2021 Audi Q7 Rear Lights Malfunction TSB 2047618/4

Audi has released Technical Service Bulletin (TSB) 2047618/4 to address a condition in 2017-2021 Audi Q7 vehicles where the rear lights may not switch correctly from the bumper to the hatchgate. This issue can lead to an important warning message appearing in the driver information system. This TSB supersedes an earlier bulletin, Group 94 number 19-03, dated February 7, 2019, with revisions for model years, production solutions, service procedures, and warranty information.

Symptoms

Owners of affected Audi Q7 models may notice that when the rear lid is closed, the lights located in the rear bumper do not transfer their function to the main lights on the rear lid. This can happen even if all rear light bulbs are fully functional and appear to be working correctly. A common indicator of this problem is the intermittent appearance of the error message "Vehicle lights: malfunction! Please contact Service" in the driver information system.

Fault Codes / DTCs

When diagnosing this condition, technicians may find the Diagnostic Trouble Code (DTC) B146C29 stored in the comfort system central control module, identified as J393 (address 0046). This DTC specifically indicates a "Rear lid -closed- sensor Implausible signal," pointing to an issue with the rear lid closed sensor.

Technical Background

The root cause of this Audi Q7 rear lights malfunction is typically incomplete actuation of the rear lid closed sensors, G525 and G526. These sensors are mounted to the base of the rear lid striker. Due to their location, debris can enter the striker housing and become lodged in the switch mechanism, preventing the sensors from fully actuating. This mechanical interference leads to the implausible signal detected by the control module.

Production Solution

Audi has implemented a production solution involving an improved rear lid closed sensor assembly. This updated sensor includes an additional enclosure designed to protect the switches from debris ingress. While this significantly enhances the debris resistance of the switches, it cannot entirely eliminate the possibility of debris accumulation.

Repair Procedure Summary

To address the Audi Q7 rear lights malfunction, technicians will perform the following steps:

1. The striker cover on the loading sill cover will be pressed down to access the sensor area.
2. If debris is found obstructing the G525/G526 switch activation/deactivation, the technician will activate the switch paddles manually and remove the debris. Compressed air is an effective tool for this step.
3. After clearing debris, the measuring values for the G525 and G526 switches will be checked.
4. If the malfunction persists after cleaning and checking values, the rear lid closed sensor will be replaced. Only the improved sensor, which includes the protective enclosure, should be used for replacement.

Required Parts and Tools

The primary part required for this repair is the Rear Lid Closed Sensor. Specific part numbers should be obtained from ETKA (Electronic Parts Catalog). Additionally, any necessary fasteners, bolts, nuts, and screws should be referenced in the Repair Manual and sourced via ETKA/ELSA.

Warranty Information

This repair is covered under Audi's warranty for up to 48 months or 50,000 miles, whichever comes first. For Certified Pre-Owned (CPO) vehicles, coverage is under G10, subject to owner verification. If the vehicle is outside of warranty, this Technical Service Bulletin 2047618/4 serves as informational guidance only.

Service Number: 9661 Damage Code: 0015

Labor Operations:

• Luggage compartment rear trim remove and reinstall: 7006 1900
• Lock carrier cover remove and reinstall: 7039 1950
• Rear Lid Closed Sensor G525/G526 replace: 9661 1950
• Rear Lid Closed Sensor G525/G526 - clear with compressed air: 9661 9999 (30 Time Units)

Diagnostic Time: GFF (0150 0000) for 20 Time Units.

All warranty claims must adhere to the Audi Warranty Policies and Procedures Manual and are subject to review by Audi Warranty.

Source: NHTSA ID 10174050