Inspection Procedure 10

Inspection Procedure 10: Driver's door unlock sensor does not work.

CAUTION: Before replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.

Unlock Sensor (Front Door: LH) Circuit:

TROUBLESHOOTING HINTS
- Malfunction of the exterior transmitter antenna assembly (driver's side)
- Malfunction of the unlock sensor (front door: LH)
- Damaged wiring harness and connectors
- Malfunction of the KOS-ECU

DIAGNOSIS

Required Special Tools:
- MB992006: Extra fine probe
- MB991223: Harness set
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicles Communication Interface (V.C.I.)
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A

STEP 1. Using scan tool MB991958, read the diagnostic trouble code.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.






1. Connect scan tool MB991958. Refer to "How to connect scan tool (M.U.T.-III)." How To Connect The Scan Tool (M.U.T.-III)
2. Turn the ignition switch to the "ON" position.
3. Check whether the KOS-ECU related DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC set?

YES: Diagnose the KOS-ECU. (Refer to Diagnostic Trouble Code Chart). Diagnostic Trouble Code Descriptions

NO: Go to Step 2.

STEP 2. Check KOS-ECU connector C-05 and unlock sensor (front door: LH) connector E-18 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are KOS-ECU connector C-05 and unlock sensor (frontdoor: LH) connector E-18 in good condition?

YES: Go to Step 3.

NO: Repair or replace the damaged component(s). Refer to general (Electrical), Harness Connector Inspection. Check that the driver.s door unlock sensor works normally.

STEP 3. Check the wiring harness between the KOS-ECU connector C-05 (terminal Nos. 24, 36) and unlock sensor(front door: LH) connector E-18 (terminal Nos. 4, 2), and between unlock sensor (front door: LH) connector E-18(terminal No. 6) and ground for open circuit.

1. Disconnect KOS-ECU connector C-05 and unlock sensor(front door: LH) connector E-18, and check the wiring harness.




2. Check the wiring harness between KOS-ECU connector C-05 (terminal No.24) and unlock sensor (front door: LH)connector E-18 (terminal No.4).

OK: Continuity exists (2 Ohms or less)




3. Check the wiring harness between KOS-ECU connector C-05 (terminal No.36) and unlock sensor (front door: LH)connector E-18 (terminal No.2).

OK: Continuity exists (2 Ohms or less)




4. Check the wiring harness between unlock sensor (front door: LH) connector E-18 (terminal No.6) and ground.

OK: Continuity exists (2 Ohms or less)

Q: Is the wiring harness between KOS-ECU connector C-05 (terminal Nos. 24, 36) and unlock sensor (front door:LH) connector E-18 (terminal Nos. 4, 2), and between unlock sensor (front door: LH) connector E-18 (terminal No. 6) and ground in good condition?

YES: Go to Step 4.

NO (KOS-ECU connector C-05 terminal No.24 - unlock sensor (front door: LH) connector E-18 terminal No.4.) : Repair the wiring harness between KOS-ECU connector C-05 (terminal No.24) and unlock sensor(front door: LH) connector E-18 (terminal No.4).

NO (KOS-ECU connector C-05 terminal No.36 - unlock sensor (front door: LH) connector E-18 terminal No.2.) : Repair the wiring harness between KOS-ECU connector C-05 (terminal No.36) and unlock sensor(front door: LH) connector E-18 (terminal No.2).

NO (unlock sensor (front door: LH) connector E-18terminal No.6 - ground.) : Repair the wiring harness between unlock sensor (front door: LH) connector E-18 (terminal No.6) and ground.

STEP 4. Check the wiring harness between the unlock sensor (front door: LH) connector E-18 (terminal Nos. 4, 2,6) and the ground for short circuit.

1. Disconnect unlock sensor (front door: LH) connector E-18,and check the wiring harness.




2. Check the wiring harness between unlock sensor (frontdoor: LH) connector E-18 (terminal No. 4) and ground

OK: No continuity




3. Check the wiring harness between unlock sensor (frontdoor: LH) connector E-18 (terminal No. 2) and ground

OK: No continuity




4. Check the wiring harness between unlock sensor (frontdoor: LH) connector E-18 (terminal No.6) and ground.

OK: No continuity

Q: Is the wiring harness between unlock sensor (frontdoor: LH) connector E-18 (terminal Nos. 4, 2, 6) and the ground in good condition?

YES: Go to Step 5.

NO [unlock sensor (front door: LH) connector E-18 terminal No.4 - ground.] : Repair the wiring harness between unlock sensor (front door: LH) connector E-18 (terminal No.4) and ground.

NO [unlock sensor (front door: LH) connector E-18terminal No.2 - ground.] : Repair the wiring harness between unlock sensor (front door: LH) connector E-18 (terminal No.2) and the ground.

NO [unlock sensor (front door: LH) connector E-18terminal No.6 - ground.] : Repair the wiring harness between unlock sensor (front door: LH) connector E-18 (terminal No.6) and the ground.

STEP 5. KOS communication test

Using scan tool (M.U.T-III), perform the antenna communication test to check that the exterior transmitter antenna (driver's side) communicates normally (Refer to ID Codes Registration Procedures)

Q: Is the check result normal?

YES: Go to Step 6.

NO: Perform troubleshooting for the diagnostic trouble code No. B240A. B240A

STEP 6. Check of the troubles

Operate the unlock sensor (front door: LH) and check that the door can be locked.

Q: Is the check result normal?

YES: The diagnosis is complete.

NO: Replace KOS-ECU and register the ID codes (Refer to ID Code Registration Necessity Judgment Table).