Inspection Procedure 5

Some Doors do not Lock or Unlock













CIRCUIT OPERATION
When the door lock actuator receives the lock or unlock signal from the ETACS-ECU, the actuator will lock or unlock the door.

TECHNICAL DESCRIPTION (COMMENT)
The cause may be a malfunction of the door lock actuator or of a wiring harness or connector.

TROUBLESHOOTING HINTS
- Malfunction of the door lock actuator
- Damaged wiring harness or connector

DIAGNOSIS
Required Special Tool:
- MB991223: Harness Set
- MB991502: Scan Tool (MUT-II)
- MB991529: Diagnostic Trouble Code Check Harness

STEP 1. Choose method of ETACS-ECU input signal check

Q: Is the ETACS-ECU input signal check performed by the scan tool MB991502 or a voltmeter?
By Scan tool MB991502 :Go to Step 2.
By a Voltmeter [Front door lock actuator check] :Go to Step 3.
By a Voltmeter [Rear door lock actuator check] :Go to Step 4.
By a Voltmeter [Liftgate lock actuator check] : Go to Step 5.

STEP 2. Check the input signal (by using pulse check).
Check the ETACS-ECU input signal (front and rear door lock actuator and rear door lock actuator) by using scan tool MB991502.

CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.







1. Connect scan tool MB991502 to the data link connector (16-pin).
2. Check that the tone alarm of the scan tool MB991502 sounds when the front door lock actuator, rear door lock actuator or liftgate lock actuator is operated (lock/unlock).

Q: Does the tone alarm of scan tool MB991502 sound when the input signal enters?
YES: Replace the ETACS-ECU and then go to Step 11.
NO (Front door lock actuator input signal) : Go to Step 6.
NO (Rear door lock actuator input signal) : Go to Step 7.
NO (Liftgate lock actuator input signal) : Go to Step 8.

STEP 3. Check the ETACS-ECU input signal from the front door lock actuator (by using a voltmeter).







1. Use special tool MB991529 to connect a voltmeter between ground terminal 4 or 5 and ETACS-ECU terminal 9 of the data link connector.
2. Check that the voltmeter indicator deflects once when front door lock actuator is operated (lock/unlock).

Q: Does the voltmeter indicator deflect?
YES: Replace the ETACS-ECU and then go to Step 11.
NO: Go to Step 6.

STEP 4. Check the input signal from the rear door lock actuator (by using a voltmeter).







1. Use special tool MB991529 to connect a voltmeter between ground terminal 4 or 5 and ETACS-ECU terminal 9 of the data link connector.
2. Check that the voltmeter indicator deflects once when the rear door lock actuator is operated (lock/unlock).

Q: Does the voltmeter indicator deflect?
YES: Replace the ETACS-ECU and then go to Step 11.
NO: Go to Step 7.

STEP 5. Check the input signal from the liftgate lock actuator (by using a voltmeter).







1. Use special tool MB991529 to connect a voltmeter between ground terminal 4 or 5 and ETACS-ECU terminal 9 of the data link connector.
2. Check that the voltmeter indicator deflects once when the liftgate lock actuator is operated (lock/unlock).

Q: Does the voltmeter indicator deflect?
YES: Replace the ETACS-ECU and then go to Step 11.
NO: Go to Step 8 .

STEP 6. Check the front door lock actuator switch.







1. Remove the door latch assembly.













2. Follow the table to check the front door lock actuator operation (lock/unlock).

Q: Is the front door lock actuator switch damaged?
YES: Replace the door latch assembly, then go to Step 11.
NO: Go to Step 9.

STEP 7. Check the rear door lock actuator.







1 Remove the door lock key cylinder switch







2. Follow the table to check the rear door lock actuator (lock/ unlock).

Q: Is the rear door lock actuator damaged?
YES: Replace the door lock actuator assembly, go to Step 11.
NO: Go to Step 9.

STEP 8. Check the liftgate lock actuator







1. Remove the liftgate lock key cylinder.







2. Follow the table to check the liftgate lock actuator operation (lock/unlock).

Q: Is the liftgate lock actuator damaged?
YES: Replace liftgate lock actuator, then go to Step 11.
NO: Go to Step 9.






















STEP 9. Check ETACS-ECU connector D-10 [Vehicles without keyless entry system] or D-27 [Vehicles with keyless entry system] and door lock actuator connectors F-09, F-12, F-21, F-24 and G-04 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

NOTE: After inspecting intermediate connector C-01, C-12, C-39, E-01, E-18, E-31 or E-42 inspect the wire. If junction block connector C-01, C-12, C-39, E-01, E-18, E-31 or E-42 is damaged, repair or replace damaged component. Refer to Harness Connector Inspection. Then go to Step 11.

Q: Are the connectors in good condition?
YES: Go to step 10.
NO: Repair or replace the damaged components. Refer to Harness Connector inspection. Then go to Step 11.






















STEP 10.Check the harness wires between ETACS-ECU connector D-10 (terminal No.21, 23 and 24) [Vehicles without keyless entry system] or D-27 (terminal No.41, 42, 43 and 45) [Vehicles with keyless entry system] and door lock actuator connector F-09 (terminal No.1 and 2)/F-12 (terminal No.2, 4 and 6)/F-21 (terminal No.1 and 2)/F-24 (terminal No.4 and 6)/G-04 (terminal No.1 and 2).

NOTE: After inspecting intermediate connector C-01, C-12, C-39, E-01, E-18, E-31 or E-42 inspect the wire. If junction block connector C-01, C-12, C-39, E-01, E-18, E-31 or E-42 is damaged, repair or replace it. Refer to Harness Connector Inspection. Then go to Step 11.

Q: Are there any damaged harness wires between ETACS-ECU connector D-10 [Vehicles without keyless entry system] or D-27 [Vehicles with keyless entry system] and door lock actuator connectors F-09/F-12/F-21/F-24/G-04?
YES: Repair or replace the harness wire, then go to Step 11.
NO: Go to Step 11.

STEP 11. Retest the system.
Q: Does the door lock function operate normally?
YES: The procedure is complete.
NO: Return to Step 1.