Audi A6 Air Conditioning Repair
When Mr K brought his Audi A6 to Standish Service Station in Standish for its scheduled service, he mentioned that the air conditioning had stopped blowing cold air. Thinking it might just need a re-gas, he asked our team to check it while the car was with us.
During the service, our technicians confirmed that the refrigerant level was correct and that the system was sealed, but the cooling still wouldn’t engage. That ruled out a simple re-gas and indicated a deeper fault within the electrical side of the system.
To investigate further, we arranged a separate diagnostic appointment. When the vehicle returned, our technicians used Audi’s official wiring data and technical diagrams to assess the system’s communication network and check for faults related to the G395 pressure temperature sensor.
If your Audi A6 AC is not working, Standish Service Station can help. Read on to discover how we identified and repaired a LIN communication sensor fault through a thorough and accurate Audi AC wiring repair, restoring full cooling performance for Mr K.
Audi A6 Air Conditioning Repair: Where Our Investigation Started
After completing the service, Mr K returned to Standish Service Station in Standish so our technicians could carry out a detailed investigation into his Audi A6 air conditioning fault. During the earlier checks, we had already confirmed that the refrigerant level was correct and that the system was sealed, but the air conditioning still wouldn’t produce any cold air.
With a simple re-gas ruled out, we started our investigation. The first step was to run a system scan to see if there were any stored fault codes. Here’s what we found:
00256 – Air Conditioning Pressure/Temperature Sensor (G395): No Signal/Communication
This G395 pressure temperature sensor monitors the refrigerant’s pressure and temperature and sends that data to the control module. When the signal is lost, the compressor is automatically disabled to prevent system damage, which began to explain why the cooling function had stopped.
At this point, we couldn’t yet determine whether the fault was with the G395 sensor itself or the wiring that connects it to the control module. The next step was to dig deeper and trace the circuit to locate exactly where the communication was being lost.
The Moment the Hidden Fault Became Clear
With the initial tests complete, our next goal at Standish Service Station was to locate the point where communication had been lost between the system and the G395 pressure temperature sensor.
Using the Right Data and Tools
To progress the investigation, we referred to Audi’s official wiring diagrams and technical data. These detailed documents outlined how the G395 pressure temperature sensor receives power, shares its earth, and communicates with the control module via the LIN network — the system responsible for transmitting pressure and temperature data.
Using this information, our technician connected an oscilloscope to the sensor’s wiring to test each line:
- Power supply: Voltage present and within normal range.
- Earth: Ground connection secure and stable.
- Signal line: No visible LIN communication signal.
This showed that while the sensor was powered and earthed, no data was being transmitted to the control module. Somewhere along the line, the communication signal was being lost.
Comparing Signals Across the System
Next, we compared the readings from another sensor connected to the same LIN network. The second sensor displayed a healthy, active signal, proving that the control module and wider communication network were functioning correctly.
That narrowed the fault to the wiring between the G395 pressure temperature sensor and its next connection point in the circuit.
Tracing the Break
Following the wiring route systematically, our technician tested continuity at multiple connectors from the control module toward the front of the vehicle. The readings stayed consistent until a connector behind the passenger-side trim, suggesting the break was further along the loom.
That section of wiring runs across the nearside front wheel arch and beneath the headlamp. When the protective sleeve was carefully opened, the real fault was finally revealed — a corroded section of wiring hidden deep within the harness. Moisture had penetrated the insulation, damaging the copper strands and severing the communication line to the G395 pressure temperature sensor.
With the cause identified, the next step was to repair the wiring and confirm that full communication had been restored.
Repairing the Damage and Bringing the A/C Back to Life
With the cause of the issue located, the next task for our experts at Standish Service Station was to repair the damaged wiring and restore full communication between the G395 pressure temperature sensor and the control module. Before starting the work, we explained our findings to Mr K and outlined the steps needed to put the system right.
Accessing the Fault Area
The wiring fault was located inside the harness running over the nearside front wheel arch and beneath the headlamp. During the diagnostic stage, the protective sleeve had already been opened, allowing our technician to reach the affected section safely without disturbing the surrounding wiring.
Repairing the Wiring
Following Audi’s official repair procedures, the process was completed carefully and to a professional standard:
- The corroded wire was removed on both sides of the damaged area to expose clean, bright copper.
- A new section of matching-gauge automotive wire was installed to restore circuit continuity.
- Each connection was sealed and crimped using moisture-resistant terminals to protect against future corrosion.
- Continuity testing confirmed a stable and secure electrical connection.
Testing the Repair
Once the wiring repair was complete, we reconnected the oscilloscope to confirm that communication had been restored. This time, the LIN signal was strong, confirming that the G395 pressure temperature sensor was sending accurate data to the control module once again.
After clearing the stored fault code and restarting the air conditioning system, the compressor reactivated immediately, producing cool, steady airflow.
With the damaged wiring repaired and the communication line restored, Mr K’s Audi A6 air conditioning system was back to full working order.
Fault Resolved and Comfort Restored
For Mr K, the result was immediate. His Audi A6’s air conditioning system was once again producing cold, steady airflow — restoring both comfort and confidence on every journey. What began as a suspected re-gas turned out to be a hidden electrical wiring fault, but our skilled technicians at Standish Service Station in Standish diagnosed and repaired it with precision.
Every stage of the repair, from the initial investigation to the final signal verification, was carried out using Audi’s technical data and approved repair standards.
For our technicians, this Audi A6 air conditioning repair was another example of how structured testing and attention to detail produce lasting results. Mr K drove away knowing his system was cooling exactly as Audi intended.
Reliable Audi A6 Air Conditioning Repairs You Can Depend On
At Standish Service Station, we take pride in delivering repairs that combine precision, transparency, and trust.
Every repair we carry out follows a clear process — diagnose accurately, repair correctly, and confirm the result through thorough testing. It’s an approach that ensures our customers receive not a long-term solution.
Here’s what you can expect when you choose Standish Service Station:
- Skilled technicians trained in modern Audi systems
- Clear communication throughout
- Manufacturer-approved repair standards
- Competitive pricing compared with Audi main dealers
- 12-month parts and labour guarantee for complete reassurance
We also offer a courtesy car; ask us for more information when you book.
We proudly serve drivers across Standish, Wigan, and Bolton, with a {{average-rating}} star Google rating from {{review-count}} happy customers who trust us.
If your Audi A6 air conditioning isn’t cooling properly, call Standish Service Station on 01257 422899 — our team will find the fault, fix it the right way, and restore your comfort and confidence behind the wheel.
