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48V Belt Starter Generators and Mild-Hybrid Belt Kits

48V belt starter generators and belt kits for Ram eTorque, Jeep eTorque and Audi mild hybrids. Send your VIN and we tell you before you pay whether we can get the exact unit, what it costs and when it ships.

What a 48V belt starter generator does

It takes the place of the alternator. It charges a separate 48-volt battery, restarts the engine in stop-start traffic, adds a little torque as you pull away, and recovers energy when you slow down. Because the belt now carries torque in both directions, these engines use their own belt and tensioner, and an ordinary accessory belt is not a substitute.

When one fails, the engine warning light usually comes on first, often with a message about the 48-volt supply or the drive system. Some will not restart at all.

Which vehicles have one

  • Ram 1500 from 2019 with the 3.6-liter V6 eTorque, and with the 5.7-liter HEMI V8 eTorque until the HEMI left the Ram 1500 in the 2025 update. Ram calls the unit the motor generator unit, or MGU.
  • Jeep Wrangler JL with eTorque: on the 2.0-liter turbo, which Jeep dropped in 2020, and on the 3.6-liter V6 where the option was fitted. Continental supplies the 48-volt unit.
  • Audi's 48-volt mild hybrids since 2019, which use a belt-driven starter-alternator — among them the A7, A8, Q7 and Q8.

Not on this list, on purpose: Mercedes-Benz EQ Boost on the six-cylinder engines. It is a 48-volt mild hybrid, but its starter generator sits between the engine and the transmission rather than on the belt, so a belt starter generator is not the part those cars need. If you are not sure which kind yours has, the VIN settles it.

What Ram owners report

Owners of 2019–2023 Ram 1500s have filed 223 complaints with NHTSA, the US federal vehicle-safety regulator, that mention eTorque, the 48-volt system or the motor generator unit. By model year, as of September 18, 2026:

  • 2019 Ram 1500: 39 complaints
  • 2020 Ram 1500: 51 complaints
  • 2021 Ram 1500: 64 complaints
  • 2022 Ram 1500: 59 complaints
  • 2023 Ram 1500: 10 complaints

NHTSA publishes complaints as owners wrote them and does not verify them. Newer trucks have had fewer years on the road to collect them. What the complaints describe again and again is not only the failure but the wait for the part:

A 2021 Ram 1500 owner, NHTSA complaint 11747020: "Dealer service center found the eTorque to be bad and i was told not to drive it. And there is no fix or parts for it. Not sure when or if they will get the parts."

A 2020 Ram 1500 owner, NHTSA complaint 11729964: "In april of 2024 the MGU on the etourqe system needed replacement. The vehicle went into the shop on April 26 2024 and was released to me on may 16 2024."

Recalls to check before you buy anything

  • 19V142000, 2019 Ram 1500 with the 48-volt auxiliary battery behind the rear seat (sales code XBZ): the battery wire terminal connection may overheat, with a risk of fire in the cab even with the ignition off. Dealers secure the fasteners free of charge.
  • 23V265000, 2021 Ram 1500 with the 5.7-liter eTorque: the powertrain control module software may cause an incorrect fuel mixture and an engine stall. Dealers update the software free of charge.

A stall or a dead 48-volt system is not always the generator. Check your VIN at nhtsa.gov/recalls first — a recall repair costs you nothing, and we would rather you got that than bought a generator you did not need.

Replacing one

From SEG Automotive's replacement guidance:

  1. Switch the engine off, wait, then disconnect both the 12-volt and the 48-volt batteries.
  2. Check for zero volts at the generator's connector before touching it.
  3. On a liquid-cooled unit, drain the coolant before the lines come off.
  4. Install the new unit and its belt, torque the fasteners to the maker's figures, and reconnect both batteries.
  5. Connect the unit to a scan tool and load the current software. A new generator that has not been set up is not finished.

On Audi's system the 12-volt side is fed from the 48-volt side through a converter, so the car is only fully de-energized once the 48-volt side is. Audi's procedure does that with a scan tool.

What we source

The four units listed below are our range: an SEG and a Valeo belt starter generator, and 48-volt belt kits from Gates and Continental, $314.99 to $1,031.99. The generator a particular truck or car takes is specific to its engine, and owners report long dealer waits for it. Send the VIN, and before you pay we tell you whether we can get the unit, what it costs and when it ships. If a part we confirmed as a fit does not fit your vehicle, we cover the return and the replacement.

Checked

4 parts in our range