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

C279530E01

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

    w/o Glow Plug Controller:Click here

    w/ Glow Plug Controller: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. C276272C02

      *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 hereClick here

    Result

    Proceed to

    NEXT
    NEXT

  4. PERFORM INITIALIZATION

    1. Perform the initialization and learning procedure.

      Click here

    Result

    Proceed to

    NEXT
    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

      A108-10 (NE) - A101-79 (NEO)

      Always

      Below 1 Ω

      A108-10 (NE) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE ECM

    w/o Glow Plug Controller:Click here

    w/ Glow Plug Controller:Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR