2025 Audi Q5 A/C Not Cooling TSB 2079080/1

Symptoms and Customer Complaint

Owners of 2025 Audi Q5 vehicles may experience a noticeable lack of cooling from their air conditioning system. The primary symptom reported is that the "97 Air conditioner does not cool the interior." This leads to an uncomfortable cabin environment, especially during warmer weather.

The customer complaint is specifically described as "climate control -> heating, cooling -> climate control unit cooling output functionality -> no function." This indicates a complete failure of the climate control unit to provide cooling output, directly impacting the vehicle's comfort systems.

Diagnostic Trouble Codes (DTCs)

When diagnosing the 2025 Audi Q5 A/C not cooling issue, technicians will typically find specific diagnostic trouble codes (DTCs) stored in the vehicle's control units. These codes are crucial for pinpointing the electrical fault within the air conditioning system. The following codes are commonly logged as passive or intermittent entries:

Code	Description	Diagnostic Address	Storage State
B148812	A/C clutch Short circuit to B+	0008 - HVAC electronics	Intermittent
B148812	A/C clutch Short circuit to B+	00C5 - Thermal management	Intermittent
B148815	A/C clutch open circuit/short circuit to B+	0008 - HVAC electronics	Intermittent
B148815	A/C clutch open circuit/short circuit to B+	00C5 - Thermal management	Intermittent

These DTCs indicate electrical faults related to the A/C clutch circuit, specifically a short circuit to B+ (battery positive) or an open circuit/short circuit to B+. These codes are found in the HVAC electronics control unit (diagnostic address 0008) and/or the thermal management control unit (diagnostic address 00C5).

Technical Background and Production Solution

Technical Service Bulletin 2079080/1, released on August 27, 2025, identifies a manufacturing issue as the root cause of the 2025 Audi Q5 A/C not cooling problem. For vehicles produced within a specific period, the wiring connected to the N280 (brown connector for N25), which controls the air conditioning system magnetic clutch, was found to be too short. This insufficient wire length can lead to excessive strain on the wiring, resulting in the short or open circuit conditions that trigger DTCs B148812 and B148815.

Audi has implemented a production solution to address this concern. Vehicles manufactured after July 17, 2025, now incorporate longer wiring for this specific component. This change prevents the recurrence of this particular wiring fault directly from the factory, ensuring improved durability and reliability of the A/C system in newer production models.

Diagnosis and Trigger Conditions

To accurately diagnose the 2025 Audi Q5 A/C not cooling issue, technicians should begin by verifying the customer's complaint regarding the lack of interior cooling. This can involve checking the A/C system's functionality and temperature output. Following this, a comprehensive scan of the vehicle's control units is essential to check for stored event memory entries.

The presence of DTCs B148812 or B148815 in either the thermal management control unit (diagnostic address 00C5) or the control unit for air conditioner and heater electronics (diagnostic address 0008) confirms the condition described in TSB 2079080/1. These fault codes are typically logged as passive or intermittent, meaning the fault may not be continuously active but has occurred at some point, indicating an underlying wiring issue.

Detailed Repair Procedure

Addressing the 2025 Audi Q5 A/C not cooling issue involves a precise repair procedure to correct the wiring fault. This procedure, outlined in Technical Service Bulletin 2079080/1, focuses on repairing the affected wiring harness leading to the N280 component (brown connector for N25):

1. Reproduce Complaint: The technician must first attempt to reproduce the customer's complaint to confirm the air conditioning system is not cooling as expected.
2. Locate Discrepancy: Identify any discrepancy or damage in the wire leading to the brown connector (N25) on the N280 component. This is the area where the original wiring was found to be too short.
3. Perform Wire Repair: Repair the damaged wire using the specialized wiring harness repair set, specifically the VAS 1978 B/C tool. This tool ensures a precise and durable repair of the electrical connection.
4. Crimp Connector Placement: Carefully place the crimp connector into the correct position. The TSB illustrates this position with a red arrow in Figure 1, guiding the technician to ensure proper electrical connection and mechanical integrity.
5. Ensure Correct Wire Length: It is critical to ensure that the length of the wire between the cable tie and the brown connector (indicated by a yellow arrow in Figure 1) measures precisely 60mm. This specific length is vital to prevent the wire from being too short again, which was the original cause of the problem. Figure 2 in the TSB shows the connector in its correctly repaired state, emphasizing the required wire length.
6. Insulate with Fabric Tape: Wrap the repaired wire with fabric adhesive tape, part number N10649702. The tape should extend almost as far as the connector, overlapping slightly to provide complete insulation and protection against environmental factors and abrasion.
7. Secure Wiring: To further secure the repair and prevent future strain, wrap the fabric adhesive tape at least 2.5 times underneath the area where the omega clip's cable tie is located. This ensures that the wire is securely fastened within the cable tie, preventing any movement or stress that could lead to future damage or recurrence of the fault.

Parts and Special Tools Required

To perform the repair described in TSB 2079080/1 for the 2025 Audi Q5 A/C not cooling problem, specific parts and a special tool are required to ensure a correct and lasting fix:

• Wiring harness repair set VAS 1978 B/C: This is a specialized tool kit essential for the precise and professional repair of the wiring harness. It is not a consumable part but a required piece of equipment.
• Fabric tape (Part Number N10649702): A quantity of 0.3 units is specified for insulation and protection of the repaired wire.
• Omega clip (Part Number N10760401): One unit of this clip is required for securely fastening the wiring.
• Crimp connector (Part Number 000979940): One unit is needed for making the electrical connection in the repaired section of the harness.
• Wire (Part Number 000979025EC): One unit of the correct gauge and type of wire is necessary for the repair.

Warranty Claim Details

Audi provides specific guidelines for warranty claims related to Technical Service Bulletin 2079080/1. For vehicles still under the manufacturer's warranty, this repair should be covered. Important: If the vehicle is outside of its warranty period, this Technical Service Bulletin is for informational purposes only, and the repair costs may not be covered by Audi.

• Service Number: 9712
• Damage Code: 0029
• Labor Operations:
  • Remove and install noise insulation: 1082 1900 (Refer to SRT with associated operations)
  • Repair wiring harness: 9709 4151 (Refer to SRT with associated operations)
  • Modify wiring harness: 9712 4199 (5 TU - Technical Units)
  • GFF / Guided Functions: 0150 0060 (Labor according to the diagnostic log)
• Claim Comment: As per TSB 2079080/1

All warranty claims submitted for payment must be in strict accordance with the Audi Warranty Policies and Procedures Manual. Claims are subject to review or audit by Audi Warranty to ensure compliance and proper documentation.

Important Notes for Technicians

When submitting warranty claims for this repair, it is crucial to attach clear photographic or video documentation that accurately shows the complaint to DOC-IT. To ensure a valid reference to the vehicle and the issue, the images or videos must:

• Include the Vehicle Identification Number (VIN) and the date.
• Not be edited or altered in any way.
• Be in focus and taken with sufficient light to clearly show the problem.
• A high resolution is not necessary, but clarity is paramount.

If appropriate, technicians should clearly mark the location of the problem so that parts analysis has a clear reference to the complaint. It is also important to ensure that the photo documentation does not show any people and/or faces, license plates, or customer data to maintain privacy and confidentiality.

Source: NHTSA ID 11022703