Brake Booster Performance
2002-2008 Jaguar X-Type 2.5L V6
Description
The brake booster is not providing adequate assist, detected by pressure sensor or pedal effort monitoring.
Symptoms
- Hard brake pedal
- Increased stopping distance
- Brake warning light on
- Engine may stall when brakes applied firmly
Common Causes
- Leaking brake booster diaphragm
- Cracked or disconnected vacuum hose
- Check valve failure
- Brake booster control valve stuck
- Low engine vacuum on turbocharged vehicles
Diagnostic Steps
- Perform brake booster leak-down test
- Check vacuum hose and check valve
- Test engine vacuum at idle
- Apply brakes with engine off then start engine (pedal should drop)
- Check booster operating rod adjustment
Repair Notes
Replace brake booster if diaphragm is leaking. Replace vacuum hose or check valve as needed.
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
C0091 on Other Vehicles
Jaguar E-PACE
2018-2024 2.0L I4 Turbo
Jaguar F-PACE
2017-2024 2.0L I4 Turbo
Jaguar F-PACE
2017-2024 3.0L V6 Supercharged
Jaguar F-Type
2014-2024 3.0L V6 Supercharged
Jaguar F-Type R
2014-2024 5.0L V8 Supercharged
Jaguar I-PACE
2019-2024 Electric AWD
Jaguar S-Type
2000-2008 3.0L V6
Jaguar XE
2017-2024 2.0L I4 Turbo
Common Questions
What does code C0091 mean on a 2002-2008 Jaguar X-Type?
C0091 stands for "Brake Booster Performance". The brake booster is not providing adequate assist, detected by pressure sensor or pedal effort monitoring.
What are the symptoms of C0091 on a Jaguar X-Type?
Common symptoms of C0091 include: Hard brake pedal, Increased stopping distance, Brake warning light on, Engine may stall when brakes applied firmly.
What causes C0091 on a 2002-2008 Jaguar X-Type?
Common causes of C0091 include: Leaking brake booster diaphragm, Cracked or disconnected vacuum hose, Check valve failure, Brake booster control valve stuck, Low engine vacuum on turbocharged vehicles.