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2005-2011 AUDI A6
4.2L V8•AWD•AUTOMATIC•gas•BAT
5 active safety recalls on this vehicle — view recalls
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Repairs0Labor504Torque2218Fluid10DTC1868Battery1Maintenance0Recalls5
P0991moderate severityPowertrain

Transmission Fluid Pressure Sensor/Switch F Circuit Intermittent/Erratic

on 2005-2011 Audi A6 4.2L V8 · AWD

What this code means

The signal from transmission fluid pressure sensor F is dropping out or jumping around instead of staying steady. This usually points to a loose connection or a failing sensor.

Symptoms

  • Erratic or harsh shifting
  • Transmission warning light on
  • Intermittent limp mode

Common causes

  • Loose or corroded sensor connector
  • Damaged sensor wiring
  • Faulty pressure sensor F
  • Low or contaminated transmission fluid

Diagnostic steps

  1. Scan for stored and pending codes
  2. Inspect sensor connector and wiring while wiggling
  3. Monitor pressure sensor data during a test drive
  4. Replace sensor if signal drops out under known-good wiring
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