Code No. P081D: Neutral Position Switch Circuit


OPERATION



  • The power voltage is supplied to the neutral position switch (terminal No. 2) from the ETACS-ECU (C-417 ETACS-ECU connector terminal No. 5).
  • The ON/OFF signal is inputted to the AS&G-ECU (terminal No. 28) from the neutral position switch (terminal No. 1).

FUNCTION



  • The AS&G-ECU detects the gearshift lever position by using the signals of the neutral position switch.
  • In response to the signal, the AS&G-ECU controls the AS&G system.

TROUBLE JUDGMENT


Check Conditions
  • Ignition switch is "ON" position.
  • The diagnosis code P0833 is not detected.
  • Ambient temperature is more than -5°C
  • The diagnosis code U0141 is not detected.
Judgement Criterion
  • When you drive the vehicle at more than 60 km/h at least one time, the ON/OFF signal of the neutral position switch does not change even once although the ON/OFF signal of the clutch interlock switch is detected more than 10 times.

FAIL-SAFE AND BACKUP FUNCTION



  • In the normal operation, the auto stop is prohibited.

PROBABLE CAUSES



  • Open/short circuit or harness damage in neutral position switch circuit or loose connector contact
  • Failed neutral position switch
  • Failed installation of neutral position switch
  • Failed system inside transmission
  • Failed AS&G-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III data list

  • Refer to Data List Reference Table .

  1. item 8: Neutral position switch

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Go to Step 2.

STEP 2. Connector check: B-110 neutral position switch connector

Q. Is the check result normal?
Go to Step 3.
Repair or replace the connector.

STEP 3. Continuity check on B-110 neutral position switch connector.

  • Disconnect connector, and check at switch side.
  • Continuity check between terminal No. 1 and terminal No. 2.
OK:
    Continuity (Gearshift lever position: Neutral)
    No continuity (Gearshift lever position: Except neutral)

Q. Is the check result normal?
Go to Step 6.
Go to Step 4.

STEP 4. Check the installation state of the neutral position switch.

Q. Is the check result normal?
Go to Step 5.
Repair.

STEP 5. Check the neutral position switch itself.

  • Check the neutral position switch itself (Refer to GROUP 22A - On-vehicle service - Neutral Position Switch Check ).

Q. Is the check result normal?
The area affecting the neutral position switch inside the transmission can possibly be abnormal. Overhaul and repair the transmission, or change the transmission.
Replace the neutral position switch.

STEP 6. Perform voltage measurement at B-110 neutral position switch connector.

  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal No. 2 and earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 8.
Go to Step 7

STEP 7. Connector check: C-417 ETACS-ECU connector

Q. Is the check result normal?

    Check intermediate connectors C-04, C-127, B-108 <4N1>, A-16 <4A9> and repair if necessary. If intermediate connectors are normal, check and repair harness between C-417 (terminal No. 5) ETACS-ECU connector and B-110 (terminal No. 2) neutral position switch connector.

    • Check power supply line for open/short circuit.
Repair or replace the connector.

STEP 8. Connector check: C-417 ETACS-ECU connector

Q. Is the check result normal?
Go to Step 9.
Repair or replace the connector.

STEP 9. Check harness between C-417 (terminal No. 5) ETACS-ECU connector and B-110 (terminal No. 2) neutral position switch connector.
note Before checking harness, check intermediate connectors C-04, C-127, B-108 <4N1>, A-16 <4A9> and repair if necessary.

  • Check power supply line for damage.

Q. Is the check result normal?
Go to Step 10.
Repair the damaged harness wire.

STEP 10. Connector check: C-11 AS&G-ECU connector

Q. Is the check result normal?
Go to Step 11.
Repair or replace the connector.

STEP 11. Check harness between B-110 (terminal No. 1) neutral position switch connector and C-11 (terminal No. 28) AS&G-ECU connector.
note Before checking harness, check intermediate connector B-108 <4N1>, A-16 <4A9> and repair if necessary.

  • Check output line for open/short circuit and damage.

Q. Is the check result normal?
Go to Step 12.
Repair the damaged harness wire.

STEP 12. M.U.T.-III diagnosis code

  • Reconfirmation of the diagnosis code.

Q. Is the diagnosis code set?
Replace the AS&G-ECU.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).