Symptom Chart

WARNING: This page is about a different car, the 2004 Lincoln LS. However, it is still accessible from the selected car via links, so may be relevant.

PROBLEM SYMPTOM CHART

Condition	Possible Sources	Action
The red brake warning indicator is always on	Brake fluid level. Electronic parking brake (EPB). Circuit. Instrument cluster.	FILL the brake fluid reservoir to the MAX line. CHECK that the parking brake system is fully released. Go To PINPOINT TEST A: THE RED BRAKE WARNING INDICATOR LAMP STAYS ON .
Electronic parking brake (EPB) switch yellow indicator is always ON	EPB system.	CHECK the EPB module for DTCs. REFER to the ELECTRONIC PARKING BRAKE (EPB) SYSTEM DIAGNOSTIC TROUBLE CODE (DTC) INDEX .
Red brake warning indicator inoperative	Circuit. Bulb.	REFER to INFORMATION, GAUGES & WARNING DEVICES .
The brakes pull or drift	Tire air pressure. Brake pads. Brake components. Suspension component. Wheel alignment.	CHECK the tires for uneven or excessive wear, and correct inflation. CHECK the brake pads for uneven taper or excessive wear. REPAIR as necessary. CHECK the brake discs and the hubs for damage. REPAIR as necessary. CHECK wheel alignment. REFER to SPECIFICATIONS & PROCEDURES .
Brake pedal goes down fast	Brake fluid level. Air in system. Brake master cylinder.	INSPECT the system for leaks. FILL the brake master cylinder reservoir. BLEED the system. REFER to BRAKE SYSTEM BLEEDING . INSPECT the system for leaks. BLEED the system. REFER to BRAKE SYSTEM BLEEDING . CARRY OUT the Brake Master Cylinder Component Test. See BRAKE MASTER CYLINDER - BY-PASS CONDITION TEST .
The brake pedal eases down slowly	Air in system. Brake master cylinder.	INSPECT the system for leaks. BLEED the system. REFER to BRAKE SYSTEM BLEEDING . CARRY OUT the Brake Master Cylinder Component Test. See BRAKE MASTER CYLINDER - BY-PASS CONDITION TEST .
Brake lockup under light brake pedal force	Brake pads. Brake component. Parking brake component. Anti-lock brake control system.	CHECK the brake pads for uneven taper or excessive wear. REPAIR as necessary. CHECK the brake components for correct operation. REPAIR as necessary. REPAIR or INSTALL new components as necessary. REFER to PARKING BRAKE . CHECK the anti-lock brake control system. REFER to ANTI-LOCK CONTROL .
Excessive/erratic brake pedal travel	Leak in hydraulic system. Air in system. Disc brake caliper. Brake master cylinder. Brake pads Brake pedal.	INSPECT the system for leaks. BLEED the system. REFER to BRAKE SYSTEM BLEEDING . CARRY OUT the Brake Master Cylinder Component Test. See BRAKE MASTER CYLINDER - BY-PASS CONDITION TEST . CHECK the brake pads for excessive wear. CHECK the brake pedal for binding or obstructions. REPAIR as necessary.
Brakes drag	Parking brake component. Brake caliper guide pins. Disc brake caliper. Brake booster. Brake master cylinder.	REPAIR or INSTALL new components as necessary. REFER to PARKING BRAKE . REPAIR or INSTALL new caliper guide pins, seals and boots. REFER to BRAKE CALIPER GUIDE PINS . REPAIR or INSTALL new brake calipers as necessary. REFER to FRONT DISC BRAKE or REAR DISC BRAKE . CARRY OUT the Brake Booster Component Test. See BRAKE BOOSTER . CARRY OUT the Brake Master Cylinder Component Test. See BRAKE MASTER CYLINDER - BY-PASS CONDITION TEST .
Excessive brake pedal effort	Brake booster. Brake booster check valve. Brake booster manifold vacuum hose.	CARRY OUT the Brake Booster Component Test. See BRAKE BOOSTER . CARRY OUT the Check Valve Component Test. See CHECK VALVE . REROUTE, REPAIR or INSTALL new components as necessary.
The adjustable pedal does not operate	Adjustable pedal motor. Circuit(s). Adjustable pedal motor cables. Manual switch. Front electronic module (FEM) module.	Go To PINPOINT TEST C: THE ADJUSTABLE PEDAL DOES NOT OPERATE . REFER to the FRONT ELECTRONIC MODULE (FEM) DIAGNOSTIC TROUBLE CODE (DTC) INDEX .
Rattling noise	Caliper mounting bolts loose. Damaged or worn caliper guide pins or retainers. Missing or damaged anti-rattle clips or springs. Loose brake disc shield.	CHECK the caliper bolts. TIGHTEN to specifications. REFER to FRONT DISC BRAKE or REAR DISC BRAKE in this Section CHECK the caliper guide pins and retainers for lubrication and correct operation. LUBRICATE or INSTALL new components as necessary. REFER to BRAKE CALIPER GUIDE PINS . CHECK the brake pads for missing clips or broken springs. INSTALL new components as necessary. REFER to FRONT DISC BRAKE or REAR DISC BRAKE . TIGHTEN the brake disc shield bolts to specification. REFER to FRONT DISC BRAKE or REAR DISC BRAKE .
Clicking noise - with brakes applied with anti-lock brake system (ABS) brakes	ABS hydraulic control unit (HCU).	Acceptable condition.
Squealing noise - occurs on first (morning) brake application	Brake pads.	Acceptable condition. Caused by humidity and low brake pad temperature.
Squealing noise - a continuous squeal	Brake pads or linings worn below minimum thickness.	INSPECT brake pads for excessive wear, taper wear or uneven wear. VERIFY brake pads are within minimum specifications. REFER to BRAKE PADS .
Squealing noise - an intermittent squeal brought on by cold, heat, water, mud or snow	Brake pad	Acceptable condition.
Groaning noise - occurs at low speeds with brake lightly applied (creeping)	Brake pads	Acceptable condition.
Grinding noise - continuous	Brake pads or linings worn below minimum thickness	INSPECT the brake pads, brake discs and attaching hardware for damage. VERIFY brake pads are within minimum specifications. REFER to BRAKE PADS .
Moaning noise	Brake linings contaminated with grease or oil	INSPECT the brake pads for contamination. REPAIR or INSTALL new components as necessary. REFER to FRONT DISC BRAKE or REAR DISC BRAKE .
NOTE: The driver door module (DDM) controls the vehicle memory system. The front electronic module (FEM) sends and receives memory information to/from the DDM through the standard corporate protocol (SCP) communication network. If a system fault cannot be corrected, refer to MODULE COMMUNICATIONS NETWORK for further diagnosis. The adjustable pedal memory function does not operate - manual switch commands functional	Circuit(s) Adjustable pedal potentiometer. FEM.	Go To PINPOINT TEST D: DTC B1990: PEDAL FORWARD/REARWARD POTENTIOMETER FEEDBACK CIRCUIT FAILURE .
Vibration when the brakes are applied	Uneven brake pad wear. Brake disc pad transfer. Brake disc. Suspension components.	COMPLETE the brake system inspection described in INSPECTION & VERIFICATION . Go To PINPOINT TEST P: VIBRATION WHEN THE BRAKES ARE APPLIED .
Brake vibration/shudder - occurs when the brake pedal is released	Brake caliper guide pins. Brake drag.	INSPECT the brake caliper guide pins for correct operation. REFER to BRAKE CALIPER GUIDE PINS . INSPECT the brake pads for premature wear. REPAIR or INSTALL a new caliper as necessary. REFER to FRONT DISC BRAKE or REAR DISC BRAKE .