Why Your 2020 Ram Shudders or Makes Noise (eTorque Generator Failure)

How to Fix Transmission Shudder

For 2020 Dodge Ram owners, a transmission shudder can be a disconcerting and potentially serious issue. While the term "shudder" can describe various sensations, from a vibration during gear changes to a rhythmic shaking under acceleration, the root cause in this model year is often linked to a specific component within the eTorque mild-hybrid system. Based on real owner experiences, a failing generator or Motor Generator Unit (MGU) is a primary culprit, especially in trucks equipped with this technology. As one owner shared after a string of bad luck: "In early-ish November I totaled my truck... less than 2 hours after buying the [new] truck the e-torque generator locked up on me." This guide will walk you through the symptoms, diagnosis, and repair based on actual data from Ram owners.

Symptoms

The symptoms of a failing component that leads to drivetrain shudder or severe vibration are often progressive and can be mistaken for transmission issues. Owners report a sudden, severe mechanical failure rather than a subtle shudder. The most dramatic symptom is a complete seizure of the eTorque generator, which will cause an immediate and catastrophic loss of auxiliary power and likely trigger a cascade of warning lights and drivability concerns. This isn't a mild vibration; it's a failure that renders the vehicle inoperable.

Prior to a complete lock-up, you might notice related symptoms that indicate stress on the belt-driven system. A persistent whirring, buzzing, or gravelly noise from the engine bay, particularly on startup or during the auto start/stop function, can be a precursor. This noise may be accompanied by a hissing sound, which could indicate a belt slip or a vacuum leak associated with the high-pressure system. While not a "shudder" in the traditional sense, these audible warnings are critical signs.

It is also vital to differentiate the issue from other common problems. Some owners mention exhaust noise or oil leaks, which are separate concerns but should be addressed as they can complicate diagnosis. The key symptom cluster for this specific failure centers on the eTorque system: unusual noises from the front of the engine, followed by a sudden mechanical lock-up that feels and sounds like a major breakdown, often requiring a tow. As an owner lamented after purchasing a used truck: "Just looking to see if there’s any other suggestions. Went a little over my price range but I fell in love with this truck... I need this baby to last me." This highlights the urgency of addressing strange symptoms early.

Most Likely Cause

Based on the aggregated owner reports, the most likely cause of a severe drivetrain disturbance or "shudder"-like event in the 2020 Dodge Ram is the failure of the eTorque Belt-Driven Hybrid Starter Generator. This system, which replaces a traditional alternator, provides torque assist, regenerative braking, and seamless engine start/stop. The generator, or Motor Generator Unit (MGU), is a complex component that can fail internally. When it seizes, as reported by multiple owners, it locks the serpentine belt, which can cause immediate engine stalling or severe vibration that feels like a transmission failure. The problem is specific to Rams equipped with the eTorque mild-hybrid system, often paired with certain V6 or V8 engines.

How to Diagnose

Diagnosing this issue requires a methodical approach, starting with the most obvious symptoms. You will need a basic mechanic's tool set, a code reader capable of reading manufacturer-specific codes, and a safe, well-lit workspace.

Step 1: Check for Diagnostic Trouble Codes (DTCs). Connect your OBD-II scanner. A seized generator will almost certainly trigger multiple codes. Look for codes related to the hybrid battery control module, charging system faults (e.g., P0A78), or communication errors with the generator control module. These codes are your first concrete clue that the problem is within the eTorque system, not the transmission itself.

Step 2: Perform a Visual and Auditory Inspection. With the engine off and cool, open the hood. Inspect the serpentine belt for signs of severe damage, melting, or shredding. A seized generator will destroy the belt. Listen carefully. If you can safely start the engine, a seized unit will produce a loud screeching or grinding noise immediately, if it starts at all. The owner who experienced this said it happened abruptly: "less than 2 hours after buying the truck the e-torque generator seized up on me."

Step 3: Manual Rotation Test (Engine OFF). This is a critical safety check. Ensure the ignition is completely off. Using the appropriate socket on the main engine crankshaft pulley, gently attempt to rotate the engine clockwise. If it will not rotate, or rotates only a tiny amount with great resistance, the belt-driven system is locked. Next, try to manually rotate the eTorque generator pulley using a tool. If it does not spin freely, the generator is seized. Do not force it.

Step 4: Professional System Scan. If you have symptoms like whirring or buzzing but no seizure, the diagnosis becomes more complex. This requires a professional scan tool like a WiTECH or equivalent to monitor the MGU's live data, including voltage output, temperature, and torque-assist status. A dealership or specialized shop can run these diagnostics to confirm a failing generator before it completely fails.

Step-by-Step Fix

Replacing a seized eTorque generator is a significant repair. This guide outlines the general procedure, but due to the complexity, high-voltage safety, and precise calibration required, this is strongly recommended as a professional repair. If you are a highly experienced DIYer, proceed with extreme caution.

Step 1: Safety First - Disable the High-Voltage System. This is non-negotiable. The eTorque system operates at 48 volts. You must locate and disconnect the 12-volt battery first. Then, locate and disconnect the service plug for the 48-volt hybrid battery pack, which is typically in the cabin under the rear seats or in the cargo area. Wait the manufacturer-specified time (usually 10-15 minutes) for the system capacitors to discharge.

Step 2: Remove the Serpentine Belt. You will need a belt tensioner tool to relieve tension on the belt. Due to the likely damage from a seizure, you will probably be removing a broken or severely damaged belt. Document its routing before removal.

Step 3: Disconnect Electrical Connectors. Carefully disconnect the multiple electrical connectors attached to the Motor Generator Unit (MGU). These include the high-voltage connector (usually orange), signal connectors, and any cooling lines if it is liquid-cooled. Label every connector and hose.

Step 4: Unbolt and Remove the MGU. The generator is mounted to the engine block. Support it with one hand and remove the several mounting bolts. The unit is heavy. Carefully maneuver it out of the engine bay. As one owner shared after their repair was complete: "Generator came in and I got my truck back from the shop yesterday 🙏🏻" highlighting the relief after this major component was replaced.

Step 5: Install the New MGU. Carefully position the new, pre-programmed unit. Install and torque the mounting bolts to the factory specification found in the service manual. Do not guess.

Step 6: Reconnect All Electrical and Fluid Lines. Reattach all connectors and cooling lines securely. Double-check every connection.

Step 7: Install a New Serpentine Belt. Route the new belt according to your diagram and use the tensioner tool to slip it onto the final pulley.

Step 8: Re-enable the High-Voltage System. Reconnect the 48-volt service plug, then reconnect the 12-volt battery.

Step 9: Professional Calibration. This is the most crucial DIY limitation. The new MGU must be configured and calibrated using factory-level diagnostic software (WiTECH). This process links the unit to the vehicle's computer, calibrates its position sensor, and clears all fault codes. This step cannot be skipped and requires a visit to a dealer or a shop with the right equipment.

Parts and Tools Needed

• Primary Part: Belt-Driven Hybrid Starter Generator Assembly (MGU). A genuine Mopar part is highly recommended. Part numbers vary by engine (e.g., 3.6L V6 or 5.7L V8 Hemi with eTorque). You must get the correct part for your specific VIN.
• Secondary Part: Serpentine Belt. Always replace with a new belt.
• Tools: Complete socket and wrench set, belt tensioner tool, torque wrench, OBD-II code reader, trim removal tools for accessing the 48V service plug.
• Mandatory Service: Access to a WiTECH or equivalent factory scan tool for module installation and calibration.

Real Owner Costs

The cost to repair this failure varies dramatically between warranty, DIY, and out-of-pocket professional repair.

• Warranty Coverage: For trucks under 8 years/80,000 miles, this repair should be fully covered under the federal emissions warranty for the hybrid system. One owner was quoted a "customer pay estimate of ~$2,041" but successfully argued for warranty coverage, noting "my warranty booklet clearly lists 'Belt Driven Hybrid Starter Generator Assembly' under Parts Covered for 8 years / 80,000 miles." If you're within this mileage and time frame, do not pay out of pocket.
• Out-of-Warranty Professional Repair: The quoted $2,041 is a realistic starting point for just the generator replacement at a dealership. This cost typically includes parts and labor but can climb higher if other components (the belt tensioner, idler pulleys) were damaged during the seizure or if the 48-volt battery also requires testing.
• DIY Cost: The part alone can cost between $1,200 and $1,800 for a genuine Mopar MGU. A new belt is $50-$100. The significant savings are offset by the absolute requirement for a professional calibration, which may cost $150-$300 in labor at a dealership even if you install the part yourself. Total DIY-with-pro-calibration cost: ~$1,400 - $2,200.

Prevention

Proactive maintenance is your best defense against this costly failure, as the eTorque system has limited user-serviceable parts.

1. Adhere to Severe Service Schedules: If you do frequent short trips, tow, or haul, consider more frequent engine air filter changes and oil changes. Clean operation reduces strain on all engine accessories. One conscientious owner planned to get "oil changes every 5k miles and yearly inspections/fluids checked and changed as needed."
2. Listen Attentively: Pay immediate attention to any new whirring, buzzing, or gravelly noises from the engine bay, especially during auto start/stop cycles. Address these sounds immediately; they are the warning before a seizure.
3. Professional System Checks: During routine dealer service, request that they check for any pending or historical fault codes in the hybrid control module. Early detection of voltage or communication irregularities can flag a failing MGU.
4. Belt Inspection: Regularly inspect the serpentine belt for cracks, glazing, or fraying during oil changes. A belt failure can cause secondary damage.

What Owners Say

Real experiences from DODGE owners:

Success Stories

"I put in these Alpharex lights into my 2020 Ram 2500 (Powerwagon) back in July and they’ve been fantastic; up until 2 nights ago. This is my work truck, I use it to plow snow and sling salt and have worked flawlessly up until now… The problem I’m having is that the low and high beam have ceased functioning." — Zakawee (source)

"This is my work truck, I use it to plow snow and sling salt and have worked flawlessly up until now… The problem I’m having is that the low and high beam have ceased functioning." — Zakawee (source)

Owner Experiences

"The Ram I totaled was a 2020 1500 Classic that I bought brand new with 34 miles on it, and it was just under 110k when it was totaled. Amazing truck & I walked away from 2 potentially deadly wrecks unscathed." — rossladd (source)

"In early-ish November I totaled my truck on the way into work by hitting a deer going roughly 70mph lol I was all good thankfully & able to find another (not so) great deal on a truck over that same weekend, but no bullshit less than 2 hours after buying the truck the e-torque generator locked up on me." — rossladd (source)

"Generator came in and I got my truck back from the shop yesterday 🙏🏻 I made a post 16 days ago about totaling my 2020 Ram 1500 Classic due to hitting a deer, and then hours after purchasing my new one the generator seized up on me." — rossladd (source)

Real Repair Costs

"* They are recommending MGU replacement They sent me a customer pay estimate of ~$2,041, but my warranty booklet clearly lists “Belt Driven Hybrid Starter Generator Assembly” under Parts Covered for 8 years / 80,000 miles." — Honest-Fly-9949 (source)

"Especially when I level it and put it on 35s. Anyway, I found a set of OEM rock rails from the 75th AE Power Wagon for $150, and can't for the life of me figure out how they mount." — ZW3903 (source)

"Anyway, I found a set of OEM rock rails from the 75th AE Power Wagon for $150, and can't for the life of me figure out how they mount. I understand the back of the rocker, but where do they go through the pinch weld?" — ZW3903 (source)

FAQ

Q: How long does it take to fix a seized eTorque generator? A: The repair time itself is about 3-5 hours for a skilled technician. However, the total downtime is almost entirely dependent on part availability. The MGU is a specialized component that may not be in stock at local dealerships. Owners have reported waiting weeks for the part to arrive. Once the part is in hand, the actual replacement and calibration can often be completed within a day.

Q: Can I drive my truck if the generator is making noise but hasn't seized? A: It is not recommended. A whirring or buzzing noise indicates internal bearing or electrical failure is imminent. Continuing to drive risks a catastrophic seizure while you're on the road, which will leave you stranded and likely require a tow. Have it diagnosed immediately.

Q: Is this a common issue on the 2020 Dodge Ram? A: Based on owner reports in forums and discussions, failure of the eTorque generator is a known and documented point of failure for this model year, particularly as trucks approach or exceed higher mileage. It is not a universal issue, but it is common enough that there is a specific 8-year/80,000-mile warranty coverage for this component.

Q: DIY vs mechanic - what's recommended for this repair? A: This is overwhelmingly a job for a professional mechanic, preferably at a dealership. The reasons are threefold: 1) High-Voltage Danger: Incorrect handling can cause severe shock or damage. 2) Specialized Tools: The final, critical calibration requires proprietary software. 3) Warranty: If your truck is still under the hybrid component warranty, you must use an authorized facility to keep the coverage valid. DIY is only for experts with access to the calibration tool.

Q: What if my truck is out of the 8-year/80,000-mile warranty? A: You will be responsible for the full cost. It is worth contacting Chrysler Customer Service to discuss the issue, as they may offer a one-time goodwill gesture or partial coverage, especially if you have a full service history at dealerships. Be prepared to pay the full amount, however.

Q: Does this affect all 2020 Rams? A: No. This issue is specific to trucks equipped with the eTorque mild-hybrid system. You can identify if your truck has eTorque by checking your window sticker (it will be listed as an option), looking for an "eTorque" badge on the tailgate, or noting if your truck has a seamless auto start/stop function. Non-eTorque trucks use a conventional alternator and are not subject to this specific failure.