2019 Tesla Model 3 Serpentine Belt Routing & Length

As an ASE-certified master technician, I get all kinds of questions from drivers who are transitioning from traditional internal combustion engine (ICE) vehicles to electric vehicles (EVs). One of the most common maintenance inquiries we see involves standard wear items. If you are looking for the serpentine belt routing diagram and replacement guide for a 2019 Tesla Model 3, you are in for a very pleasant surprise.

Unlike a traditional gas-powered car, the 2019 Tesla Model 3 is a fully electric battery vehicle (BEV). It does not have a traditional engine, and therefore, it does not have a serpentine belt.

Below, we’ll use our standard maintenance guide format to explain exactly how the Model 3 replaces the functions of a traditional serpentine belt system, what parts drive your accessories, and what you should actually be looking out for.

Quick answer

Because the 2019 Tesla Model 3 has no internal combustion engine, it lacks the pulleys and drive belts found on traditional cars. Here are the specifications (or lack thereof) for this vehicle:

• Belt length: Not Applicable
• Rib count: None (0-rib)
• OEM belt PN: None
• Aftermarket cross-refs: None (No Gates, Dayco, or Continental equivalents exist)
• Auto-tensioner PN: None
• Idler pulley PN: None

Belt routing

In a traditional gas vehicle, the serpentine belt routing path typically runs from the crankshaft pulley → A/C compressor → idler pulley → alternator → power steering pump → water pump → tensioner. We usually recommend taking a photograph of the existing belt before removal to ensure you route the new one correctly.

However, on a 2019 Tesla Model 3, there is no routing path because none of these belt-driven components exist. Here is how the Tesla handles these systems without a serpentine belt:

• Crankshaft: Replaced by high-voltage electric drive motors attached directly to the gearboxes.
• A/C Compressor: The Model 3 uses a high-voltage electric A/C compressor powered directly by the main traction battery.
• Alternator: Instead of an alternator charging a 12V battery via a belt, the Model 3 uses a solid-state DC-to-DC converter to step down the high voltage from the main battery to charge the low-voltage (12V) system.
• Power Steering: The Model 3 uses an electric power assist steering (EPAS) rack. An electric motor mounted directly on the steering rack provides the assist, eliminating the need for hydraulic fluid, pumps, and belts.
• Water Pump: The complex thermal management system (which cools the battery pack, drive units, and computers) utilizes multiple highly efficient electric coolant pumps.

How to replace the serpentine belt

You get to skip this job entirely! There is no need for a serpentine belt tool or a 3/8" breaker bar to relieve tension, and no skinned knuckles from trying to snake a rubber belt down the front of an engine block. The accessory drive system has been completely digitized and electrified.

If you are looking to do standard DIY maintenance on your Model 3, your time is better spent rotating the tires, replacing the cabin air filters (which should be done every 2 years), topping off the windshield washer fluid, and checking your brake fluid for moisture content.

Replacement interval

Because there is no serpentine belt, there is no 60,000 to 90,000-mile replacement interval. You will never have to worry about a snapped belt leaving you stranded on the side of the road without power steering or alternator charging.

Signs of a failing belt or tensioner

While you won't hear the classic "belt squeal" or tensioner rattle on startup, the electric components that replace the belt-driven accessories can still exhibit signs of wear. Here is what to listen for on your 2019 Tesla Model 3:

• A/C Compressor noise: A loud vibrating, grinding, or whining noise from the front of the vehicle when the climate control or battery preconditioning is running can indicate a failing electric A/C compressor.
• Coolant pump failure: If the vehicle throws a thermal management error on the center screen, or you hear excessive, irregular humming from the electric coolant pumps, the vehicle may need a pump replacement.
• Steering stiffness: A heavy steering wheel usually points to an electrical fault in the EPAS rack or a low-voltage battery issue, rather than a broken drive belt.

If your EV is making strange noises or giving you error codes, don't try to pop the hood to look for a broken belt—you'll only find the "frunk" (front trunk). Instead, seek out a professional who is certified in high-voltage EV systems.

Find a trusted shop on Repairius.