P3605moderate severityPowertrain
Start-Stop Climate Control Compensation Fault
on 2020 Audi R8 5.2L V10 (Gen 2, 562hp) · AWD
What this code means
The auxiliary systems that maintain cabin comfort during engine-off periods (electric A/C compressor or thermal storage) are not functioning.
Symptoms
- Start-stop deactivates quickly in hot/cold weather
- Cabin temperature drifts rapidly during stops
- A/C blows warm air at stops
- Start-stop durations very short
- Reduced fuel savings from start-stop
Common causes
- Electric A/C compressor failure
- Thermal storage evaporator issue
- Auxiliary coolant pump fault
- Electric heater element failure
- Control module communication error
Diagnostic steps
- Check auxiliary A/C compressor operation during engine stop
- Monitor cabin temperature drift rate
- Test auxiliary coolant pump
- Check electric heater circuit
- Monitor start-stop inhibit reasons
Repair notes
Replace auxiliary A/C compressor or electric heater. Repair auxiliary coolant pump if cabin heating affected.
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