MULTI-MODE MANUAL TRANSAXLE SYSTEM, Diagnostic DTC:P0885, P0887

DTC Code DTC Name
P0885 TCM Power Relay Control Circuit / Open
P0887 TCM Power Relay Control Circuit (Short)

DESCRIPTION

The multi-mode manual transaxle system has a dedicated power supply circuit. While the ignition switch is turned to ON, the transmission control ECU outputs the power from the MREL terminal to operate the MMT relay. Then, the power is supplied to the +BM terminal of the transmission control ECU through the MMT relay. The voltage (+BM) is monitored and when it is low (4.00 V or less) despite the voltage being supplied to the MREL circuit, the transmission control ECU determines that there is a malfunction in the multi-mode manual transaxle system and sets a DTC. When the voltage (+BM) is high (4.00 V or more) although the voltage is not supplied to the MREL circuit, the transmission control ECU sets a DTC.

DTC No. DTC Detecting Condition Trouble Area
P0885

The transmission control ECU detects the following conditions simultaneously:

(1-trip detection logic)


  1. Voltage is supplied to MREL circuit.

  2. +BM voltage is less than 4.00 V for 0.5 seconds.

  • AMT fuse

  • MMT relay

  • Wire harness or connector

  • Transmission control ECU
P0887

The transmission control ECU detects the following conditions simultaneously:

(1-trip detection logic)


  1. No voltage is supplied to MREL circuit.

  2. +BM voltage is more than 4.00 V for 0.1 seconds.

  • MMT relay

  • Wire harness or connector

  • Transmission control ECU

WIRING DIAGRAM

A01389XE01

INSPECTION PROCEDURE

Note

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE


  1. INSPECT MMT RELAY


    1. A0138UKE01

      Remove the MMT relay from the engine room relay block No. 2.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 - 5 Battery voltage is not applied 10 kΩ or higher
      Battery voltage applied to terminals 1 and 2 Below 1 Ω

    3. Reinstall the MMT relay.


    NG

    REPLACE MMT RELAY

    OK

  2. INSPECT TRANSMISSION CONTROL ECU (+BM TERMINAL INPUT VOLTAGE)


    1. A0137TQE08
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Transmission Control ECU)

      Disconnect the transmission control ECU connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A49-2 (+BM) - A49-1 (PGND) Ignition switch off Below 1 V
      A49-2 (+BM) - A49-1 (PGND) Ignition switch ON 11 to 14 V
      Result
      Result Proceed to
      NG A
      OK B

    B

    REPLACE TRANSMISSION CONTROL ECU Click here

    A

  3. CHECK HARNESS AND CONNECTOR (TRANSMISSION CONTROL ECU - BODY GROUND)


    1. A0137TQE09
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Transmission Control ECU)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A49-1 (PGND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. INSPECT TRANSMISSION CONTROL ECU (MREL TERMINAL OUTPUT VOLTAGE)


    1. Reconnect the transmission control ECU connectors.

    2. Turn the ignition switch to ON.

    3. A0137QSE09
      Text In Illustration
      *a

      Component with harness connected

      (Transmission Control ECU)

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A28-5 (MREL) - Body ground Ignition switch off Below 1 V
      Ignition switch ON 11 to 14 V

    NG

    REPLACE TRANSMISSION CONTROL ECU Click here

    OK

  5. CHECK HARNESS AND CONNECTOR (TRANSMISSION CONTROL ECU - MMT RELAY)


    1. Disconnect the A28 transmission control ECU connectors.

    2. Remove the MMT relay from the engine room relay block No. 2.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A28-5 (MREL) - MMT relay (1) Always Below 1 Ω
      A49-2 (+BM) - MMT relay (5) Always Below 1 Ω
      A28-5 (MREL) or MMT relay (1) - Body ground Always 10 kΩ or higher
      A49-2 (+BM) or MMT relay (5) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK HARNESS AND CONNECTOR (BATTERY - MMT RELAY)


    1. A0138C3E02
      Text in Illustration
      *1 Engine room relay block No. 2
      *2 MMT relay Holder

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      MMT relay (terminal 3) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. CHECK HARNESS AND CONNECTOR (MMT RELAY - BODY GROUND)


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

      Standard Resistance
      Tester Connection Condition Specified Condition
      MMT relay (terminal 2) -Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. REPLACE TRANSMISSION CONTROL ECU


    1. Replace the transmission control ECU Click here.


    NEXT

  9. PERFORM INITIALIZATION


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


    NEXT

    END