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 being driven, the ECU interprets this as a malfunction in the engine speed signal circuit. The ECU stores this DTC and illuminates the multi-mode manual transaxle warning light.

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Warning Indicate Memory
P0725 Engine Speed Input Circuit

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.

  • Open or short in NE signal circuit

  • TCM

  • ECM

 Does not come on Comes on DTC stored

WIRING DIAGRAM

B00449AE03

PROCEDURE


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


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

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


      Powertrain > Engine and ECT > Trouble Codes

    5. Read the DTCs.

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

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


    B

    GO TO DTC P0335 Click here

    A

  2. INSPECT TCM


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

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

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


      Powertrain > Multi-Mode M/T > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Backup Engine Speed 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

      Powertrain > Multi-Mode M/T > Data List
      Tester Display
      Backup Engine Speed
    6. B0042T6C02
      *a

      Component with harness connected

      (TCM)

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

    7. Check the signal waveform.

      Item Condition
      Terminals NE - Body ground
      Tool setting 5 V/DIV., 5 ms./DIV.
      Vehicle condition Engine idling
      OK
      When Backup Engine Speed indicates an idle speed, a waveform similar to that in the illustration is output.
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (TCM - ECM) Click here

    OK

  3. REPLACE TCM


    1. Replace the TCM.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

    PERFORM INITIALIZATION Click here

  4. 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
      A108-10 (NE) - A169-6 (NEO) Always Below 1 Ω
      A108-10 (NE) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR