2017-2026 Audi Q7/Q8 Radiator Fan & Wiper Faults TSB

Audi has released Technical Service Bulletin (TSB) 2073305/2 to address concerns regarding constantly running radiator fans and non-functional windshield wipers in certain 2017-2026 Audi Q7, SQ7, Q8, SQ8, and RS Q8 models. This TSB provides diagnostic guidance and a repair procedure for technicians to resolve these electrical system malfunctions.

The underlying cause of these problems is typically wire damage or chafing within the vehicle's plenum chamber, which can lead to communication issues and circuit faults. Owners experiencing these symptoms, such as a persistent Audi Q8 radiator fan operation, should have their vehicle inspected by an authorized Audi service center.

Symptoms

Owners of affected Audi vehicles may observe one or both of the following primary symptoms:

• "The radiator fans run constantly."
• "The windshield wipers do not work."

These symptoms point to electrical system malfunctions that can affect critical vehicle functions.

Fault Codes / DTCs

Technicians diagnosing these issues may find one or more of the following Diagnostic Trouble Codes (DTCs) stored as static or intermittent faults in various control units:

Diagnostic Address	Diagnostic Trouble Code	Fault Symptom	Storage State
0046 - Convenience system central module	U10F300	Sirens / alarm horn for anti-theft warning system no communication	static
0009 - Electronic central electric	U10A300	Wiper motor control module no communication	static
0001 - Engine electronics	P048000	Cooling Fan 1 Control Circuit	static
0001 - Engine electronics	U063200	Lost Communication With Fan 1	static
0001 - Engine electronics	P10EF00	Function limitation due to failure of cooling fan	static
0001 - Engine electronics	P048100	Cooling Fan 2 Control Circuit	static
0001 - Engine electronics	U063300	Lost Communication With Fan 2	static

Diagnosis / Trigger Conditions

The root cause of the issues, including the constantly running Audi Q8 radiator fan and non-functional wipers, is often identified as wire damage or chafing. This damage typically occurs on circuits routed through the plenum chamber. In some cases, the damage may not be immediately visible and might only become apparent once the harness wrapping is removed. Technicians will check for high resistance, open circuits, and short circuits using a Digital Volt-Ohm Meter (DVOM).

Repair Procedure Summary

The repair for TSB 2073305/2 involves addressing the damaged wiring in the plenum chamber. The general procedure includes:

1. Circuit Inspection: Technicians will check the affected circuits for high resistance, open circuits, and short circuits using a DVOM.
2. Locating Damage: Moving and flexing the wiring harness throughout the plenum chamber will help pinpoint the exact area of concern. Figure 1 in the TSB illustrates that external damage to the wiring harness might not be visible.
3. Wire Repair: Damaged wires are to be repaired using a specialized wiring harness repair set, specifically VAS1978. If wire strands are not clean and shining, the wire must be cut back and lengthened as needed.
4. Harness Wrapping: After repairs, the wiring harness is re-wrapped using fabric adhesive tape, part number N 10592002. Figure 2 in the TSB shows how damaged wires become visible once the original wrapping is removed.

Required Tools or Parts

To perform the repair outlined in TSB 2073305/2, technicians will require specific tools and parts:

• Wire harness repair set: VAS 1978 B
• Cloth adhesive tape: N 10592002
• VAS tester: With the current version of ODIS (Windows 10), specifically VAS 6160/VAS 6150
• Fasteners, Bolts, Nuts, and Screws: As needed per the repair manual (refer to ETKA).

Important Warnings

Owners should be aware that if their vehicle is outside of any warranty, this Technical Service Bulletin is informational only. In such cases, repair costs may not be covered by Audi.

Warranty Information

For vehicles under warranty, claims submitted for payment must adhere to the Audi Warranty Policies and Procedures Manual. The Service Number for this repair is 9713, and the Damage Code is 0015. Labor operations include removing and installing the cowl panel trim (6644 1900), checking the wiring harness (9709 0199), and repairing the wiring harness (9709 41xx), depending on the number of defective wires.

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Source: NHTSA ID: 11023760