Federal Investigation Focuses on Stalling Chrysler Pacifica Hybrid Models

The Chrysler Pacifica Hybrid is at the center of a federal investigation after multiple complaints regarding the vehicle stalling at speed. The National Highway Traffic Safety Administration (NHTSA) has received at least 40 complaints from owners of 2019-2021 Pacifica Plug-In Hybrid electric vehicles (PHEVs). Just a fraction of those Chrylser Pacifica Hybrid models are included in the investigation.

Chrysler Pacifica Hybrid transmission failures 

The 2021 Chrysler Pacifica Pinnacle Hybrid features new Platinum Chrome 18-inch wheels.
2021 Chrysler Pacifica Hybrid | Stellantis

According to CarComplaints.com, consumers noted that “all motive power disappeared” when their Chrysler Pacifica Hybrid model traveled over 25 mph. The NHTSA adds that stalling issues originate from malfunctioning transmissions. This also causes a dashboard message to alert drivers about an internal transmission failure and a problem with charging capabilities.  

In one video uploaded by a Pacifica Hybrid owner, his “accelerator stopped responding.” The digital dash cluster then showed a message stating “Service Charging System” and “Shift to ‘P’ to Start.” His video and the online testimony of other Pacifica Hybrid owners explain that the vehicles must be shut off and turned back on after waiting roughly one minute. The owner, who reported 19 breakdowns over 8,000 miles, was granted a buyback from Chrysler.

In late 2021, filed complaints increased, but current model Pacifica Hybrids are unaffected. Nevertheless, the NHTSA is set to determine if the defect exists, thus implementing a recall for repairs.

How the Chrysler Pacifica Hybrid system transmission works

The Pacifica Hybrid has a front-wheel-drive electronically-variable transaxle gearbox, known as an SI-EVT, Allpar reports. It has a myriad of internal and external electronic controllers and a two-motor system running on a three-phase alternating current (AC). The frequency of which determines the motors’ speed, thus controlling torque output. To manage electric drive and regenerative braking, a two-processor Power Inverter Module (PIM) on top of the transmission case converts energy from the direct current (DC) battery to AC to drive the electric motors. Additionally, the PIM converts AC power back to DC to charge the battery.  

The PIM’s two processors—the Hybrid control Processor (HCP) and Auxiliary Hybrid Control Processor (AHCP)—control Motor 1 and Motor 2, respectively. Motor 1, mechanically connected to the input, is the main driving apparatus. Motor 2, mechanically connected to the output, handles all other functions.

Regardless, the SI-EVT has relatively conventional mechanics. It has an input-side, four-pinion single planetary gear with a clutch-operated sun gear connected to Motor 2. The planetary gear is mated to the output ring gear on the transaxle’s differential. This supplies mechanical power from the Pacifica Hybrid’s 3.6-liter Pentastar engine or Motor 2 to the front wheels. In fully-electric modes, Motor 1’s transfer pinion gear is directly connected to the output ring gear on the differential to drive the front wheels.

Who manufactures the Chrysler Pacifica Hybrid’s SI-EVT? 

Allpar reports that then-FCA, now Stellantis, sought technical advice from the consulting firm Ricardo, who designed the system based on previously-patented units by Timken with Ricardo. Although the unit is assembled at the Tipton Transmission Plant, the case and internal gears are made at Kokomo Transmission.

Global component manufacturer KKR & Co.—the results of a 2019 merger between parts manufacturer Magneti Marelli and Nissan subsidiary Calsonic Kansei—one of Stellantis’ largest suppliers, is said to have provided some of the electronics and parts for the SI-EVT. Nevertheless, the unit is also made up of South Korean company LG Chem’s liquid-cooled battery and multiple presumed Chinese vendors for ancillary parts.

Stellantis cooperating in multiple federal investigations 

The deeply sculpted and athletic new front grille of the 2021 Chrysler Pacifica Pinnacle Hybrid is accented with a Platinum Chrome grille surround.
Chrysler Logo | Stellantis

Customer issues with the SI-EVT are just one of three active investigations into possible faults with Chrysler’s parent company Stellantis. A report from AP claims three active investigations affect over 1.65 million vehicles under the company’s umbrella.

  • 1.34 million Jeep Cherokees model years 2014-2020: faulty electronic parking brakes
  • 289,000 Dodge Journey, Jeep Compass, and Jeep Patriot model year 2016: engine crankshaft or camshaft sensor problems
  • 21,300 Chrysler Pacifica PHEV model years 2019-2021: electrical transmission failure

No crashes or injuries have been reported in all three cases. Stellantis is reportedly cooperating with federal investigators.

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