Checking the Lock Function of the Trunk Lid
Checking the lock function of the trunk lid
Checking the lock unit
Check that the lock is not sticking or jammed. Check that the lock unit is correctly installed.
Check that the lock position sensor functions: Open the trunk lid and close the lock manually with the trunk lid open. This can be carried out by pressing a pen against the striker plate. The cargo compartment lighting should go out when locking is complete.
Then unlock using the trunk lid handle button. The lock motor should automatically and audibly return to the starting point when unlocking is complete.
Remedy as necessary.
1. The trunk lid can be unlocked with the handle button and locked mechanically
2. The trunk lid can only be unlocked with the remote control
3. The trunk lid cannot be unlocked with either the remote control or the handle button.
Select one of the above response options.
1 - Fault Found
2 - Button test
3 - Checking fuses
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Button test
Press the button in and check if the text displays ON.
Check that the trunk lid opens when the button is pressed in.
Is the function OK?
Yes - Fault Found
Not OK - Checking the license plate lighting
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Checking the license plate lighting
- Ignition on.
Does the license plate lighting function?
Yes - Checking the signal cable for the lock button
Not OK - Checking the ground lead for the lock button
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Checking the signal cable for the lock button
Disconnect the connector at the license plate lighting. Check for contact resistance and oxidation.
Check the cable between rear electronic module (REM) connector terminal #D7 and the license plate lighting terminal #1. Check for an open-circuit. In particular check the intermediate connector in the cable harness and the connector in the rear electronic module (REM). Check for oxidation.
Remedy as necessary.
If no fault is detected, ground terminal #1 in the connector for the license plate lighting lamp housing. Then check that the ON is displayed.
If the text ON is not displayed, break the power supply to the rear electronic module (REM).
If the text ON is displayed, replace the lock button.
Other information
- To access and replace the integrated relay / fusebox in the cargo compartment, see Relay/fuse box cargo compartment/Rear electronic module (REM), replacing Integrated Relay/Fusebox Cargo Compartment/Rear Electronic Module (REM), Replacing
- To connect the breakout box, see Connecting the breakout box Connecting the Breakout Box
- To expose the lamp housing for the license plate lighting, see Bulb, number plate lighting, replacing Bulb, Number Plate Lighting, Replacing
- To access and replace the lock button, see Lock mechanism, tailgate, replacing Service and Repair
- Checking wiring and terminals Checking Wiring And Terminals.
Continue - Fault Found
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Checking the ground lead for the lock button
Check the switch at license plate lighting lamp housing terminal #3 and at lock unit terminal #4. Check the intermediate cable for an open-circuit.
Remedy as necessary.
Other information
- To expose the lamp housing for the license plate lighting, see Bulb, number plate lighting, replacing Bulb, Number Plate Lighting, Replacing
- To access and replace the lock button, see Lock mechanism, tailgate, replacing Service and Repair
- Checking wiring and terminals Checking Wiring And Terminals.
Continue - Fault Found
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Checking fuses
Remove fuse 11D/6 from the cargo compartment fusebox.
Check the fuse. Check for contact resistance and oxidation.
Other information
- To access the integrated relay / fusebox in the cargo compartment, see Relay/fuse box cargo compartment/Rear electronic module (REM), replacing Integrated Relay/Fusebox Cargo Compartment/Rear Electronic Module (REM), Replacing
- Checking wiring and terminals Checking Wiring And Terminals.
Is the fuse intact?
OK - Replacing the relay
Not OK - Checking for a short-circuit
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Replacing the relay
Replace the relay for unlocking 2/67 (RMI 20) in the integrated relay / fusebox in the cargo compartment.
At the same time, check the relay base switches. Check for contact resistance and oxidation.
Remedy as necessary.
Other information
- To access the integrated relay / fusebox in the cargo compartment, see Relay/fuse box cargo compartment/Rear electronic module (REM), replacing Integrated Relay/Fusebox Cargo Compartment/Rear Electronic Module (REM), Replacing
- Checking wiring and terminals Checking Wiring And Terminals.
Was a fault detected?
Yes - Fault Found
No - Circuit test
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Circuit test
The fault is caused by an open-circuit in one of the relay circuits in the lock unit. To determine in which circuit the fault is:
Disconnect the connector at the lock unit.
Check the connectors for contact resistance and oxidation.
Measure the resistance between terminals terminal #2 and #4 on the cable connector.
Other information
- To access and replace the lock unit, see Lock mechanism, tailgate, replacing Service and Repair
- Checking wiring and terminals Checking Wiring And Terminals.
The ohmmeter should read 0ohm.
OK - Checking ground lead
Not OK - Circuit test continued
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Circuit test continued
Measure the resistance between terminal #2 and ground and between terminal #4 and ground on the cable connector.
1. The ohmmeter displays an incorrect value between terminal #4 and ground
2. The ohmmeter displays an incorrect value between terminal #2 and ground
3. The ohmmeter displays the correct value.
Select one of the above response options.
1 - Checking ground lead
2 - Checking the power supply
3 - No Fault Found
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Checking ground lead
Check the cable between terminal #2 in the cable connector and ground terminal. Check for an open-circuit.
Check in particular the intermediate connector in the cable harness. Check for contact resistance and oxidation.
Remedy as necessary.
Other information
- Checking wiring and terminals Checking Wiring And Terminals.
Continue - Fault Found
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Checking the power supply
Remove the relay for unlocking 2/67 (RMI 20) from the integrated relay / fusebox in the cargo compartment.
Check the cable between terminal #2 the cable and connector and terminal #3 on the relay base. Check for an open-circuit.
If a fault is detected, check in particular the intermediate connector in the cable harness. Check for contact resistance and oxidation.
If no fault is detected, measure the resistance between terminal #4 in the relay base and ground.
In both cases the ohmmeter should read 0 ohms.
If the value is incorrect, replace the rear electronic module (REM).
Other information
- To access and replace the rear electronic module (REM), see Relay/fuse box cargo compartment/Rear electronic module (REM), replacing Integrated Relay/Fusebox Cargo Compartment/Rear Electronic Module (REM), Replacing.
Continue - Fault Found
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Checking the component
Measure the resistance between pins terminals #2 and #4 on the chassis switch lock unit.
The ohmmeter should read approximately 5 ohm.
If the value is incorrect, replace the lock unit.
Other information
- To access and replace the lock unit, see Lock mechanism, tailgate, replacing Service and Repair.
Was a fault detected?
Yes - Fault Found
No - Checking relay power supply
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Checking relay power supply
Remove the relay for locking 2/67 (RMI 20) from the integrated relay / fusebox in the cargo compartment.
Measure the voltage between terminal #5 in the relay base and ground.
The voltmeter should read battery voltage.
Hint: If the value is OK but the fault remains, connect the connector to the lock module between terminals #3 and #5 in the relay base to force a supply to the locking motor when continuing to take measurements.
Other information
- To access the integrated relay / fusebox in the cargo compartment, see Relay/fuse box cargo compartment/Rear electronic module (REM), replacing Integrated Relay/Fusebox Cargo Compartment/Rear Electronic Module (REM), Replacing.
Does the voltmeter read battery voltage?
Yes - Fault Found
No - Checking for an open-circuit
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Checking for an open-circuit
Check the cable between the fuse holder secondary side (left) and terminal #5 in the relay base. Check for an open-circuit.
Other information
- To access the rear electronic module (REM), see Relay/fuse box cargo compartment/Rear electronic module (REM), replacing Integrated Relay/Fusebox Cargo Compartment/Rear Electronic Module (REM), Replacing
- Checking wiring and terminals Checking Wiring And Terminals.
Continue - Fault Found
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Checking for a short-circuit
Measure the resistance between the fuse holder secondary side (left) and ground.
The ohmmeter should read infinite resistance.
If the value is correct, replace the fuse.
Note! The fault could be intermittent.
If the value is incorrect, fault-trace all affected relay circuits and component wiring for a short-circuit to ground.
Hint: Replace fuse.
If the fuse blows immediately the short-circuit is in the relay power cable.
If the fuse blows when the tailgate is opened the short-circuit is in the power supply cable for the component
Relay supply cable: fuse 11D/6 terminal #5 relay base 2/67.
Component supply cable: terminal #4 relay base 2/67 terminal #2 lock unit.
Other information
- To access the rear electronic module (REM), see Relay/fuse box cargo compartment/Rear electronic module (REM), replacing Integrated Relay/Fusebox Cargo Compartment/Rear Electronic Module (REM), Replacing
- Checking wiring and terminals Checking Wiring And Terminals.
Continue - Fault Found
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