Continuously variable transmissions (CVTs) are growing in popularity thanks to their improved fuel efficiency over conventional automatic transmissions. A key component that allows CVTs to shift through gear ratios seamlessly is the stepper motor.
This electronically controlled device precisely adjusts the pulleys and belts to vary the gear ratios. However, like any part, CVT stepper motors can eventually wear out and begin to fail. When this happens, some distinct symptoms indicate an underlying problem with the stepper motor.
This article will reveal the most common signs of a failing or faulty CVT stepper motor. We will explore what causes these problematic symptoms to occur, as well as the reasons why the stepper motor components deteriorate over time.
Table of Contents
Bad CVT Stepper Motor Symptoms
Harsh jerking from the transmission
- As engine rpm increases, the worn stepper motor cannot smoothly engage the appropriate pulley ratio.
- This causes abrupt transitions between gear ratios. This issue is more noticeable at low speeds.
Low power accelerations and flare-up RPMs
- Worn stepper motor components like sensors, gears and actuators cannot accurately align the pulley position.
- This causes slipping between pulleys and the inability to engage the intended gear ratio.
High-pitched whining-type noise when accelerating
- If the internal components of stepper motors, like gears, shafts and bearings, are out of shape. It creates friction and improper meshing with an audible gear whining.
Burning smell and hot transmission after driving
- Failed stepper motor components generate excess heat from friction.
- This can lead to overheating in the transmission and eventual failures as you keep driving without any repairs.
Visible leaks near the stepper motor
- Failed seals from wear allow fluid to leak out gradually.
- Once this happens, the low fluid causes increased heat and damage as a result.
Solutions For Bad CVT Stepper Motor Symptoms
- If symptoms of a failing CVT stepper motor are visible, have the trouble codes scanned at a repair shop to pinpoint the exact issue. Codes like P0740, P0730, and P0731 indicates problems in the stepper motor or transmission speed sensors.
- Replace any damaged or worn transmission belts or pulleys if needed, as slipped belts can place more strain on the stepper motor. Install reinforced high-quality belts to prevent future slipping.
- If the stepper motor is making grinding or whining noises, have the transmission fluid flushed and refilled to rule out low fluid or contamination issues.
- Consider installing an aftermarket transmission cooler or temperature gauge if the vehicle is prone to overheating. This can provide early warning of issues and reduce heat strain on the stepper.
- Replace the failing OEM CVT stepper motor with a remanufactured or new replacement unit that is built specifically for your vehicle model. Only use reputable branded parts to ensure reliability and performance.
- Use the manufacturer’s recommended transmission fluid and change intervals to protect the new stepper motor from premature wear and contamination.
FAQs About Bad CVT Stepper Motor Symptoms
Q: How does low transmission fluid relate to stepper motor failure?
A: Insufficient fluid allows the stepper motor to overheat from friction and wear at an accelerated rate. Low fluid also starves the transmission of needed lubrication. This increases strain on the stepper motor.
Q: Is it safe to drive with CVT stepper motor issues?
A: It is not ideal to continue driving once the significant symptoms appear. The transmission will eventually fail, possibly at dangerous speeds. Therefore, I suggest getting it inspected and fixed promptly.
Q: Does replacing the stepper motor require transmission removal?
A: In most cases, the transmission must be away from the engine to access and adequately replace the CVT stepper motor. So yes, this typically involves the removal of the entire transmission assembly.