42A-ONLY LIFTGATE LOCK DOES NOT WORK.

INSPECTION PROCEDURE : Liftgate does not Open.

caution

Before replacing the ECU, ensure that the input and output signal circuits are normal.

CIRCUIT OPERATION

The ETACS-ECU operates this function in accordance with the input signals below.

Vehicle speed signal (ASC-ECU)
Liftgate lock release handle
Liftgate lock actuator

TECHNICAL DESCRIPTION (COMMENT)

If this function does not work normally, a malfunction of the input signal circuit(s) or ETACS-ECU is suspected.

TROUBLESHOOTING HINTS

Vehicle speed signal (ASC-ECU) error
Malfunction of the liftgate lock release handle
Malfunction of the liftgate lock actuator
Malfunction of ETACS-ECU
Damaged wiring harness and connectors

DIAGNOSIS

Required Special Tools:

MB991223: Harness Set
MB992006: Extra Fine Probe

STEP 1. Checking central door unlocking operation

Check that the central door locking system works normally.

Is the check result normal?

Go to Step 2

Refer to

STEP 2. Using scan tool MB991958, read the CAN bus diagnostic trouble code.

(1)

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.

Connect scan tool MB991958. Refer to GROUP 42B, "How to connect scan tool (M.U.T.-III)

(2) Turn the ignition switch to the "ON" position.

(3) Check whether the CAN bus lines related DTC is set.

(4) Turn the ignition switch to the "LOCK" (OFF) position.

Is the DTC set?

Repair the CAN bus line (Refer to GROUP 54C, CAN bus diagnostics table

Go to Step 3

STEP 3. Using scan tool MB991958, read the ASC-ECU diagnostic trouble code.

(1)

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.

Connect scan tool MB991958. Refer to GROUP 42B, "How to connect scan tool (M.U.T.-III)

(2) Turn the ignition switch to the "ON" position.

(3) Check that the ASC-ECU sets a diagnostic trouble code.

(4) Turn the ignition switch to the "LOCK" (OFF) position.

Is the DTC set?

Diagnose ASC-ECU (Refer to GROUP 35C, Diagnostic Trouble Code Chart

Go to Step 4

STEP 4. Using scan tool MB991958, check data list.

Check the input signals from the liftgate lock release handle.

(1)

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.

Connect scan tool MB991958. Refer to GROUP 42B, "How to connect scan tool (M.U.T.-III)

(2) Turn the ignition switch to the "ON" position.

(3) Check the data list of the ETACS.

Liftgate lock release handle: From OFF to ON

Item No.	Item name	Normal condition
Item 230	Trunk / gate opener	From OFF to ON

(4) Turn the ignition switch to the "LOCK" (OFF) position.

OK: Normal condition is displayed.

Is the check result normal?

Go to Step 5

Refer to

STEP 5. Check ETACS-ECU connector C-413 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Is ETACS-ECU connector C-413 in good condition?

Go to Step 6

Repair or replace the damaged component(s). Refer to GROUP 00E, Harness Connector Inspection

. Verify that the liftgate can be locked and unlocked normally.

STEP 6. Check the liftgate lock actuator.

Remove the liftgate lock actuator. The illustration shows when the liftgate lock actuator is viewed from inside the liftgate. Refer to GROUP 42A, Liftgate Handle and Latch <Liftgate upper>

Lever position	Battery connection	Lever operation
At the "SET" position	Connect terminal 2 to negative battery terminal. Connect terminal 1 to positive battery terminal.	Lever moves from "SET" to "OPEN" position.

Is the liftgate lock actuator normal?

Go to Step 7

Replace the liftgate lock actuator. Verify that the liftgate can be locked and unlocked normally.

STEP 7. Check the ground circuit to the liftgate lock actuator. Measure the resistance at liftgate lock actuator connector G-10.

(1) Disconnect liftgate lock actuator connector G-10 and measure the resistance on the wiring harness side of the connector.

(2) Measure the resistance value between terminal 2 and ground.

The resistance should be 2 ohms or less.

Is the measured resistance 2 ohms or less?

Go to Step 9

Go to Step 8

STEP 8. Check the wiring harness between liftgate lock actuator connector G-10 (terminal 2) and ground.

Check the power supply line for open circuit and short circuit.

note	Also check intermediate connector G-23 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector G-23 is damaged, repair or replace the damaged component(s) as described in GROUP 00E, Harness Connector Inspection .

Is the wiring harness between liftgate lock actuator connector G-10 (terminal 2) and ground in good condition?

No action is necessary and testing is complete.

The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify that the liftgate can be locked and unlocked normally.

STEP 9. Check the wiring harness between ETACS-ECU connector C-413 (terminal 1) and liftgate lock actuator connector G-10 (terminal 1).

Check the power supply line for open circuit and short circuit.

note	Also check intermediate connector G-23 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector G-23 is damaged, repair or replace the damaged component(s) as described in GROUP 00E, Harness Connector Inspection .

Is the wiring harness between ETACS-ECU connector C-413 (terminal 1) and liftgate lock actuator connector G-10 (terminal 1) in good condition?

Go to Step 10

STEP 10. Retest the system.

Check that the liftgate can be locked and unlocked normally.

Is the check result normal?

No action is necessary and testing is complete.

Replace the ETACS-ECU. Check that the liftgate can be locked and unlocked normally.