLUTION SENSOR (SPEED SENSOR INSTALLATION)


    1. Remove the transmission valve body assembly.

      Click here

    2. A01IHNU

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

      Click here

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

    NG

    REPAIR OR REPLACE TRANSMISSION REVOLUTION SENSOR Click here

    OK

  2. INSPECT TRANSMISSION WIRE


    1. A01IKTZC02
      *a

      Component without harness connected

      (Transmission Wire)
      *b Transmission Revolution Sensor Side
      *c TCM Side

      Remove the TCM.

      Click here

    2. Disconnect the transmission revolution sensor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 (NCO) sensor side - 3 (NCO) TCM side Always Below 1 Ω
      4 (NCB) sensor side - 4 (NCB) TCM 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. REPLACE TRANSMISSION REVOLUTION SENSOR

    Click here

    Result
    Proceed to
    NEXT

    NEXT

  4. CHECK IF DTC OUTPUT RECURS (DTC P0791 AND/OR P0793)


    1. Connect the GTS to the DLC3.

    2. Start the engine and turn the GTS on.

    3. Clear the DTCs.

      Click here


      Powertrain > ECT > Clear DTCs

      Tech Tips

      Write down the currently output DTCs before clearing them.

    4. Perform the monitor drive pattern.

      Click here

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


      Powertrain > ECT > 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 TCM Click here

    B

    END