Known JLR Fault
Land Rover Discovery 3 ACE (Active Cornering Enhancement) Failure
Affects
Overview
The Active Cornering Enhancement (ACE) system on the Land Rover Discovery 3 uses a hydraulic anti-roll bar system to reduce body roll in corners. It's a complex hydraulic system with a pump, valve block, and hydraulic actuators at each axle. When the ACE system fails — typically through fluid loss, pump failure, or valve block issues — the vehicle will feel extremely unstable in corners.
Symptoms
- ▶ACE warning light on dashboard — often amber or red
- ▶'ACE fault — reduced cornering stability' message
- ▶Excessive body roll in corners — vehicle feels unstable
- ▶Clunking from front or rear suspension in corners
- ▶Hydraulic fluid leak from ACE pump or pipework
- ▶ACE pump running excessively or making unusual noise
What Causes It?
- ✕ACE hydraulic fluid loss from leaking pipework or actuator seals
- ✕ACE pump failure from running with low fluid level
- ✕ACE valve block solenoid failure
- ✕ACE sensor failure giving incorrect roll data to the control module
The Solution
JLRMAN diagnoses ACE faults using SDD to read ACE fault codes and live sensor data. We pressure-test the ACE hydraulic circuit to identify leaks and inspect the pump and valve block. Fluid leaks are repaired at source and the system flushed and refilled with the correct fluid. Pump or valve block replacement is carried out where required, followed by full system calibration.
How to Prevent It
Check ACE fluid level at every service and inspect hydraulic pipework for signs of seeping — fluid loss is the primary trigger for pump failure on the Discovery 3 ACE system.
Other Common JLR Faults
Jaguar XF Electrical Problems
Jaguar XF X250 (2008–2015)
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Range Rover Air Suspension Failure
Range Rover L322 (2002–2012)
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Land Rover Discovery 3 & 4 EGR Cooler Failure
Land Rover Discovery 3 TDV6 (2004–2009)
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Range Rover Sport Timing Chain Failure
Range Rover Sport L320 TDV6 (2005–2013)
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Typical Repair Cost
£400–£1,500
Cost varies by model, severity, and parts required. Contact JLRMAN for a no-obligation quote specific to your vehicle.
Experiencing This Fault?
Don't wait for it to get worse. JLRMAN diagnoses JLR faults correctly — and fixes them properly.
Related Service
Diagnostics
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Experiencing a JLR Fault?
Don't wait for it to get worse. JLRMAN diagnoses correctly the first time.