Inspection Procedure D-1

Power Window Relay Circuit:

Connectors:

CIRCUIT OPERATION
- The power window relay is controlled by the front-ECU and the ETACS-ECU.
- The front-ECU operates the power window relay if the front-ECU receives request signal from the ETACS-ECU, or ignition switch (IG1) signal from the front-ECU itself.

TECHNICAL DESCRIPTION (COMMENT)
The power window relay or the front-ECU may be defective.

TROUBLESHOOTING HINTS
- Malfunction of the power window relay
- Malfunction of the front-ECU
- Damaged harness wires or connectors

DIAGNOSIS
Required Special Tool:
MB991223: Test Harness Set







STEP 1. Check the power window relay.
If the power window relay is damaged, replace it.
The power windows should work normally.
If the power window relay is not damaged, go to Step 2.




STEP 2. Check the power window relay power supply circuit at the power window relay connector A-04X.
1. Disconnect the power window relay connector A-04X and measure at the relay box side.
2. Voltage between terminal 5 and ground.
- Voltage should be approximately 12 volts (battery positive voltage).
3. Voltage between terminal 1 and ground.
- Voltage should be approximately 12 volts (battery positive voltage).
If one of the checks above does not show approximately 12 volts, go to Step 3.
If neither of the checks above shows approximately 12 volts, go to Step 5.




STEP 3. Check the power window connector A-04X for damage.
If the power window connector A-04X is damaged, repair or replace it. Refer to Harness Connector Inspection.
The power windows should work normally.
If the connector is in good condition, go to Step 4.




STEP 4. Check the harness wire between power window relay connector A-04X and fusible link (4).
If the harness wire between power window relay connector A-04X and fusible link (4) is damaged, repair it.
The power windows should work normally.




STEP 5. Check the power window relay connector A-04X and front-ECU connector A-09X for damage.
If the power window relay connector A-04X and front-ECU connector A-09X are damaged, repair or replace them. Refer to Harness Connector Inspection.
The power windows should work normally.
If the connectors are in good condition, go to Step 6.




STEP 6. Check the harness wire between power window relay connector A-04X and front-ECU connector A-09X.
If the harness wire between power window relay connector A-04X and front-ECU connector A-09X is damaged, repair it.
The power windows should work normally.
If the harness wire is in good condition, go to Step 7.







STEP 7. Check the power window relay connector A-04X and power window main switch connector E-12 for damage.
If the power window relay connector A-04X and power window main switch connector E-12 are damaged, repair or replace them. Refer to Harness Connector Inspection. The power windows should work normally.
If the connectors are in good condition, go to Step 8.










STEP 8. Check the harness wires between power window relay connector A-04X and power window main switch connector E-12.

NOTE: After checking intermediate connector C-89 and C-91, check the wires. If intermediate connector C-89 and C-91 are damaged, repair or replace them. Refer to Harness Connector Inspection.

If the harness wires between power window relay connector A-04X and power window main switch connector E-12 are damaged, repair them.
The power windows should work normally.

If the harness wires are in good condition, replace the front-ECU.
The power windows should work normally.