Inspection Procedure M-5
The ETACS-ECU does not Receive Any Signal from the Driver's Door Lock Key Cylinder SwitchDoor Lock Key Cylinder Switch Input Circuit:
Connectors:
CIRCUIT OPERATION
The ETACS-ECU operates the central door locking system according to signal from the driver's door lock key cylinder switch.
TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the systems, which are described in "CIRCUIT OPERATION", do not work normally.
TROUBLESHOOTING HINTS
- Malfunction of the driver's door lock key cylinder switch
- Malfunction of the ETACS-ECU
- Damaged harness wires or connectors
DIAGNOSIS
Required Special Tools:
- MB991223: Test Harness Set
- MB991502: Scan Tool (MUT-II)
STEP 1. Check which door lock key cylinder switch is defective.
Q: Which door lock key cylinder switch does not send a signal to the ECU?
Driver's door : Go to Step 2.
Front passenger's door : Go to Step 8.
STEP 2. Check the driver's door lock key cylinder switch.
Disconnect door lock key cylinder switch (LH) connector E-01.
Then check continuity between the switch terminals.
Q: Is the driver's door lock key cylinder switch in good condition?
YES: Go to Step 3.
NO: Replace the driver's door lock key cylinder switch. If the systems, which are described in "CIRCUIT OPERATION", work normally, the input signal from the driver's door lock key cylinder switch should be normal.
STEP 3. Measure at driver's door lock key cylinder switch connector E-01 in order to check the ground circuit to the driver's door lock key cylinder switch.
1. Disconnect driver's door lock key cylinder switch connector E-01, and measure at the harness side.
2. Measure the resistance value between terminal 2 and ground.
- The measured value should be 2 Ohm or less.
Q: Does the measured resistance value correspond with this range?
YES: Go to Step 6.
NO: Go to Step 4.
STEP 4. Check driver's door lock key cylinder switch connector E-01 for damage.
Q: Is driver's door lock key cylinder switch connector E-01 in good condition?
YES: Go to Step 5.
NO: Repair or replace the connector. Refer to Harness Connector Inspection. If the systems, which are described in "CIRCUIT OPERATION", work normally, the input signal from the driver's door lock key cylinder switch should be normal.
STEP 5. Check the wiring harness between driver's door lock key cylinder switch connector E-01 and ground.
NOTE: Also check intermediate connector C-17. If intermediate connectors C-17 is damaged, repair or replace the connector as described in Harness Connector Inspection.
Q: Is the wiring harness between driver's door lock key cylinder switch connector E-01 and ground in good condition?
YES: No action to be taken.
NO: Repair the wiring harness. If the systems, which are described in "CIRCUIT OPERATION", work normally, the input signal from the driver's door lock key cylinder switch should be normal.
STEP 6. Check driver's door lock key cylinder switch connector E-01 and ETACS-ECU connector C-227 for damage.
Q: Are driver's door lock key cylinder switch connector E-01 and ETACS-ECU connector C-227 in good condition?
YES: Go to Step 7.
NO: Repair or replace the connector. Refer to Harness Connector Inspection. If the systems, which are described in "CIRCUIT OPERATION", work normally, the input signal from the driver's door lock key cylinder switch should be normal.
STEP 7. Check the wiring harness between driver's door lock key cylinder switch connector E-01 and ETACS-ECU connector C-227.
NOTE: Also check intermediate connector C-17. If intermediate connectors C-17 is damaged, repair or replace the connector as described in Harness Connector Inspection.
Q: Is the wiring harness between driver's door lock key cylinder switch connector E-01 and ETACS-ECU connector C-227 in good condition?
YES: Replace the ETACS-ECU. If the systems, which are described in "CIRCUIT OPERATION", work normally, the input signal from the driver's door lock key cylinder switch should be normal.
NO: Repair the wiring harness. If the systems, which are described in "CIRCUIT OPERATION", work normally, the input signal from the driver's door lock key cylinder switch should be normal.
STEP 8. Check the front passenger's door lock key cylinder switch.
Disconnect door lock key cylinder switch (RH) connector E-12.
Then check continuity between the switch terminals.
Q: Is the front passenger's door lock key cylinder switch in good condition?
YES: Go to Step 9.
NO: Replace the front passenger's door lock key cylinder switch. If the systems, which are described in "CIRCUIT OPERATION", work normally, the input signal from the front passenger's door lock key cylinder switch should be normal.
STEP 9. Measure at door lock key cylinder switch (RH) connector E-12 in order to check the ground circuit to the front passenger's door lock key cylinder switch.
1. Disconnect front passenger's door lock key cylinder switch connector E-12, and measure at the harness side.
2. Measure the resistance value between terminal 2 and ground.
- The measured value should be 2 Ohm or less.
Q: Does the measured resistance value correspond with this range?
YES: Go to Step 12.
NO: Go to Step 10.
STEP 10. Check front passenger's door lock key cylinder switch connector E-12 for damage.
Q: Is front passenger's door lock key cylinder switch connector E-12 in good condition?
YES: Go to Step 11.
NO: Repair or replace the connector. Refer to Harness Connector Inspection. If the systems, which are described in "CIRCUIT OPERATION", work normally, the input signal from the front passenger's door lock key cylinder switch should be normal.
STEP 11. Check the wiring harness between front passenger's door lock key cylinder switch connector E-12 and ground.
NOTE: Also check intermediate connector C-110. If intermediate connectors C-110 is damaged, repair or replace the connector as described in Harness Connector Inspection.
Q: Is the wiring harness between front passenger's door lock key cylinder switch connector E-12 and ground in good condition?
YES: No action to be taken.
NO: Repair the wiring harness. If the systems, which are described in "CIRCUIT OPERATION", work normally, the input signal from the front passenger's door lock key cylinder switch should be normal.
STEP 12. Check front passenger's door lock key cylinder switch connector E-12 and ETACS-ECU connector C-227 for damage.
Q: Are front passenger's door lock key cylinder switch connector E-12 and ETACS-ECU connector C-227 in good condition?
YES: Go to Step 13.
NO: Repair or replace the connector. Refer to Harness Connector Inspection. If the systems, which are described in "CIRCUIT OPERATION", work normally, the input signal from the front passenger's door lock key cylinder switch should be normal.
STEP 13. Check the wiring harness between front passenger's door lock key cylinder switch connector E-12 and ETACS-ECU connector C-227.
NOTE: Also check intermediate connector C-110. If intermediate connectors C-110 is damaged, repair or replace the connector as described in Harness Connector Inspection.
Q: Is the wiring harness between front passenger's door lock key cylinder switch connector E-12 and ETACS-ECU connector C-227 in good condition?
YES: Replace the ETACS-ECU. If the systems, which are described in "CIRCUIT OPERATION", work normally, the input signal from the front passenger's door lock key cylinder switch should be normal.
NO: Repair the wiring harness. If the systems, which are described in "CIRCUIT OPERATION", work normally, the input signal from the front passenger's door lock key cylinder switch should be normal.