Faulty Signal
Faulty signal
Checking the signal from the control switch for the child lock switch
- Ignition on
- Read the status of the control switch for the child lock from both rear doors.
Activate and deactivate the power child locks.
The status of both doors should change at the same time as the function is engaged / disengaged.
The fault is permanent if the status does not change.
If the status changes, this indicates an intermittent fault, i.e. the fault was present previously but is not active at the moment.
Continue - Checking the function of the lock mechanism
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Checking the function of the lock mechanism
- Ignition on
Activate and deactivate the power child locks. Check that the door can be opened from the inside when unlocked and that it cannot be opened when locked.
Is the function OK?
Yes - Checking the signal from the switches in the rear doors
No - Checking cable and component
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Checking the signal from the switches in the rear doors
Note! Only fault-trace the circuit of the door displaying the faulty value.
Check the switch in the lock mechanism. Check for a short-circuit. Check by measuring the resistance between terminals #6 and #7 on the connector for the lock mechanism.
Check the resistance between terminals #6 and #7 on the lock mechanism. The resistance must be infinite or near 0 ohm depending on the position of the switch.
Left rear door
Check the signal cable between rear electronic module (REM) connector terminal #50 (#C10) and terminal #7 on the lock mechanism. Check for a short-circuit to ground. The lock mechanism is jammed if no fault is found in the cable or the switch.
Right rear door
Check the signal cable between rear electronic module (REM) connector terminal #4 (#D4) and lock mechanism terminal #7. Check for a short-circuit to ground. The lock mechanism is jammed if no fault is found in the cable or the switch.
Remedy as necessary.
Other information
- Connecting the breakout box Connecting The Breakout Box, Rear Electronic Module (REM)
- Signal specification, Rear electronic module (REM) Signal Specification, Rear Electronic Module (REM)
- Lock mechanism front side door, replacing Lock Mechanism Front Side Door, Replacing
- Disconnecting the rear electronic module (REM): Integrated relay / fusebox cargo compartment / rear electronic module, replacing Integrated Relay/Fusebox Cargo Compartment/Rear Electronic Module (REM), Replacing
- Checking wiring and terminals Checking Wiring And Terminals
Continue - Verification
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Checking cable and component
Note! Only fault-trace the circuit of the door displaying the faulty value.
Check the connectors for the lock mechanism and the rear electronic module (REM). Check for contact resistance and oxidation.
Left rear door
Check the wiring between the lock mechanism connector terminals #3 and #8 and the relay terminals #2 and #4 for the child lock. Check for an open-circuit. Check for a short-circuit to ground. Check for a short-circuit to supply voltage.
Check the wiring between the lock mechanism connector terminals #3 and #5 and the power window switch. Check for an open-circuit. Check for a short-circuit to ground. Check for a short-circuit to supply voltage.
Check the cable between relay terminal #1 for the child lock and rear electronic module (REM) terminal #27 (#A27). Check for an open-circuit. Check for a short-circuit to ground. Check for a short-circuit to supply voltage.
Hint: Remove the relay for power child locks while checking the lock motors. If the function is OK when the relay is removed it means that there is a fault in the relay or in the circuit for controlling the relay.
Right rear door
Check the wiring between the lock mechanism connector terminals #3 and #8 and the relay terminals #2 and #4 for the child lock. Check for an open-circuit. Check for a short-circuit to ground. Check for a short-circuit to supply voltage.
Check the wiring between the lock mechanism connector terminals #3 and #5 and the power window switch. Check for an open-circuit. Check for a short-circuit to ground. Check for a short-circuit to supply voltage.
Check the cable between relay terminal #1 for the child lock and rear electronic module (REM) terminal #24 (#B24). Check for an open-circuit. Check for a short-circuit to ground. Check for a short-circuit to supply voltage.
Hint: Remove the relay for power child locks while checking the lock motors. If the function is OK when the relay is removed it means that there is a fault in the relay or in the circuit for controlling the relay.
The lock mechanism is jammed if no fault is found in the wiring.
Remedy as necessary.
Other information
- Connecting the breakout box Connecting The Breakout Box, Rear Electronic Module (REM)
- Signal specification, Rear electronic module (REM) Signal Specification, Rear Electronic Module (REM)
- Lock mechanism front side door, replacing Lock Mechanism Front Side Door, Replacing
- Disconnecting the rear electronic module (REM): Integrated relay / fusebox cargo compartment / rear electronic module, replacing Integrated Relay/Fusebox Cargo Compartment/Rear Electronic Module (REM), Replacing
- Checking wiring and terminals Checking Wiring And Terminals
Continue - Verification
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Verification
Verification
Hint: After carrying out the repair, check that the fault has been remedied.
- Ignition off
- Reinstall the connectors, components etc.
- Ignition on
- Read the status of the control switch for the child lock from both rear doors.
Activate and deactivate the power child locks.
The status of both doors should change at the same time as the function is engaged / disengaged.
Is the status OK?
Yes - VERIFIED
No - VERIFICATION FAILED
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VERIFICATION FAILED - Fault-tracing information
VERIFIED - FAULT FOUND
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Fault-tracing information
Information
Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.
Do you want to exit fault-tracing?
Yes - Exit fault-tracing
No - Attempt New Test
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Attempt New Test - Checking the signal from the control switch for the child lock switch
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