Input Signal Chart and Inspection Procedure
INPUT SIGNAL CHARTCAUTION: During diagnosis, a diagnostic trouble code associated with other system may be set when the ignition switch is turned on with connector(s) disconnected. On completion, confirm all systems for diagnostic trouble code(s). If diagnostic trouble code(s) are set, erase them all.
Trouble symptom
The liftgate lock release handle signal is not received.
INPUT SIGNAL PROCEDURES
INSPECTION PROCEDURE: The liftgate lock release handle signal is not received.
CAUTION: Before replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
Liftgate Lock Release Handle Circuit (Part 1):
Liftgate Lock Release Handle Circuit (Part 2):
COMMENTS ON TROUBLE SYMPTOM
Input signal from the liftgate lock release handle is used to operate the central door locking function. If the signal is abnormal, the central door locking function will not work normally.
PROBABLE CAUSES
- Malfunction of the liftgate lock release handle
- Malfunction of ETACS-ECU
- Damaged wiring harness and connectors
DIAGNOSTIC PROCEDURE
Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
- 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. Check liftgate lock release handle connector F-33 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is liftgate lock release handle connector F-33 in good condition?
YES : Go to Step 2.
NO : Repair or replace the damaged component(s). Refer to General (Electrical), Harness Connector Inspection. Repair the liftgate lock release handle. If the liftgate lock release handle operates normally, a correct signal is sent from the liftgate lock release handle.
STEP 2. Check the liftgate lock release handle.
Remove the liftgate lock release handle. Refer to Liftgate Handle and Latch. Then check continuity between the switch terminals.
Q: Is the liftgate lock release handle in good condition?
YES : Go to Step 3.
NO : Repair the liftgate lock release handle. If the liftgate lock release handle operates normally, a correct signal is sent from the liftgate lock release handle.
STEP 3. Check the ground circuit to the liftgate lock release handle. Measure the resistance at liftgate lock release handle connector F-33.
1. Disconnect liftgate lock release handle connector F-33 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.
Q: Is the measured resistance 2 ohms or less?
YES : Go to Step 5.
NO : Go to Step 4.
STEP 4. Check the wiring harness between liftgate lock release handle connector F-33 (terminal 2) and ground.
- Check the ground line for open circuit and short circuit.
NOTE: Also check intermediate connector F-31 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector F-31 is damaged, repair or replace the damaged component(s) as described in General (Electrical), Harness Connector Inspection.
Q: Is the wiring harness between liftgate lock release handle connector F-33 (terminal 2) and ground in good condition?
YES : No action is necessary and testing is complete.
NO : 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. If the liftgate lock release handle operates normally, a correct signal is sent from the liftgate lock release handle.
STEP 5. Check ETACS-ECU connector C-313 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is ETACS-ECU connector C-313 in good condition?
YES : Go to Step 6.
NO : Repair or replace the damaged component(s). Refer to General (Electrical), Harness Connector Inspection. If the liftgate lock release handle operates normally, a correct signal is sent from the liftgate lock release handle.
STEP 6. Check the wiring harness between liftgate lock release handle connector F-33 (terminal 1) and ETACS-ECU connector C-313 (terminal 14).
- Check the power supply line for open circuit and short circuit.
NOTE: Also check intermediate connector D-15, F-30 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector D-15, F-30 is damaged, repair or replace the damaged component(s) as described in General (Electrical), Harness Connector Inspection.
Q: Is the wiring harness between liftgate lock release handle connector F-33 (terminal 1) and ETACS-ECU connector C-313 (terminal 14) in good condition?
YES : Go to Step 7.
NO : 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. If the liftgate lock release handle operates normally, a correct signal is sent from the liftgate lock release handle.
STEP 7. Using scan tool MB991958, check data list.
Check the signals related to the liftgate lock release handle operation.
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 Keyless Operation System (KOS), "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
4. Turn the ignition switch to the "LOCK" (OFF) position.
OK: Normal condition is displayed.
Q: Is the check result normal?
YES : No action is necessary and testing is complete.
NO : Replace the ETACS-ECU. If the liftgate lock release handle operates normally, a correct signal is sent from the liftgate lock release handle.