C0090
Brake Booster Pressure Sensor Circuit
2000-2003 Audi S6 4.2L V8
Moderate SeverityChassisGeneric (SAE)
Description
Malfunction in the brake booster vacuum or pressure sensor circuit.
Symptoms
- Brake warning light on
- Hard brake pedal
- Increased stopping distance
- Check Engine Light may also be on
Common Causes
- Faulty brake booster pressure sensor
- Vacuum hose leak
- Wiring damage
- Brake booster vacuum pump failure on diesel/turbo vehicles
Diagnostic Steps
- Test brake booster vacuum with gauge
- Check vacuum hose to booster
- Test pressure sensor signal
- Inspect wiring and connector
- Check engine vacuum source
Repair Notes
Repair vacuum leak or replace pressure sensor. On diesel vehicles, check vacuum pump.
Related Codes
Other Chassis Codes
- C0021LF Wheel Speed Sensor Range/Performance
- C0022RF Wheel Speed Sensor Range/Performance
- C0023LR Wheel Speed Sensor Range/Performance
- C0024RR Wheel Speed Sensor Range/Performance
- C0025LF Wheel Speed Sensor Circuit Intermittent
- C0026RF Wheel Speed Sensor Circuit Intermittent
- C0027LR Wheel Speed Sensor Circuit Intermittent
- C0028RR Wheel Speed Sensor Circuit Intermittent
- C0035Left Front Wheel Speed Sensor Circuit
- C0036Left Front Wheel Speed Signal Erratic
C0090 on Other Vehicles
Common Questions
What does code C0090 mean on a 2000-2003 Audi S6?
C0090 stands for "Brake Booster Pressure Sensor Circuit". Malfunction in the brake booster vacuum or pressure sensor circuit.
What are the symptoms of C0090 on a Audi S6?
Common symptoms of C0090 include: Brake warning light on, Hard brake pedal, Increased stopping distance, Check Engine Light may also be on.
What causes C0090 on a 2000-2003 Audi S6?
Common causes of C0090 include: Faulty brake booster pressure sensor, Vacuum hose leak, Wiring damage, Brake booster vacuum pump failure on diesel/turbo vehicles.