B2473, B2474
Symptom: The rear windows cannot be operated.
Rear window lift motors ( B2473 - Left, B2474 - Right) Open Circuit / Shorted / Grounded
Fault symptoms
The rear windows cannot be operated.
Conditions
B2473 Open circuit on pin 11 (K20 W) or pin 12 (K20 W), left-hand rear window.
B2774 Open circuit on pin 15 (K20 W) or pin 16 (K20 W), right-hand rear window.
Diagnostic help
The window lift motors can be activated and their status read with the diagnostic tool.
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Connect the diagnostic tool.
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Turn the ignition switch to the ON position.
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Read the status of the motor or activate it.
The status of the motor can be:
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The status of the window switches can be read with the diagnostic tool. The direction of rotation of the motors can be changed by reversing the polarity.
Left-hand side:
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Window goes up when pin 11 (K20 W) is +.
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Window goes down when pin 12 (K20 W) is +.
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Right-hand side:
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Window goes up when pin 15 (K20 W) is +.
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Window goes down when pin 16 (K20 W) is +.
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Checking the wiring
Intermittent faults can occur during temporary short circuits and open circuits. Jiggle the wiring harness in several places and in various directions to detect problems in the wiring harness and connectors. Watch the multimeter, diagnostic tool and test lamp during the check.
Diagnostic procedure
1. Check the power supply to the motor
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Turn the ignition switch to the ON position.
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Connect a test lamp and activate as follows:
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between pin 1 and ground, activate DOWN.
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between pin 2 and ground, activate UP.
The test lamp should light up.
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Does the test lamp light up?
Change the motor. Continue with step 2.
Check and, if necessary, rectify the relevant lead. Continue with step 2.
2. Final check
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Clear the diagnostic trouble codes.
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Activate the window lift with the switch and raise and lower the window a few times.
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Make sure the window lift is operating correctly, noiselessly and that no trouble codes are generated.
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Has the diagnostic trouble code recurred?
Change the control module as described in
The fault has been rectified.
