Checking Rear Window Lift
Checking rear window lift
Checking fuse 11C/37 (30A)
- Ignition off.
Check that fuse 11C/37 (30A) is intact.
Is the fuse OK?
Yes - Checking power supply wire
No - Checking the power supply wires
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Checking power supply wire
- Ignition off.
Remove window lift relay from relay holder.
- Relay 2/116 for LH rear door, up.
- Relay 2/118 for LH rear door, down.
- Relay 2/117 for RH rear door, up.
- Relay 2/119 for RH rear door, down.
- Relay 2/120 for child catch.
Remove fuse 11C/37.
Check wire between fuse 11C/37 #2 and relay holder #3 (for each function) for an open circuit as described in Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Install relay and fuse.
Activate relay with switch unit on rear door, up/down.
Additional information:
- To connect the test box, see Connecting the breakout box Connecting the Breakout Box, Central Electronic Module (CEM).
- For information on signals, see Signal specification Pinout Values and Diagnostic Parameters.
Is function OK?
Yes - Verification
No - oxidation
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Checking contact resistance, oxidation
Remove relay and check relay socket contacts for contact resistance and oxidation as described in Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Also check switch 54/20 or 54/21 (LH/RH) for contact resistance and oxidation as described in Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Reassemble relay and switch.
Activate relay with switch unit on rear door, up/down.
If the function is now OK, this means that the fault was probably caused by a faulty contact in the relay socket.
Additional information:
- To access the window lift relay, see Central electronic module (CEM), replacing Central Electronic Module (CEM), Replacing.
Does it work?
Yes - Verification
No - Checking for open circuits from relay to motor
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Checking for open circuits from relay to motor
- Ignition off.
For window lift control rear LH door up, remove window lift relay 2/116 from relay holder. Check wire for open circuit between relay holder #1, switch 54/20 #8, and switch 3/85 #5, as described in Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Also check wire from 3/85 #4 and #6, and motor 6/92 #1 and #2 for open circuit.
For window lift control rear LH door down, remove window lift relay 2/118 from relay holder. Check wire for open circuit between relay holder #1 switch 54/20 #6, and switch 3/85 #3, as described in Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Also check wire from 3/85 #4 and #6, and motor 6/92 #1 and #2.
For window lift control rear RH door up, remove window lift relay 2/117 from relay holder. Check wire for open circuit between relay holder #1, switch 54/21 #8 and switch 3/86 #5, as described in Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Also check wire from 3/86 #4 and #6, and motor 6/93 #1 and #2.
For window lift control rear RH door down, remove window lift relay 2/119 from relay holder. Check wire for open circuit between relay holder #, switch 54/21 #6, and switch 3/86 #3, as described in Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Also check wire from 3/86 #4 and #6, and motor 6/93 #1 and #2.
For child lock, remove window lift relay 2/120 from relay holder. Check wire for open circuit between relay holder #1 switch 54/20, switch 54/21 #5, switch 3/85 and 3/86 #1, as described in Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Also check wire from 3/85 #4 and #6, motor 6/92 #1 and #2. Also check wire from 3/86 #4 and #6, motor 6/93 #1 and #2.
Do the necessary corrective action.
If no fault is found, replace control panel, (switch unit).
Additional information:
- To access the window lift relay, see Central electronic module (CEM), replacing Central Electronic Module (CEM), Replacing.
Continue - Verification
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Checking the power supply wires
- Ignition off.
Remove relay from relay holder.
Check wire between 11C/37 #2 and relay holder #3 for short circuit to ground, as described in Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Also check the wire circuit between relay #3 and motor #2 for short circuit to ground Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Additional information:
- To access the window lift relay, see Central electronic module (CEM), replacing Central Electronic Module (CEM), Replacing.
Is there a fault?
Yes - Verification
No - Checking intermittent short circuit to ground
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Checking intermittent short circuit to ground
- Ignition on.
Activate window by clicking on the VCT 2000 symbol.
Bring up the relay so that it is still connected.
Check power supply to relay by measuring voltage between #3 in the relay socket and ground.
Hint: The voltage between #3 and ground should be battery voltage.
If value deviates from this, check wire for intermittent open circuit, as described in Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.
Additional information:
- To access the window lift relay, see Central electronic module (CEM), replacing Central Electronic Module (CEM), Replacing.
- Do the necessary corrective action.
Continue - Trouble-shooting information
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Verification
Verification
Verification
Hint: After the repair it is necessary to check that the fault has been rectified.
- Ignition off.
- Connect connectors, install components etc.
- Ignition on.
Activate relay on control switch unit, window up/down.
Does it work?
Yes - VERIFIED
No - VERIFICATION FAILED
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VERIFIED - Fault Found
VERIFICATION FAILED - Trouble-shooting information
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Trouble-shooting 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 - FAULT-TRACING FAILED
No - Attempt New Test
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FAULT-TRACING FAILED - No Fault Found
Attempt New Test - Checking fuse 11C/37 (30A)
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Trouble-shooting information
Information
Fault-tracing information
If the fault is intermittent, do not verify fault-tracing if the fault does not recur.
It is possible to view the information again, or leave fault-tracing for this diagnostic trouble code (DTC).
Do you want to view the information again?
Yes - Attempt New Test
No - Fault Found
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Attempt New Test - Checking fuse 11C/37 (30A)
FAULT FOUND - DONE
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