P0849moderate severityPowertrain
Transmission Fluid Pressure Sensor/Switch B Intermittent
on 2017 Audi S5 3.0L Supercharged V6 · AWD
What this code means
The PCM detects an intermittent signal fault from transmission fluid pressure sensor/switch B. The issue may appear and disappear during operation.
Symptoms
- Intermittent harsh shifts
- Warning light flickers
- Momentary limp mode
Common causes
- Loose or corroded connector
- Chafed or intermittent wiring
- Faulty pressure sensor B
- Faulty PCM/TCM
Diagnostic steps
- Scan and record freeze frame data
- Wiggle test wiring and connector while monitoring
- Inspect for corrosion and loose pins
- Verify sensor signal stability under load
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