Inspection Procedure O-7
The ETACS-ECU does not receive any signal from the door lock switch (incorporated in power window main switch and power window sub switch).Door Lock Switch Input Circuit Part 1:
Door Lock Switch Input Circuit Part 2:
CIRCUIT OPERATION
The ETACS-ECU operates the central door locking system according to signal from the door lock switch.
TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the doors are not locked or unlocked. If the signal is not normal, the power window main switch, power window sub switch or the ETACS-ECU may be defective.
TROUBLESHOOTING HINTS
- The power window main switch or power window sub switch (door lock switch) may be defective.
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector.
- The ETACS-ECU may be defective.
DIAGNOSIS
Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991911: M.U.T.-III Main Harness B
STEP 1. Check the input signal (by using the pulse check mode of the monitor).
Check the input signals from the door lock switch (incorporated in the power window main switch and power window sub switch).
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 the special tool. Refer to "How to connect SWS monitor ".
2. Operate scan tool MB991958 according to the procedure below to display "Pulse check."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "Pulse Checking."
3. Check that scan tool MB991958 sounds when the door lock switch (incorporated in the power window main switch and power window sub switch) is operated.
Q: When the door lock switch (incorporated in the power window main switch and power window sub switch) is operated, does the scan tool MB991958 sound?
YES
NO
NO
STEP 2. Check power window main switch connector E-05 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is power window main switch connector E-05 in good condition?
YES: Go to Step 3.
NO: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. If the central door locking system works normally, input signal from the door lock switch should be normal.
STEP 3. Check the door lock switch (power window main switch).
Remove the power window main switch. Then check continuity between the switch terminals.
Q: Is the door lock switch (power window main switch) in good condition?
YES: Go to Step 4.
NO: Replace the power window main switch. If the central door locking system works normally, input signal from the door lock switch should be normal.
STEP 4. Check the ground circuit to the power window main switch. Measure the resistance at power window main switch connector E-05.
1. Disconnect power window main switch connector E-05 and measure the resistance available at the wiring harness side of the connector.
2. Measure the resistance value between terminal 12 and ground.
- The resistance should equal 2 ohms or less.
Q: Is the measured resistance 2 ohms or less?
YES: Go to Step 6.
NO: Go to Step 5.
STEP 5. Check the wiring harness between power window main switch E-05 (terminal 8) and ground.
NOTE: Also check intermediate connector C-17 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connectors C-17 is damaged, repair or replace the damaged component(s) as described in Harness Connector Inspection.
Q: Is the wiring harness between power window main switch connector E-05 (terminal 8) 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 central door locking system works normally, input signal from the door lock switch should be normal.
STEP 6. Check ETACS-ECU connector C-227 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is ETACS-ECU connector C-227 in good condition?
YES: Go to Step 7.
NO: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. If the central door locking system works normally, input signal from the door lock switch should be normal.
STEP 7. Check the wiring harness between power window main switch connector E-05 (terminal 5 and 13) and ETACS-ECU connector C-227 (terminal 42 and 34).
NOTE: Also check intermediate connector C-17 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connectors C-17 is damaged, repair or replace the damaged component(s) as described in Harness Connector Inspection.
Q: Is the wiring harness between power window main switch connector E-05 (terminal 5 and 13) and ETACS-ECU connector C-227 (terminal 42 and 34) in good condition?
YES: Replace the ETACS-ECU. If the central door locking system works normally, input signal from the door lock switch should be normal.
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 central door locking system works normally, input signal from the door lock switch should be normal.
STEP 8. Check power window sub switch connector E-19 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is power window sub switch connector E-19 in good condition?
YES: Go to Step 9.
NO: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. If the central door locking system works normally, input signal from the door lock switch should be normal.
STEP 9. Check the door lock switch (power window sub switch).
Remove the power window sub switch. Then check continuity between the switch terminals.
Q: Is the door lock switch (power window sub switch) in good condition?
YES: Go to Step 10.
NO: Replace the power window sub switch. If the central door locking system works normally, input signal from the door lock switch should be normal.
STEP 10. Check the ground circuit to the power window sub switch. Measure the resistance at power window sub switch connector E-19.
1. Disconnect power window sub switch connector E-19 and measure the resistance available at the wiring harness side of the connector.
2. Measure the resistance value between terminal 4 and ground.
- The resistance should equal 2 ohms or less.
Q: Is the measured resistance 2 ohms or less?
YES: Go to Step 12.
NO: Go to Step 11.
STEP 11. Check the wiring harness between power window sub switch E-19 (terminal 4) and ground.
NOTE: Also check intermediate connector C-110 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connectors C-110 is damaged, Repair or replace the damaged component(s) as described in Harness Connector Inspection.
Q: Is the wiring harness between power window sub switch connector E-19 (terminal 4) 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 central door locking system works normally, input signal from the door lock switch should be normal.
STEP 12. Check ETACS-ECU connector C-227 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is ETACS-ECU connector C-227 in good condition?
YES: Go to Step 13.
NO: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. If the central door locking system works normally, input signal from the door lock switch should be normal.
STEP 13. Check the wiring harness between power window sub switch connector E-14 (terminal 3 and 2) and ETACS-ECU connector C-227 (terminal 33 and 34).
NOTE: Also check intermediate connector C-110 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connectors C-110 is damaged, Repair or replace the damaged component(s) as described in Harness Connector Inspection.
Q: Is the wiring harness between power window sub switch connector E-19 (terminal 3 and 2) and ETACS-ECU connector C-227 (terminal 33 and 34) in good condition?
YES: Replace the ETACS-ECU. If the central door locking system works normally, input signal from the door lock switch should be normal.
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 central door locking system works normally, input signal from the door lock switch should be normal.