Flash: Transmission Control Module (TCM) Updates Customers may comment on one or more of the following: SYMPTOM: ● **Harsh or slipping feeling during upshifts (1st - 5th). ● Harsh or slipping feeling during kickdown events under throttle. ● Transmission fluid odor (burnt smell).** ● During a 2 - 3 transmission upshift, the engine is hitting rev limit. ● Hesitation feel during a pedal tip in, while engine is warming up below 1 °C (30 °F) ambient temp. This bulletin involves reprogramming the TCM with the latest available software.
full bulletin at NHTSA ↗2021 RAM 1500 powertrain problems
moderate Owners of the 2021 RAM 1500 have filed 91 NHTSA complaints about the powertrain, typically surfacing around 31,000 miles at roughly $2,500 to repair (U.S. federal records, as of July 2026). Source: NHTSA Office of Defects Investigation. See powertrain across all vehicles →
Failure mileage
Complaints
91
Recalls
0
Avg fix
$2,500
| Model year | powertrain complaints |
|---|---|
| 2017 1500 | 81 |
| 2018 1500 | 50 |
| 2019 1500 | 183 |
| 2020 1500 | 59 |
| 2021 1500 (this page) | 91 |
| 2024 1500 | 13 |
| 2025 1500 | 38 |
1injury
What stands out
Owners have filed 91 powertrain complaints with NHTSA against this vehicle, but no formal recall covers the issue — the federal record reflects what manufacturers have admitted, not everything owners are reporting.
No new NHTSA powertrain complaint has been filed on this vehicle in over 4 years — the issue may be aging out of the active population.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering powertrain on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
The vehicle will exhibit a service transmission/check engine warning indicator for the following transmission models: 845RE, 8HP45, 850RE, 8HP50, 8HP70, 8HP75, 8HP75-PHEV, 8HP75-LCV, 8HP90, 8HP95. Transmissions may exhibit the following diagnostic codes: P07E4, P1DB2, P0716, P1B14, P0733, P1D90, P1DB7, P1B13.
full bulletin at NHTSA ↗Service transmission/check engine warning indicator for the 850RE, 8HP50, 8HP70, 8HP75, 8HP75-PHEV transmissions that have fault codes P07E4, P1DB2, P0716, P1B14, P0733, P1D90, P1DB7, P1B13.
full bulletin at NHTSA ↗Rear Axle Vibration Shudder Or Chatter Customers may experience the following: ● A chatter, shudder, or vibration from the rear axle during turns. NOTE: This may happen more as the vehicle ages, especially if the vehicle is used extensively for towing or hauling heavy loads. The cause of the concern may be due to degradation of the rear axle fluid. It is very important to follow the routine maintenance schedules on these vehicles when it comes to changing the rear axle fluid if the vehicle is used primarily for towing or hauling heavy loads. If you experience a vehicle with the above condition, please perform the proper maintenance procedures for the rear axle and replace the fluid first bef
full bulletin at NHTSA ↗To inform dealers about the 850RE valve body PN: R8348504A connector: the original 16-pin connector included six pins that were not used in this application. To simplify the design, the connector has been optimized and updated to a 10-pin configuration.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Owners of 2021 Ram 1500s report recurring powertrain issues creating genuine hazards. The most common: stalling without warning during normal driving—at turns, traffic merges, or highway speeds—followed by automatic shifting to park and parking brake engagement. Owners describe losing all motive power mid-intersection or mid-lane, having to restart while stranded. Dealers consistently fail to reproduce the problem or find diagnostic codes, though some cases involve the powertrain control module, motor generator unit (eTorque/hybrid system), or transmission components.
Transmission problems include stuck gears (refusing to upshift from first, locking in third), harsh lurching on shifts, and slipping. Several owners report "4WD Overheated" warnings and unexpected 4WD engagement while driving. Loss of engine power under acceleration or while towing is documented, along with electronic throttle control faults. Exhaust manifold cracks occur with minimal warning—owners report tapping on cold starts, then sudden failure. Motor generator unit failures produce grinding noises and force extended downtime due to parts backorders. A smaller group reports unintended acceleration, erratic dashboard displays triggering on their own, and fuel system concerns tied to recall campaigns. Engine shutoffs under mild braking, cold starts, or simple turns form a distinct pattern. Nearly all service attempts yield "no codes found" or "cannot reproduce," frustrating owners trying to establish a safety record before failures escalate.
Same RAM 1500 powertrain reports on nearby years: 2018 · 2019 · 2020 · 2024
Failure modes owners describe
Unexpected stalling with automatic park shift and e-brake engagement
Engine dies without warning while driving, typically at low speed or during turns. Vehicle automatically shifts to park and engages emergency brake. Restart restores function but failure recurs randomly.
When: 0-85,000 miles; frequently within first 6 months and early in ownership
Symptoms owners cite: Engine shuts off with no warning lights; Vehicle shifts to park on its own; Electronic parking brake engages automatically; Dash displays message to shift to park and release brake; Multiple occurrences over weeks or months
Codes mentioned: U0402 (Invalid Data Received From TCM), P1C64-00 (Hybrid perf. Engine speed below target during autostart)
Repairs/costs cited: Dealers report inability to reproduce or find codes; some replace powertrain control module, motor generator unit, or eTorque system; parts often on backorder
Recalls/TSBs owners mention: NHTSA Campaign 23V265000 (Powertrain); VIN inclusion varies; repairs sometimes performed but failures recur; delayed parts availability mentioned in multiple complaints
Transmission gear-lock and improper shifting
Transmission fails to upshift out of first or third gear, or unexpectedly shifts into park while driving. Grinding, lurching, and slipping reported. Vehicle may require restart to reset.
When: 19,000-140,000 miles; some owners report issue within months of purchase
Symptoms owners cite: Vehicle stuck in first or third gear, high RPMs for low speed; Harsh lurching on acceleration; Transmission slips between shifts; Sudden downshift with burning smell through vents; Vehicle unable to engage reverse without restart
Codes mentioned: Transmission Temperature Warning Light, Electronic Throttle Control Warning Light
Repairs/costs cited: Dealers cite premature 4th gear failure and recommend transmission replacement; repair wait times 3-4 months; multiple complaints of dealers claiming issue 'becoming common' with 2021 Ram V6 and Dodge vans
Recalls/TSBs owners mention: Dodge opened cases; Mopar involvement; extended warranty coverage mentioned; parts backlogs creating multi-month delays
Motor Generator Unit (eTorque) failure and whining noise
MGU bearing fails, producing loud whining or grinding noise from engine compartment. Unit requires replacement but parts are chronically on backorder. Vehicle may stall or lose power during operation.
When: Under 50,000 miles; deteriorates over weeks to months
Symptoms owners cite: Loud whining or grinding noise from engine compartment; Intermittent hesitation during acceleration; Vehicle may surge then hesitate when accelerating; Stalling during towing or light acceleration; Battery Saver alert before complete failure
Codes mentioned: Alternator light / Battery Saver activation warning
Repairs/costs cited: Dealer diagnosis confirms MGU bearing failure; replacement on backorder with no ETA; dealers advise continuing to drive unit until it fails; owners report 2+ month waits with no loaner vehicle offered
Recalls/TSBs owners mention: Parts on backorder; no recall issued; warranty covers replacement but delayed by supply chain; one owner notes lack of TSB or bulletin despite multiple reports
Exhaust manifold cracking
Left and/or right exhaust manifold cracks without warning. Initially detected by tapping noise on cold start, then manifold splits. Multiple owners report both manifolds failing within months of each other.
When: 51,000-54,000 miles; cold starts trigger tapping sound before failure
Symptoms owners cite: Tapping noise during cold start; Manifold cracks audibly 'down whole manifold'; Exhaust fume odor inside cabin via HVAC; Potential carbon monoxide exposure when idling with windows closed
Repairs/costs cited: Manifold replacement performed under powertrain warranty (60,000 mile coverage); independent inspection confirmed improper installation or flawed sealing from prior repairs; one owner reports both manifolds replaced, concerned about recurring failures after warranty expires
Recalls/TSBs owners mention: Repairs covered under 60,000 mile powertrain warranty; RAM case management opened (case #92878431); poor communication on permanent fix; owners request recall with permanent solution
Unintended acceleration and loss of throttle response
Vehicle accelerates on its own without driver input; brake application required to slow it. After restart, issue recurs within days. Alternatively, pedal input produces no acceleration response.
When: Low mileage; occurs suddenly and recurs over several days
Symptoms owners cite: Truck accelerates without accelerator pedal depression; Cruise control not active but vehicle surges forward; Dinging sound and all dash lights illuminate during event; Brakes slow the vehicle but acceleration resumes when brakes released; Issue temporary after restart but returns within days
Codes mentioned: All warning lights and service lights illuminate during event
Repairs/costs cited: One owner reports Safford Dodge diagnosed failed accelerator pedal connection; pedal replaced and issue resolved; another reports dealer found 'failed connection for acceleration pedal'
Recalls/TSBs owners mention: Repair performed at dealership after confirmation of issue
4WD system unexpected engagement and control loss
Vehicle spontaneously shifts into 4WD High/Low while driving at low speed, locks parking brake, and loses responsiveness to driver input. System may not release 4WD mode for extended period.
When: Occurs during normal driving; two incidents while backing out of driveway, one at 20 mph on road, pattern of recurrence unclear
Symptoms owners cite: Vehicle jumps from 2WD to 4WD High and Low simultaneously; Parking brake locks automatically without driver input; Vehicle loses traction in snow/light conditions with error 'Overheated Performance Temporarily Reduced'; Rear end fishtails in slippery conditions; System will not release 4WD mode after initial incident
Codes mentioned: 4WD Overheated Performance Temporarily Reduced
Repairs/costs cited: Dealers replaced differential and transfer case fluid to attempt fix; unable to reproduce issue on second visit; vehicle unable to move in minimal snow after this failure; multiple towing incidents required
Recalls/TSBs owners mention: No clear manufacturer response in narratives; dealers cite inability to reproduce; owners suspect transfer case motor or light-duty transfer case as source
Engine and electronic throttle control faults with power loss
Check engine light illuminates; vehicle loses power or acceleration responsiveness. Electronic throttle control warning appears; some instances include rapid battery drain. Multiple restart cycles may be required.
When: Various mileage; some at 31,000 miles with recall campaign 22V767000 (HPFP); others at 37,000-75,000
Symptoms owners cite: Check engine light comes on without warning; Loss of acceleration or power at highway speed; Electronic Throttle Control warning light; Vehicle slows suddenly from normal highway speed to 35 mph; Rapid battery voltage drop (full charge to dead within 5 minutes); Vehicle requires manual restart after coasting to stop; Loss of all electrical and powertrain function
Codes mentioned: P020E (fuel system related), P00AF-00 (Turbocharger Boost Control Module 'A' Performance), C121C-00 (Torque Request Signal Denied), Electronic Stability Control warning, Service Electronic Throttle Control
Repairs/costs cited: Dealers cleared codes but same issues recurred; HPFP recall (Z96, 22V767000) involved but parts initially unavailable; one owner reports alternator inverter failure causing battery drain and electrical shutdown; software updates attempted; owners report continuing issues after dealer service
Recalls/TSBs owners mention: NHTSA Campaign 22V767000 (HPFP); 24V65300 (software related); parts unavailable at time of service; dealers declined service when check engine light was off; extended warranty (MOPAR) involved in some cases
Transmission fluid leak and transfer case damage
After transmission repair, vehicle leaks transmission fluid from a hole in the transfer case. Transfer case damage goes undetected during routine maintenance and only appears after transmission service.
When: 28,000 miles; discovered during transmission replacement service
Symptoms owners cite: Power loss while driving at 35 mph; Check engine light illuminated; Transmission fluid leak from transfer case hole; Vehicle begins losing power
Codes mentioned: NHTSA Campaign 24V754000 (Visibility) notice received before failure
Repairs/costs cited: Transmission and clutch pack replaced; leak from transfer case discovered post-repair; transfer case damage not detected during regular maintenance; repair not covered under warranty per dealer statement
Recalls/TSBs owners mention: NHTSA Campaign 24V754000 referenced; warranty denial for transfer case repair
System electrical instability and ghost-touch screen behavior post-recall
After ABS module recall service, vehicle develops cascading electrical and mechanical failures affecting multiple systems. Dash lights flicker erratically; HVAC and other systems change settings on their own; vehicle enters park unexpectedly.
When: Post-recall service (May 21, 2025); failures escalate over following weeks
Symptoms owners cite: All cluster lights flash upon startup; Dashboard ghost-touch behavior with erratic indicator lighting; Vehicle shifts into park while driving at low speed (7 mph); Parking brake engages while vehicle in motion; HVAC temperature settings change independently (e.g., jump to 72°F); Parasitic battery draw; Fuel range readings drop suddenly (180 miles to 23 miles instantly); Electronic Stability Control coordination loss
Codes mentioned: General system instability across CAN network post-recall
Repairs/costs cited: Dealership acknowledges ABS module recall performed; refuses comprehensive inspection until July 8 despite escalating safety concerns; owner suspects CAN network communication failure triggered by update
Recalls/TSBs owners mention: ABS module recall (recall date May 21, 2025); dealership declined loaner vehicle citing purchase location; no resolution provided as of complaint date
Fuel system issues and stalling related to recall
Check engine light and fault codes related to fuel system and HPFP trigger recall campaign notification. Vehicle stalls after restart or loses power. Repeated stalling even after fuel pump replacement and engine/transmission replacement.
When: Various mileage; initial issue around 800-1000 miles; recurring after repair at 2024
Symptoms owners cite: Check engine light illuminates without warning; Vehicle stalls while crossing busy intersection or at low speed; No warning lights before first incident; Stalling recurs after fuel pump replacement and full powertrain replacement
Codes mentioned: P020E or related fuel system codes, Recall 22V767000 (HPFP), Additional recalls received (fuel pump and two others) after first repair failed
Repairs/costs cited: Dealership replaced fuel pump after 7-month ownership; later performed complete powertrain, transmission, and engine replacement; vehicle stalled again in 2024 while crossing intersection; second recall notice received indicating first repair inadequate
Recalls/TSBs owners mention: Recall 22V767000 issued; multiple recalls received post-repair indicating manufacturer awareness but inadequate initial fix; owner notes class action lawsuits filed related to this issue
Cold start stalling and e-Torque system malfunction
Engine dies during cold starts or after extended idle periods, dropping RPM below 500 and losing throttle response. Automatic shift to park and e-brake engagement follow. Issue reproducible in cold conditions; e-Torque system replacement required but stalling recurs.
When: 5,000 miles reported in one case; occurs reliably on cold starts and extended idle
Symptoms owners cite: Engine stalls during cold start or after long idle; RPM drops below 500 with no throttle feedback; Vehicle shifts to park and engages e-brake; Restart restores function but issue repeats with cold start; Issue reproducible every cold start cycle; Stalling resumed after eTorque system replacement and during towing
Codes mentioned: P1C64-00 (Hybrid perf. Engine speed below target during autostart)
Repairs/costs cited: Dealer diagnosed and replaced eTorque system; issue persisted after repair; stalled again while towing; owner has video evidence of repeated failures
Recalls/TSBs owners mention: eTorque system replacement performed; warranty repair attempted but issue unresolved
Power distribution module relay and fuse seating failure
Multiple relays and fuses in the power distribution module are not fully seated in their sockets. Owner discovered 75% of fuses improperly seated, with relays physically tilted. This intermittent connection causes system failures and engine stalling.
When: Low mileage; discovered during investigation of stalling incident
Symptoms owners cite: Engine dies during low-speed turn (5 mph); Vehicle enters park and activates e-brake automatically; Power distribution module relays not fully seated
Repairs/costs cited: Owner manually reseated all relays and fuses; owner notes numerous online reports of same failure; discovering this requires under-hood inspection
Recalls/TSBs owners mention: Vehicle pending recall for backup camera; power distribution issue not addressed by dealership before discovery of relay seating
Synthesized from 91 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 3 most recent
Unknown Failure causing issue. Vehicle's Engine Shutoff while traveling down the road with no warning messages. Then message says to apply breaks and push "start", but it was in the "Run" and still coasting in Drive on the road. After it slowed to about 5-10 mph, the emergency break system engaged and the vehicle went to "Park" causing the vehicle to throw me forward in the seat and objects were…
My bearings in my rear assembly has failed before 100K miles. In addition, I had to replace the eTorque generator before 100K miles.
After coming to a complete stop where the auto stop engages and then trying to start and move again, the truck will stall, put itself into park and apply the emergency brake. The only way to resolve from here is to turn off/on the truck and release the parking brake. A big hazard when in heavy truck and people are expecting the truck to be moving.
Had powertrain trouble with your 2021 RAM 1500?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the powertrain problem on the 2021 RAM 1500?
It's a documented issue but not catastrophic. 91 complaints have been filed. Repairs average $2,500 and most owners catch it before it causes a breakdown.
At what mileage does the powertrain typically fail?
Across the 15 complaints that reported odometer mileage, most powertrain failures cluster between 16,000 and 60,000 miles, with the median around 31,000. A quarter of owners report trouble before 16,000; a quarter make it past 60,000. Maintenance history matters more than the odometer alone — this is the reported failure window, not a guarantee.
What does it cost to fix?
Independent shops typically charge around $2,500 for powertrain repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to powertrain?
No active recalls currently cover powertrain issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2021/RAM/1500.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.