PSA HYbrid4

HYbrid4
Company type	Hybrid drivetrain system
Industry	Automotive
Founded	2011
Founder	PSA Peugeot-Citroën and Ford
Area served	Worldwide
Products	Hybrid drivetrain systems for vehicles

Adapted from the English Wikipedia article PSA HYbrid4, available under CC BY-SA 4.0Updated 10 August 2025

HYbrid4 represents the exclusive TTR hybrid drivetrain developed by PSA Peugeot-Citroën in collaboration with Ford. This system merges a diesel engine powering the front axle with an electric motor driving the rear wheels, creating a four-wheel-drive hybrid setup with a modest all-electric capability. Launched in 2011 with the Peugeot 3008 HYbrid4, it achieves CO₂ emissions of 99 g/km and fuel efficiency of 3.8 L/100 km, surpassing rivals such as the smaller Toyota Prius. Drivers can select among four modes: Auto, Sport, ZEV (zero-emission electric), and 4WD.

The initial HYbrid4 generation was produced from 2011 through 2017. A renewed plug-in HYbrid/HYbrid4 system debuted in 2020, offering front-wheel or all-wheel drive options with power outputs spanning from 180 hp (308 1.6 HYbrid) up to 360 hp (508 PSE).

Operation

The HYbrid4 powertrain integrates a 2.0-litre HDi FAP EURO5 diesel engine delivering 120 kW/163 hp (DW10CTED4 jointly developed by PSA and Ford) alongside a 28 kW (37 hp) electric motor. It functions across four distinct driving modes:

AUTO focuses on maximizing fuel efficiency by shifting gears early and frequently engaging ZEV mode;

SPORT provides a combined output of 200 hp (150 kW) and 500 Nm torque up to speeds of 120 km/h, featuring responsive throttle input and elevated engine revs before gear changes;

4WD ensures continuous all-wheel drive by keeping the diesel engine running to charge the battery, distributing torque approximately 60% to the front and 40% to the rear wheels at speeds up to 120 km/h;

ZEV allows pure electric propulsion via the rear motor when battery charge is at least one-third full, limited to roughly 60 km/h and around a 2 km range; accelerating beyond a preset threshold restarts the diesel engine and reverts control to AUTO mode.

Auto Start-Stop functionality is incorporated except during 4WD mode, shutting off the engine during coasting or stops to conserve fuel. The system employs a BOSCH SMG reversible starter-generator that facilitates instantaneous restarts as necessary for power demands, battery charging, or air conditioning operation.

HV Battery

The high-voltage battery pack consists of 42 modules, each containing four D-size SANYO cells. It has a nominal voltage of 201.6 V, a capacity of 1.1 kWh, and peak power delivery of 31 kW. The operating voltage varies between approximately 150 V and 270 V depending on state of charge and load. To enhance battery longevity, the hybrid control unit (HCU) restricts charging to a maximum of 90% and discharging down to no less than 30%. An independent air cooling system with adjustable airflow manages thermal conditions and can function even when the vehicle is locked, producing audible airflow and warm air from the left rear quarter panel.

Typically, this HV battery endures for between 150,000 and 200,000 kilometers or about six to ten years before significant capacity degradation occurs. Although reduced battery performance diminishes electric range and fuel savings, full four-wheel-drive capability remains unaffected.

Rear electric drive

Developed jointly by PSA Peugeot-Citroën, Bosch, and GKN, the rear electric drive unit incorporates an integrated clutch that disengages above speeds of 120 km/h to minimize drag and enhance fuel efficiency on highways. Instead of a mechanical reverse gear, reversing is achieved by inverting the motor’s electrical current.

Bosch SMG in HYbrid4

The HYbrid4 system utilizes the Bosch SMG ("separate motor generator") 180/120 electric motor as its primary traction unit. This permanent magnet synchronous motor, weighing 32 kg, produces a maximum output of 27 kW and 200 Nm of torque. It contributes to improved fuel economy in AUTO and ZEV modes, enhances traction when operating in 4WD, and boosts acceleration performance in SPORT mode. Additionally, this motor is featured as the main traction motor in the Fiat 500e and powers the front axle of the Porsche 918 Spyder.

Within the HYbrid4 architecture, the Bosch SMG 138/80 motor functions as a high-voltage starter/alternator. It supports start-stop operations, drives the rear wheels, and recharges the high-voltage battery.

Common problems and known faults

Typical challenges encountered with the HYbrid4 system include:

Jerky and delayed gear changes from the BMP6 automated manual transmission, which can often be corrected by adjusting the clutch and gear selector through DiagBOX diagnostics.

Rear electric drive noise caused by deteriorating reducer bearings; despite manufacturer claims of "no servicing," it is advisable to perform oil maintenance every 30,000 to 50,000 km.

Loss of propulsion where the engine idles without responding to accelerator input, frequently due to neglected oil changes in the robotized gearbox.

Failure of the HDI engine to shut off accompanied by an "ELECTRIC MODE CURRENTLY UNAVAILABLE" warning; this issue is associated with an accessory belt timer that disables start-stop functionality after approximately 60,000 km. The timer can be reset if the belt remains intact; otherwise, replacement is necessary.

Premature wear or failure of the accessory belt resulting from incorrect tension settings.

Rapid fluctuations in battery state-of-charge caused by failing nickel-metal hydride (NiMH) cells; resolving this requires replacing defective cells and updating HV battery ECU software to mitigate accelerated battery degradation.

Bearing failure in the Bosch SMG 138/80 starter/alternator, which can lead to accessory belt breakage.

Production

Concept

2008 Peugeot RC HYbrid4
2009 Peugeot RCZ HYbrid4 concept
2010 Peugeot HR1 (petrol engine)
2010 Peugeot SR1
2011 Peugeot HX1