ECD SYSTEM(w/o Glow Plug Controller), Diagnostic DTC:P0812

DTC Code DTC Name
P0812 Reverse Input Circuit

DESCRIPTION

This diagnostic trouble code for the gear shift indicator system is set when the ECM detects a problem with the back-up light switch circuit. The back-up light switch is installed to the transaxle and it receives power from the battery via the wire harness. When reverse is selected, the back-up light switch will turn on and power will be sent to terminal R of the ECM. If the vehicle is operated in third gear or higher for 5 seconds or longer while the back-up light switch remains on, the ECM will judge the situation as abnormal and set this diagnostic trouble code. Refer to the combination meter section for more information about the gear shift indicator system.

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DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P0812

Reverse Input Circuit

When both of the following conditions are met (3 trip detection logic):

(a) While the back-up light remains on, the vehicle is operated in third gear for 5 seconds or longer.

(b) The engine speed sensor, vehicle speed sensor and clutch switch are normal.

  • Short in back-up light switch assembly circuit

  • Back-up light switch assembly

  • ECM

-

DTC stored
Table 1. DTC Detection Drive Pattern

DTC No.

DTC Detection Drive Pattern

P0812

Vehicle driving in 3rd gear for 5 seconds or more
Table 2. Related Data List

DTC No.

Data List

P0812

Reverse Switch

WIRING DIAGRAM

A358354E01

CAUTION / NOTICE / HINT

Note:

When replacing the ECM, perform ECM Initialization and Registration.

Click here

Tip:

  • When the ECM must be replaced, before replacing the ECM, perform the "Learning Values Save" function using the GTS. Then after installing a new ECM, perform all of the initialization and registration procedures for the "Learning Values Write" function by following the instructions shown on the GTS display.

  • Read freeze frame data using the GTS. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, and other data from the time the malfunction occurred.

PROCEDURE

  1. READ VALUE USING GTS (REVERSE SWITCH)

    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 / Data List / All Data / Reverse Switch.

      Powertrain > Engine and ECT > Data List

      Tester Display

      Reverse Switch

    5. Check the value displayed on the GTS when the shift lever in neutral.

    Result

    Condition

    Reverse Switch

    Proceed to

    Shift lever in neutral

    OFF

    A

    ON

    B
    A

    CHECK FOR INTERMITTENT PROBLEMS

    Click here

    B

  2. INSPECT BACK-UP LIGHT SWITCH ASSEMBLY

    1. Inspect the back-up light switch assembly.

      Click here

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE BACK-UP LIGHT SWITCH ASSEMBLYClick here

    OK

  3. REPAIR OR REPLACE HARNESS OR CONNECTOR (BACK-UP LIGHT CIRCUIT)

    1. Repair or replace the harness or connector (ECM - back-up light switch assembly - rear light assembly).

    Result

    Proceed to

    NEXT
    NEXT

  4. CHECK WHETHER DTC OUTPUT RECURS (DTC P0812)

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear the DTCs.

      Powertrain > Engine and ECT > Clear DTCs

    5. Turn the ignition switch off and wait for 30 seconds or more.

    6. Drive the vehicle in 3rd gear for 5 seconds or more.

    7. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.

    8. Read the pending DTCs.

      Powertrain > Engine and ECT > Trouble Codes

      Result

      Result

      Proceed to

      DTC is not output

      A

      DTC P0812 is output

      B
    A

    END

    B

    REPLACE ECMClick here

  5. REPLACE BACK-UP LIGHT SWITCH ASSEMBLY

    1. Replace the back-up light switch assembly.

      Click hereClick here

    Result

    Proceed to

    NEXT
    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIREDClick here

  6. REPLACE ECM

    1. Replace the ECM.

      Click here

    Result

    Proceed to

    NEXT
    NEXT

  7. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear the DTCs.

      Powertrain > Engine and ECT > Clear DTCs

    5. Turn the ignition switch off and wait for 30 seconds or more.

    6. Drive the vehicle in 3rd gear for 5 seconds or more.

    7. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.

    8. Confirm that the pending DTC is not output again.

      Powertrain > Engine and ECT > Trouble Codes

    Result

    Proceed to

    NEXT
    NEXT

    END