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 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 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.

A01W1C0E02
Text in Illustration
*1 Counter Gear *2 Clutch Drum
*3 Output Speed Sensor NC *4 Input Speed Sensor NT
DTC No. DTC Detection Condition Trouble Area
P079112

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


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

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

  3. 2 seconds

  4. 1-trip detection logic

  • Wiring harness connector

  • Transmission revolution sensor (Output speed sensor NC)

  • Transmission wire

  • ECM
P079114

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


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

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

  3. 2 seconds

  4. 1-trip detection logic

  • Wiring harness connector

  • Transmission revolution sensor (Output speed sensor NC)

  • Transmission wire

  • ECM
P079131

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


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

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

  3. 2 seconds

  4. 1-trip detection logic

  • Wiring harness connector

  • Transmission revolution sensor (Output speed sensor NC)

  • Transmission wire

  • ECM

MONITOR DESCRIPTION

The NT terminal of the ECM detects a revolution signal from the input speed sensor NT (input RPM). The ECM calculates gear shifts by 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 is less than 300 rpm*1 although the output shaft revolution is more than 1000 rpm*2, the ECM 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

A01W3NZE08

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 / Transmission / Data List.

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

      Transmission
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      NC Sensor Speed

      Counter Gear Speed/

      Min.: 0 rpm

      Max.: 12750 rpm

      		 - Data is displayed in increments of 50 rpm

      Tech Tips


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

      • NC Speed Sensor 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.

    2. A01W2OJ

      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 sensor and transmission valve body assembly.

    NG

    REPAIR OR REPLACE TRANSMISSION REVOLUTION SENSOR Click here

    OK

  2. INSPECT TRANSMISSION WIRE


    1. A01W53CE06
      Text in Illustration
      *a

      Component without harness connected

      (Transmission Wire)
      *b Wiring harness connector side
      *c Transmission revolution sensor side

      Disconnect the transmission revolution 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

    NG

    REPLACE TRANSMISSION WIRE Click here

    OK

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


    1. Disconnect the D87 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D87-73 (NCB) - D7-4 (NCB) Always Below 1 Ω
      D87-74 (NCO) - D7-3 (NCO) Always Below 1 Ω
      D87-73 (NCB) or D7-4 (NCB)- Body ground and other terminals Always 10 kΩ or higher
      D87-74 (NCO) or D7-3 (NCO) - Body ground and other terminals Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. INSPECT WIRING HARNESS CONNECTOR


    1. Remove the wiring harness connector.

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

      A01W2OOE02
      Text in Illustration
      *1 Wiring Harness Connector - -
      *a Transmission wire side *b ECM side
      Standard Resistance
      Tester Connection Condition Specified Condition
      D7-3 (NCO) - A-3 (NCO) Always Below 1 Ω
      D7-4 (NCB) - A-4 (NCB) Always Below 1 Ω
      D7-3 (NCO) - All other terminals Always 10 kΩ or higher
      D7-4 (NCB) - All other terminals Always 10 kΩ or higher

    NG

    REPLACE WIRING HARNESS CONNECTOR Click here

    OK

  5. REPLACE TRANSMISSION REVOLUTION SENSOR


    1. Replace the transmission revolution sensor Click here.


    NEXT

  6. CHECK IF DTC OUTPUT RECURS (DTC P079112, P079114 AND/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.

    4. Perform the monitor drive pattern Click here.

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

    6. Read the DTCs using the GTS.

      Result
      Result Proceed to
      DTC P079112, P079114 and/or P079131 is output A
      DTCs are not output B

    A

    REPLACE ECM Click here

    B

    END