MULTI-MODE MANUAL TRANSAXLE SYSTEM, Diagnostic DTC:P0725

DTC Code DTC Name
P0725 Engine Speed Input Circuit

DESCRIPTION

The ECM detects the engine speed signals (NE) using the crankshaft position (CKP) sensor. The TCM controls the transaxle in accordance with two engine speed signals. One signal is received directly from the ECM through a serial communication line. The other signal is received from the ECM via the Controller Area Network (CAN) communication. If the TCM detects no engine speed signals despite the engine speed signal via CAN being received while the vehicle is running, the ECU interprets this as a malfunction in the engine speed signal circuit. The ECU sets the DTC and illuminates the multi-mode manual transaxle warning light.

DTC No. DTC Detection Condition Trouble Area
P0725

The TCM detects the following conditions simultaneously for 1 second:

(1-trip detection logic)


  1. Engine speed is 400 rpm or less (serial communication circuit).

  2. Engine speed is 400 rpm or more (CAN communication circuit).

  3. Engine speed difference between signal from serial communication circuit and signal from CAN communication circuit is 400 rpm or more.

  • Wire harness or connector

  • TCM

  • ECM

WIRING DIAGRAM

A01VI0CE01

PROCEDURE


  1. CHECK ANY OTHER DTCS OUTPUT (ENGINE SPEED SIGNAL CIRCUIT)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

    4. Enter the following menus: Powertrain / Engine and ECT.

    5. Read DTCs.

      Result
      Result Proceed to
      DTC P0335 is not output A
      DTC P0335 is output B

      Check the DTC output related to the engine speed signal circuit in the engine control system. If DTC P0335 is set together with DTC P0725, troubleshoot DTC P0335 first.


    B

    GO TO DTC P0335 Click here

    A

  2. INSPECT TCM


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

    4. Enter the following menus: Powertrain / Multi-Mode M/T / Data List / Backup Engine Speed.

    5. In accordance with the display on the tester, read the Data List.

      Multi-Mode M/T
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note

      Backup Engine Speed

      [Bacup Engin Spd]

      Back-up engine speed:

      Min.: 0 rpm, Max.: 8160 rpm

      720 to 820 rpm: Idling

      0 rpm: Engine stopped

      		 0 rpm displayed when malfunction in CAN communication
    6. A01VGSEE01
      Text In Illustration
      *a

      Component with harness connected

      (TCM)

      Connect the oscilloscope probes to the NE terminal and the body ground.

    7. Check the signal waveform.

      Terminals NE - Body ground
      Tool Setting 5 V/DIV., 5 ms./DIV.
      Vehicle Condition Engine idling
      OK
      When the Backup Engine Speed indicates an idling speed on the intelligent tester, a waveform similar to that in the illustration is output.

    NG

    CHECK HARNESS AND CONNECTOR (TCM - ECM) Click here

    OK

  3. REPLACE TCM


    1. Replace the TCM Click here.


    NEXT

  4. PERFORM INITIALIZATION


    1. Perform the initialization and learning for multi-mode manual transaxle system Click here.


    NEXT

    END

  5. CHECK HARNESS AND CONNECTOR (TCM - ECM)


    1. Disconnect the TCM connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A47-10 (NE) - A59-79 (NEO) Always Below 1 Ω
      A47-10 (NE) - Body ground Always 10 kΩ or higher

    OK

    REPLACE ECM (See page ENGINE CONTROL (1ND-TV) > ECM > REMOVAL)

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR