Engine Disconnect Clutch

WARNING: This page is about a different car, the 2021 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.

Principles of Operation

For engine disconnect clutch operation, REFER to: Hybrid Drive Unit .

NOTE: If the transmission fluid auxiliary pump or the hybrid drive unit is replaced, the Transmission Strategy Download and the Adaptive Learning Drive Cycle procedures must be carried out before returning the vehicle to the customer. Otherwise harsh or slipping engine engagements may occur.

Condition	Possible Sources	Action
Engine disconnect clutch does not apply	Engine disconnect clutch solenoid is mechanically stuck OFF	REMOVE and INSPECT the engine disconnect clutch solenoid. If the solenoid is stuck off, INSTALL a new transmission fluid auxiliary pump. REFER to: Transmission Fluid Auxiliary Pump .
	Engine disconnect clutch control valve stuck OFF	DISASSEMBLE, CLEAN and INSPECT the engine disconnect clutch control valve. If the bore or valve is damaged, INSTALL a new transmission fluid auxiliary pump. REFER to: Transmission Fluid Auxiliary Pump .
	Engine disconnect clutch hydraulic circuit blocked/leaking	REMOVE the transmission fluid pan. INSPECT the hybrid drive unit feed tubes and seals for damage/debris/blockage/leaks. CLEAN or REPLACE components as necessary. REFER to: Transmission Fluid Pan, Gasket and Filter .
		CARRY OUT an air pressure test of the engine disconnect clutch. The results of this test will indicate the condition of the hydraulic passages in the hybrid drive unit. REFER to: Special Testing Procedures .
		REMOVE the transmission fluid auxiliary pump. INSPECT the gasket and mating surfaces for damage/leaks. INSPECT the hydraulic passages for debris/blockage. INSPECT the check balls for sitcking/damage/missing. CLEAN or REPLACE components as necessary. REFER to: Transmission Fluid Auxiliary Pump .
		REMOVE the hybrid drive unit. INSPECT the gasket and mating surfaces for damage/leaks. INSPECT the hydraulic passages for debris/blockage. CLEAN or REPLACE components as necessary. REFER to: Hybrid Drive Unit .
	Engine disconnect clutch piston, seals or friction plates	Only after all other system components have been inspected and confirmed to be functioning properly, INSTALL a new hybrid drive unit. REFER to: (303-01G Electric Motor - 3.5L V6 PowerBoost (CN), Removal and Installation).
Engine disconnect clutch is always applied	Engine disconnect clutch solenoid mechanically stuck ON	REMOVE and INSPECT the engine disconnect clutch solenoid. If the solenoid is stuck on, INSTALL a new transmission fluid auxiliary pump. REFER to: Transmission Fluid Auxiliary Pump .
	Engine disconnect clutch control valve stuck ON	DISASSEMBLE, CLEAN and INSPECT the engine disconnect clutch control valve. If the bore or valve is damaged, INSTALL a transmission fluid auxiliary pump. REFER to: Transmission Fluid Auxiliary Pump .
	Engine disconnect clutch hydraulic circuit blocked/cross leaks	REMOVE the transmission fluid pan. INSPECT the hybrid drive unit feed tubes and seals for damage/debris/blockage. CLEAN or REPLACE components as necessary. REFER to: Transmission Fluid Pan, Gasket and Filter .
		CARRY OUT an air pressure test of the engine disconnect clutch. The results of this test will indicate the condition of the hydraulic passages in the hybrid drive unit. REFER to: Special Testing Procedures .
		REMOVE the transmission fluid auxiliary pump. INSPECT the gasket and mating surfaces for damage/leaks. INSPECT the hydraulic passages for debris/blockage. INSPECT the check balls for sitcking/damage/missing. CLEAN or REPLACE components as necessary. REFER to: Transmission Fluid Auxiliary Pump .
		REMOVE the hybrid drive unit. INSPECT the hydraulic passages for debris/blockage. CLEAN or REPLACE components as necessary. REFER to: Hybrid Drive Unit .
	Engine disconnect clutch return springs or friction plates	Only after all other system components have been inspected and confirmed to be functioning properly, INSTALL a new hybrid drive unit. REFER to: (303-01G Electric Motor - 3.5L V6 PowerBoost (CN), Removal and Installation).
Engine disconnect clutch delayed/soft/slipping apply	Incorrect transmission strategy programmed into PCM/ TCM.	CARRY OUT the Transmission Strategy Download. REFER to: Transmission Strategy Download .
	Low line pressure	CARRY OUT the line pressure test. If line pressure is low, REFER to the Line Pressure Diagnosis Chart. REFER to: Special Testing Procedures .
	Engine disconnect clutch solenoid mechanically sticking	REMOVE and INSPECT the engine disconnect clutch solenoid. If the solenoid is sticking or damaged, INSTALL a new transmission fluid auxiliary pump. REFER to: Transmission Fluid Auxiliary Pump .
	Engine disconnect clutch control valve sticking	DISASSEMBLE, CLEAN and INSPECT the engine disconnect clutch control valve. If the bore or valve is damaged, INSTALL a new transmission fluid auxiliary pump. REFER to: Transmission Fluid Auxiliary Pump .
	Engine disconnect clutch hydraulic circuit blocked/leaking	REMOVE the transmission fluid pan. INSPECT the hybrid drive unit feed tubes and seals for damage/debris/blockage/leaks. CLEAN or REPLACE components as necessary. REFER to: Transmission Fluid Pan, Gasket and Filter .
		CARRY OUT an air pressure test of the engine disconnect clutch. The results of this test will indicate the condition of the hydraulic passages in the hybrid drive unit. REFER to: Special Testing Procedures .
		REMOVE the transmission fluid auxiliary pump. INSPECT the gasket and mating surfaces for damage/leaks. INSPECT the hydraulic passages for debris/blockage. INSPECT the check balls for sitcking/damage/missing. CLEAN or REPLACE components as necessary. REFER to: Transmission Fluid Auxiliary Pump .
		REMOVE the hybrid drive unit. INSPECT the gasket and mating surfaces for damage/leaks. INSPECT the hydraulic passages for debris/blockage. CLEAN or REPLACE components as necessary. REFER to: Hybrid Drive Unit .
	Engine disconnect clutch piston, seals or friction plates	Only after all other system components have been inspected and confirmed to be functioning properly, INSTALL a new hybrid drive unit. REFER to: (303-01G Electric Motor - 3.5L V6 PowerBoost (CN), Removal and Installation).
Engine disconnect clutch harsh apply	Incorrect transmission strategy programmed into PCM/ TCM.	CARRY OUT the Transmission Strategy Download. REFER to: Transmission Strategy Download .
	High line pressure	CARRY OUT the line pressure test. If line pressure is high, REFER to the Line Pressure Diagnosis Chart. REFER to: Special Testing Procedures .
	Engine disconnect clutch solenoid mechanically sticking	REMOVE and INSPECT the engine disconnect clutch solenoid. If the solenoid is sticking or damaged, INSTALL a new transmission fluid auxiliary pump. REFER to: Transmission Fluid Auxiliary Pump .
	Engine disconnect clutch control valve sticking	DISASSEMBLE, CLEAN and INSPECT the engine disconnect clutch control valve. If the bore or valve is damaged, INSTALL a new transmission fluid auxiliary pump. REFER to: Transmission Fluid Auxiliary Pump .
	Engine disconnect clutch hydraulic circuit blocked/leaking	REMOVE the transmission fluid pan. INSPECT the hybrid drive unit feed tubes and seals for damage/debris/blockage. CLEAN or REPLACE components as necessary. REFER to: Transmission Fluid Pan, Gasket and Filter .
		CARRY OUT an air pressure test of the engine disconnect clutch. The results of this test will indicate the condition of the hydraulic passages in the hybrid drive unit. REFER to: Special Testing Procedures .
		REMOVE the transmission fluid auxiliary pump. INSPECT the gasket and mating surfaces for damage/leaks. INSPECT the hydraulic passages for debris/blockage. INSPECT the check balls for sitcking/damage/missing. CLEAN or REPLACE components as necessary. REFER to: Transmission Fluid Auxiliary Pump .
		REMOVE the hybrid drive unit. INSPECT the gasket and mating surfaces for damage/leaks. INSPECT the hydraulic passages for debris/blockage. CLEAN or REPLACE components as necessary. REFER to: Hybrid Drive Unit .
	Engine disconnect clutch piston, return springs or friction plates	Only after all other system components have been inspected and confirmed to be functioning properly, INSTALL a new hybrid drive unit. REFER to: (303-01G Electric Motor - 3.5L V6 PowerBoost (CN), Removal and Installation).