2010 JAGUAR XFR brake light

Symptom Possible Cause Action Electrical circuit
For parking brake control and circuit tests.
REFER to: Parking Brake (206-05, Diagnosis and Testing). Slow or incomplete brake
pedal return
Brake pedal binding
Brake booster/master cylinder GO to Pinpoint Test K. Pinpoint Tests

PINPOINT TEST A : BRAKES NOISY TEST
CONDITIONS DETAILS/RESULTS/ACTIONS A1: INSPECT BRAKE PADS 1 Inspect the condition of the front and rear brake pads. Check for damage to any anti-squeal shims. Are the brake pads OK? Yes
GO to A2. No
Clean/install new front and rear brake pads as required. REFER to:
Brake Pads - Vehicles With: Standard Brakes (206-03A Front Disc Brake - V6 3.0L Petrol, Removal and Installation),
Brake Pads - Vehicles With: High Performance Brakes (206-03A Front Disc Brake - V6 3.0L Petrol, Removal and Installation),
Brake Pads (206-04A Rear Disc Brake - V6 3.0L Petrol, Removal and Installation), Brake Pads - Vehicles With: High Performance Brakes (206-04, Removal and Installation).
Re-test vehicle for brake noise. A2: INSPECT BRAKE DISCS 1 Inspect the brake discs for excessive corrosion, wear or disc thickness variation. Does excessive corrosion, wear or disc thickness variation exist? Yes
Install new front and rear brake discs and brake pads as required. REFER to:
Brake Pads - Vehicles With: Standard Brakes (206-03A Front Disc Brake - V6 3.0L Petrol, Removal and Installation),
Brake Pads - Vehicles With: High Performance Brakes (206-03A Front Disc Brake - V6 3.0L Petrol, Removal and Installation),
Brake Pads (206-04A Rear Disc Brake - V6 3.0L Petrol, Removal and Installation), Brake Pads - Vehicles With: High Performance Brakes (206-04, Removal and Installation),
Brake Disc - Vehicles With: Standard Brakes (206-03A Front Disc Brake - V6 3.0L Petrol, Removal and Installation),
Brake Disc - Vehicles With: High Performance Brakes (206-03A Front Disc Brake - V6 3.0L Petrol, Removal and Installation),
Brake Disc (206-04A Rear Disc Brake - V6 3.0L Petrol, Removal and Installation), Brake Disc - Vehicles With: High Performance Brakes (206-04, Removal and Installation).
Re-test vehicle for brake noise.
No
No action required, vehicle is OK.
PINPOINT TEST B : VIBRATION WHEN BRAKES ARE APPLIED TEST
CONDITIONS DETAILS/RESULTS/ACTIONS B1: ROAD TEST VEHICLE 1 Road test the vehicle between 40-80 km/h (25-50 mph) without applying brakes. Is the vibration present?
Yes
For noise vibration and harshness tests.
REFER to: Noise, Vibration and Harshness (NVH) (100-04 Noise, Vibration and Harshness, Diagnosis and Testing).
No
GO to B2. B2: CHECK FOR BRAKE VIBRATION 1 Road test the vehicle between 40-80 km/h (25-50 mph) with light and medium application on the brake pedal. Is a vibration present?
Yes
Check the brake caliper mounting bolts and wheel hub nuts and tighten to specification as required. Check
the balance of all road wheels and tires and repair as required. Check the brake discs for excessive wear,
runout, thickness variation or cracks. Install new brake discs and brake pads as required. GO to B3. No
No action required, vehicle is OK. B3: IS VIBRATION STILL PRESENT UNDER BRAKE APPLICATION? 1 Road test the vehicle between 40-80 km/h (25-50 mph) with light and medium application on the brake pedal.

TEST
CONDITIONS DETAILS/RESULTS/ACTIONS D1: CHECK FOR SPONGY PEDAL (ENGINE OFF) 1 Check for a firm brake pedal. Is the brake pedal effort and brake pedal travel normal? Yes
No action is required, vehicle is OK.
No
GO to D2. D2: CHECK BRAKE PEDAL RESERVE (ENGINE OFF) 1 Pump the brake pedal 10 times and hold on the final application. Does the brake pedal feel firm on final application? Yes
GO to D3. No
Bleed the brake system.
REFER to: Brake System Bleeding (206-00 Brake System - General Information, General Procedures). D3: CHECK BRAKE PEDAL RESERVE (ENGINE ON) 1 With engine running at idle speed. 2 Apply the brake pedal lightly three or four times. 3 Wait 15 seconds for the vacuum to recover. 4 Push down on the brake pedal until it stops moving downward or an increased resistance to the brake pedal travel occurs. 5 Hold the brake pedal in the applied position while increasing the engine speed to 2000 revs/min. 6 Release the accelerator pedal. Does the brake pedal move downward as the engine speed returns to idle? Yes
GO to D4. No
Check the vacuum to brake booster. D4: CHECK BRAKE FLUID LEVEL 1 Check the brake master cylinder reservoir fluid level. Is the fluid level OK? Yes
Bleed the brake system.
REFER to: Brake System Bleeding (206-00 Brake System - General Information, General Procedures). Re-test the system for normal operation.
No
Check for leaking brake system and rectify as required. Add fluid and bleed the brake system.
REFER to: Brake System Bleeding (206-00 Brake System - General Information, General Procedures). Re-test the system for normal operation.
PINPOINT TEST E : THE PEDAL GOES DOWN FAST TEST
CONDITIONS DETAILS/RESULTS/ACTIONS E1: ROAD TEST VEHICLE 1 Road test the vehicle and apply the brake pedal. Is the brake pedal effort and brake pedal travel normal? Yes
No action required, vehicle is OK.
No
GO to E2. E2: CHECK BRAKE PEDAL TRAVEL-PRESSURIZE SYSTEM 1 Pump the brake pedal rapidly (five times). Does the brake pedal travel build up and then hold? Yes
Bleed the brake system.
REFER to: Brake System Bleeding (206-00 Brake System - General Information, General Procedures). Re-test the system for normal operation.
No
GO to E3. E3: CHECK FOR BRAKE SYSTEM LEAKS Is the alignment within specification?
Yes
No action is required, vehicle is OK.
No
Adjust the alignment as required. REFER to:
Front Subframe - 2.7L Diesel (502-00, Removal and Installation),
Front Subframe - V6 3.0L Petrol (502-00 Uni-Body, Subframe and Mounting System, Removal and Installation),
Front Subframe - 4.2L (502-00, Removal and Installation).

Inspect the brake booster, rubber grommet, and all vacuum plumbing for cracks, holes, damaged connections, or missing clamps. 4 Pump the brake pedal several times to exhaust the vacuum. Push down on the brake pedal and hold. Does the brake pedal move down when the engine is started?
Yes
Vacuum system is OK.
No
GO to G4. G4: CHECK POWER BRAKE BOOSTER VALVE 1 Check the brake booster valve. For additional information, refer to Brake Booster component test in this section. Is the power brake booster valve OK?
Yes
Check the brake booster. For additional information, refer to Brake Booster component test in this
section. Install a new brake booster as required. REFER to:
Brake Booster (206-07 Power Brake Actuation, Removal and Installation), Brake Booster - RHD (206-07, Removal and Installation).
Re-test the system for normal operation.
No
Install a new brake booster valve. Re-test the system for normal operation.
PINPOINT TEST H : BRAKE LOCKUP DURING LIGHT BRAKE PEDAL FORCE TEST
CONDITIONS DETAILS/RESULTS/ACTIONS H1: TEST BRAKE LOCKUP 1 Road test the vehicle and apply the brake pedal lightly. Do the brakes lockup?
Yes
GO to H2. No
No action required, vehicle is OK. H2: INSPECT BRAKE PADS 1 Inspect brake pads for contamination, correct installation, damage and type. Has a concern been identified?
Yes
Correctly install or install new brake pads as required. REFER to:
Brake Pads - Vehicles With: Standard Brakes (206-03A Front Disc Brake - V6 3.0L Petrol, Removal and Installation),
Brake Pads - Vehicles With: High Performance Brakes (206-03A Front Disc Brake - V6 3.0L Petrol, Removal and Installation),
Brake Pads (206-04A Rear Disc Brake - V6 3.0L Petrol, Removal and Installation), Brake Pads - Vehicles With: High Performance Brakes (206-04, Removal and Installation).
Re-test the system for normal operation.
No
GO to H3. H3: INSPECT BRAKE CALIPERS 1 Inspect brake calipers for binding, leaking or sticking. Has a concern been identified?
Yes
Correctly install or install new brake calipers as required. REFER to:
Brake Caliper - Vehicles With: Standard Brakes (206-03A Front Disc Brake - V6 3.0L Petrol, Removal and Installation),
Brake Caliper - Vehicles With: High Performance Brakes (206-03A Front Disc Brake - V6 3.0L Petrol, Removal and Installation),
Brake Caliper (206-04A Rear Disc Brake - V6 3.0L Petrol, Removal and Installation), Brake Caliper - Vehicles With: High Performance Brakes (206-04, Removal and Installation).
Re-test the system for normal operation.
No
No action required, vehicle is OK.
PINPOINT TEST I : BRAKES DRAG TEST
CONDITIONS DETAILS/RESULTS/ACTIONS I1: ROAD TEST VEHICLE 1 Road test the vehicle and apply the brakes. Are the brakes functioning correctly? Yes
No action required, vehicle is OK.
No
GO to I2. I2: CHECK BRAKE CALIPERS 1 Check the front and rear calipers pistons and pins for binding, leaking or sticking.

Yes
Inspect the brake calipers and parking brake cables. Install new components as required. Re-test the
system for normal operation.
No
GO to I3. I3: CHECK BRAKE BOOSTER 1 Check the brake booster connecting rod alignment and travel. Is the connecting rod OK? Yes
Vehicle is OK.
No
Install a new brake booster as required. REFER to:
Brake Booster (206-07 Power Brake Actuation, Removal and Installation), Brake Booster - RHD (206-07, Removal and Installation).
Re-test the system for normal operation.
PINPOINT TEST J : EXCESSIVE/ERRATIC BRAKE PEDAL TRAVEL TEST
CONDITIONS DETAILS/RESULTS/ACTIONS J1: TEST ON ROUGH ROAD 1 Road test the vehicle on rough road conditions. 2 Apply the brakes slowly. Is the brake pedal effort and brake pedal travel normal?
Yes
No action required, vehicle is OK.
No
GO to J2. J2: CHECK BRAKE FLUID LEVEL 1 Check the brake master cylinder reservoir fluid level. Is the fluid level OK?
Yes
GO to J3. No
Check brake master cylinder reservoir sealing points. For additional information, refer to Brake master
cylinder component test in this section. Add brake fluid and bleed the brake system.
REFER to: Brake System Bleeding (206-00 Brake System - General Information, General Procedures). Re-test the system for normal operation. J3: CHECK BRAKE PEDAL RESERVE 1 Run engine at idle speed. 2 Apply the brake pedal lightly three or four times. 3 Wait 15 seconds for the vacuum to replenish. 4 Push down on the brake pedal until it stops moving downward or an increased resistance to the brake pedal travel occurs. 5 Hold the brake pedal in the applied position while increasing the engine speed to 2000 revs/min. 6 Release the accelerator pedal. Does the brake pedal move downward as the engine speed returns to idle?
Yes
GO to J4. No
Check the vacuum to the brake booster. J4: CHECK THE FRONT WHEEL BEARING ASSEMBLY 1 Check the front wheel bearing assembly. Are the front wheel bearings loose/damaged?
Yes
Tighten to specification or install a new front wheel bearing as required.
REFER to: Front Wheel Bearing and Wheel Hub - V6 3.0L Petrol (204-01 Front Suspension, Removal and Installation).
Re-test the system for normal operation.
No
Check the front brake discs for thickness variances.
PINPOINT TEST K : SLOW OR INCOMPLETE BRAKE PEDAL RETURN TEST
CONDITIONS DETAILS/RESULTS/ACTIONS K1: CHECK FOR BRAKE PEDAL RETURN 1 Run the engine at idle while making several brake applications. 2 Pull the brake pedal rearward with approximately 44.5 N (10lb) force. 3 Release the brake pedal and measure the distance to the toe board. 4 Make a hard brake application. 5 Release the brake pedal and measure the brake pedal to toe board distance. The brake pedal should return to its original position.

Does the brake pedal return to its original position? Yes
No action required, vehicle is OK.
No
GO to K2. K2: CHECK FOR BRAKE PEDAL BINDING 1 Disconnect the brake booster from the brake pedal. Check the brake pedal to ensure free operation. Is the brake pedal operating freely? Yes
Install a new brake booster as required. REFER to:
Brake Booster (206-07 Power Brake Actuation, Removal and Installation), Brake Booster - RHD (206-07, Removal and Installation).
Re-test the system for normal operation.
No
Repair or install new brake pedal. Re-test the system for normal operation. Component Tests

Brake Booster

1. Check all hoses and connections. All unused vacuum connectors should be capped. Hoses and their connections should
be correctly secured and in good condition with no holes and no collapsed areas. Inspect the valve on the brake booster
for damage.
2. Check the hydraulic brake system for leaks or low fluid.

3. With the automatic transmission in PARK, stop the engine and apply the parking brake. Pump the brake pedal several
times to exhaust all vacuum in the system. With the engine switched off and all vacuum in the system exhausted,
apply the brake pedal and hold it down. Start the engine. If the vacuum system is operating, the brake pedal will tend
to move downward under constant foot pressure. If no motion is felt, the vacuum booster system is not functioning.

4. Remove the vacuum hose from the brake booster. Manifold vacuum should be available at the brake booster end of the
hose with the engine at idle speed and the automatic transmission in PARK. Make sure that all unused vacuum outlets
are correctly capped, hose connectors are correctly secured and vacuum hoses are in good condition. When it is
established that manifold vacuum is available to the brake booster, connect the vacuum hose to the brake booster and
repeat Step 3. If no downward movement of the brake pedal is felt, install a new brake booster.

5. Operate the engine for a minimum of 10 seconds at a fast idle. Stop the engine and allow the vehicle to stand for 10
minutes. Then, apply the brake pedal with approximately 89 N (20lb) of force. The pedal feel (brake application) should
be the same as that noted with the engine running. If the brake pedal feels hard (no power assist), install a new valve
and then repeat the test. If the brake pedal still feels hard, install a new brake booster. If the brake pedal movement
feels spongy, bleed the brake system.
REFER to: Brake System Bleeding (206-00 Brake System - General Information, General Procedures). Brake Master Cylinder

Usually, the first and strongest indicator of anything wrong in the brake system is a feeling through the brake pedal. In
diagnosing the condition of the brake master cylinder, check pedal feel as evidence of a brake concern. Check for brake warning
lamp illumination and the brake fluid level in the brake master cylinder reservoir.
Normal Conditions
The following conditions are considered normal and are not indications that the brake master cylinder is in need of repair.

Modern brake systems are designed to produce a pedal effort that is not as hard as in the past. Complaints of light
pedal efforts should be compared to the pedal efforts of another vehicle of the same model and year.
The fluid level will fall with brake pad wear.

Abnormal Conditions

Changes in the brake pedal feel or brake pedal travel are indicators that something could be wrong in the brake system. The
diagnostic procedure and techniques use brake pedal feel, warning indicator illumination and low brake fluid level as indicators
to diagnosing brake system concerns. The following conditions are considered abnormal and indicate that the brake master
cylinder is in need of repair:

NOTE: Prior to carrying out any diagnosis, make sure the brake system warning indicator is functional.
Brake pedal goes down fast. This could be caused by an external or internal leak.
Brake pedal goes down slowly. This could be caused by an internal or external leak.
Brake pedal is low or feels spongy. This condition may be caused by no fluid in the brake master cylinder, reservoir cap
vent holes clogged or air in the hydraulic system.
Brake pedal effort is excessive. This may be caused by a bind or obstruction in the pedal/linkage, a faulty non-return
valve, booster or insufficient booster vacuum.
Rear brakes lock up during light pedal force. This may be caused by damaged brake pads, a partially applied parking
brake, a damaged ABS sensor or bearing failure.
Brake pedal effort erratic. This condition could be caused by the brake booster or incorrectly installed brake pads.
Brake warning indicator is on. This may be caused by low fluid level or float assembly damaged. www.JagDocs.com

BRAKE CALIPERS System Operation

When hydraulic pressure is supplied to the caliper, the pistons extend to force the inner pad against the brake disc. The caliper
reacts and slides along two guide pins to bring the outer pad into contact with the brake disc.

BRAKE PAD WEAR SENSORS

When a brake pad incorporating a brake pad wear sensor is approximately 75% worn, the sensor wire within the pad material
is worn through and the brake pad wear sensor goes open circuit. When the instrument cluster detects the open circuit, it
illuminates the amber LED (light emitting diode) in the brake warning indicator, displays an appropriate warning in the
message center and sounds a warning chime.
Refer to: Instrument Cluster (413-01 Instrument Cluster, Description and Operation).

NOTE: A new pad wear sensor lead must be fitted whenever the brake pads are changed, irrespective of the brake pad
warning sensor being triggered.



BRAKE CALIPERS Component Description

Each caliper is mounted within a fixed carrier that is secured to the front wheel knuckle with two bolts. The inboard brake pad
of the LH (left-hand) brake incorporates a wear sensor.

Each outboard brake pad is installed with a pressed steel anti-rattle spring. On SC (supercharger) vehicles, a badge with the
'R' symbol is formed on the anti-rattle spring.

BRAKE PAD WEAR SENSORS

The brake pad wear sensor is wired in series with a wear sensor on the RH (right-hand) rear brake and the instrument cluster.
If the thickness of one of the brake pads connected to a wear sensor decreases to a predetermined limit, the instrument
cluster illuminates the brake warning indicator.

BRAKE CALIPERS System Operation

When hydraulic pressure is supplied to the caliper, the pistons extend to force the inner pad against the brake disc. The caliper
reacts and slides along two guide pins to bring the outer pad into contact with the brake disc.

BRAKE PAD WEAR SENSORS

When a brake pad incorporating a brake pad wear sensor is approximately 75% worn, the sensor wire within the pad material
is worn through and the brake pad wear sensor goes open circuit. When the instrument cluster detects the open circuit, it
illuminates the amber LED (light emitting diode) in the brake warning indicator, displays an appropriate warning in the
message center and sounds a warning chime.
Refer to: Instrument Cluster (413-01 Instrument Cluster, Description and Operation).

NOTE: A new pad wear sensor lead must be fitted whenever the brake pads are changed, irrespective of the brake pad
warning sensor being triggered.



BRAKE CALIPERS Component Description

Each caliper is mounted within a fixed carrier that is secured to the rear wheel knuckle with two bolts. Each outboard brake pad
is installed with a wire anti-rattle spring.

The brake calipers on SC (supercharger) vehicles are painted and also include a logo badge, secured with two screws, which
must be removed in order to change the brake pads.
The inboard brake pad of the RH (right-hand) brake incorporates a wear sensor.

BRAKE PAD WEAR SENSORS

The brake pad wear sensor is wired in series with a wear sensor on the LH (left-hand) front brake and the instrument cluster. If
the thickness of one of the brake pads connected to a wear sensor decreases to a predetermined limit, the instrument cluster
illuminates the brake warning indicator.

Published: 11-May-2011
Anti-Lock Control - Stability Assist - Anti-Lock Control - Stability Assist - Overview
Description and Operation

Overview

The ABS (anti-lock brake system) and DSC (dynamic stability control) system features a Bosch modulator, which is an
integrated four-channel HCU (hydraulic control unit) and ABS module. The unit is located in the rear of the engine compartment on the passenger side, and is installed in the brake hydraulic circuit between the brake master cylinder and the four brake
calipers.

The ABS module is connected to the high speed CAN (controller area network) bus, and actively interacts with other vehicle system control modules and associated sensors to receive and transmit current vehicle operating information.

When required, the ABS module will actively intervene and operate the HCU during braking or vehicle maneuvers to correct the vehicle attitude, stability, traction or speed. During incidents of vehicle correction, the ABS module may also request the ECM (engine control module) to control engine power in order to further stabilize and correct the vehicle.
To provide full system functionality, the ABS and DSC system comprise the following components: DSC switch.
Four wheel speed sensors.
Steering angle sensor.
Yaw rate and lateral acceleration sensor.
Stoplamp switch.
Instrument cluster indicator lamps.
Integrated ABS module and HCU. Brake booster vacuum sensor (3.0L vehicles only).

Two variants of ABS module are available, Bosch ESP®8.1 and Bosch ESP®plus8.1. The Bosch ESP®plus8.1 system is fitted to vehicles with ACC (adaptive cruise control) and incorporates a new feature to Jaguar known as 'electronic brake prefill'.

Electronic brake prefill, senses any rapid throttle lift off, activating a small brake hydraulic pressure build-up of approximately 3
to 5 bar (43.5 to 72.5 lbf/in²) in anticipation of the brakes being applied. This application produces a quicker brake pedal
response and consequently slightly shorter stopping distances. When the ECM detects rapid throttle lift off it signals the ABS module which controls the HCU to apply a low brake pressure to assist in a quicker brake application.

NOTE: All vehicles with ACC are supported by the Bosch ESP®plus8.1 system.

The ABS provides the following brake functions that are designed to assist the vehicle or aid the driver: ABS. DSC, including Trac DSC.
CBC (corner brake control).
EBD (electronic brake force distribution).
ETC (electronic traction control).
EBA (emergency brake assist).
EDC (engine drag-torque control).
Understeer control.
Electronic brake prefill (vehicles with ACC only).
Brake vacuum assist (3.0L vehicles only).

All the brake functions listed are automatically active when the ignition is in power mode and the engine is running. The DSC
system can be selected to off using the DSC switch.


WARNING: Although the vehicle is fitted with DSC, it remains the drivers responsibility to drive safely according to the
prevailing conditions.