EMISSION CONTROL SYSTEM, Diagnostic DTC:43

DTC Code DTC Name
43 Starter Signal Circuit Malfunction

DESCRIPTION

When the engine is being cranked, the intake air flow is slow, so fuel vaporization is poor. A rich mixture is therefore necessary in order to achieve good startability. While the engine is being cranked, the battery positive voltage is applied to terminal STA of the emission ECU. The starter signal is mainly used to increase the fuel injection volume for the starting injection control and after-start injection control.

DTC No. DTC Detecting Condition Trouble Area
43 No starter signal to emission ECU

  • Open or short in starter signal circuit


  • Emission ECU

WIRING DIAGRAM

A01KI8CE01

INSPECTION PROCEDURE

Tech Tips

This DTC chart is based on the premise that the engine is being cranked under normal conditions. If the engine does not crank, proceed to the problem symptoms table on page Click here.

PROCEDURE


  1. CHECK EMISSION CONTROL ECU


    1. Start the engine.

    2. A01KHLFE10

      Measure the voltage between terminals STA and E1 of the emission ECU connector during cranking.

      VOLTAGE
      6.0 V or more

    OK

    CHECK FOR PROBLEM SYMPTOMS TABLE Click here

    NG

  2. CHECK FUSE (ST NO.2)


    1. A01KHANE02
      Text in Illustration
      *1 ST NO.2

      Remove the ST NO.2 fuse from the R/B No.2.

    2. Check continuity of ST No.2 fuse.

      OK
      CONTINUITY

    NG

    REPLACE FUSE (ST NO.2)

    OK

  3. CHECK WIRE HARNESS AND CONNECTOR (EMISSION ECU-ST RELAY)


    1. Disconnect the battery negative (-) terminal.

    2. Remove the starter relay (Marking: ST).

    3. A01KH0WE04
      A01KFE5E02

      Disconnect the emission ECU connector.

      Text in Illustration
      *1 ST Relay

    4. Check the continuity between terminals 3 of the starter relay in the R/B No.2 and STA of the ECU connector Click here.

      Note

      Do not insert the tester hard in procedure (C), or the holder may be damaged.

      RESISTANCE
      1 Ω or less

    NG

    REPAIR OR REPLACE WIRE HARNESS OR CONNECTOR

    OK

    CHECK AND REPLACE EMISSION CONTROL ECU Click here