Symptom Table - Brake System (Hybrid Vehicles)

WARNING: This page is about a different car, the 2010 Mercury Milan, 2010 Lincoln MKZ, and 2010 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.

SYMPTOM TABLE - BRAKE SYSTEM (HYBRID VEHICLES)

Condition	Possible Sources	Action
The red brake warning indicator and the yellow ABS warning indicator are illuminated	DTCs in the ABS module	REFER to ANTI-LOCK CONTROL -- HYBRID to diagnose the ABS.
The red brake warning indicator is always/never on	Brake fluid level switch Parking brake switch Wiring, terminals or connectors Instrument Cluster (IC) Smart Junction Box (SJB) DTCs present in the ABS module Vacuum sensor	REFER to PINPOINT TEST S: THE BRAKE WARNING INDICATOR IS NEVER ON and/or PINPOINT TEST T: THE BRAKE WARNING INDICATOR IS ALWAYS ON to diagnose the red brake warning indicator.
Brakes drag	Parking brake component	REFER to PARKING BRAKE to diagnose the parking brake system.
	Brake caliper and/or guide pins Brake flexible hose	INSPECT the brake system components. REFER to BRAKE SYSTEM INSPECTION .
	Brake booster Brake master cylinder	CARRY OUT the BRAKE MASTER CYLINDER - Compensator Port .
	Pedal assembly	RETRIEVE and RECORD any ABS module DTCs, REFER to DTC TABLES . INSTALL new components as necessary.
	Hydraulic Control Unit (HCU)	REFER to DIAGNOSIS AND TESTING to diagnose the HCU .
Brakes lock up under light brake pedal force	Brake calipers and/or guide pins Brake flexible hose Brake pads Brake discs	INSPECT the brake system components. REFER to BRAKE SYSTEM INSPECTION .
	Pedal assembly	RETRIEVE and RECORD any ABS module DTCs, REFER to ABS MODULE DTC TABLE . INSTALL new components as necessary.
	ABS	REFER to ANTI-LOCK CONTROL -- HYBRID to diagnose the ABS.
Vehicle pulls or drifts during braking	Brake calipers and/or guide pins Brake flexible hose Brake pads Brake discs	INSPECT the brake system components. REFER to BRAKE SYSTEM INSPECTION .
	Tires	REFER to WHEELS AND TIRES to diagnose tire concerns.
	Suspension component(s) and/or wheel alignment	REFER to SUSPENSION SYSTEM to diagnose suspension system.
Excessive brake pedal travel (low/spongy pedal)	Brake pedal assembly Brake booster Wiring terminals or connectors ABS	RETRIEVE and RECORD any ABS module DTCs, REFER to ABS MODULE DTC TABLE . INSTALL new components as necessary.
Excessive brake pedal effort	Brake pedal assembly Vacuum source Brake booster manifold vacuum hose Brake booster Brake booster check valve	RETRIEVE and RECORD any ABS module DTCs, REFER to ABS MODULE DTC TABLE . INSTALL new components as necessary.
Excessive brake pedal effort	Brake pads	INSPECT the brake pads. REFER to BRAKE SYSTEM INSPECTION .