Malfunction Indicator Lamp (MIL) On, Electronic Throttle Control (ETC) Lamp Flashes, Diagnostic Trouble Code (DTC) P2127 Accelerator Pedal Position Circuit Low
full bulletin at NHTSA ↗2021 RAM 1500 cruise control problems
severe Owners of the 2021 RAM 1500 have filed 17 NHTSA complaints about the cruise control at roughly $600 to repair (U.S. federal records, as of August 2026). Source: NHTSA Office of Defects Investigation. See cruise control across all vehicles →
Complaints
17
Recalls
0
Avg fix
$600
| Model year | cruise control complaints |
|---|---|
| 2017 1500 | 28 |
| 2018 1500 | 14 |
| 2019 1500 | 25 |
| 2020 1500 | 6 |
| 2021 1500 (this page) | 17 |
| 2025 1500 | 5 |
2crashes
2injuries
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering cruise control 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.
ERG Hydraulic Tensioner Before replacing any FEAD components, please check FEAD belt layout as per the engine sales code. Customer complaint may include a noise from under the hood described as a squeal, screech, squeak, chirp or belt-related noise and/or noisy tensioner/pulley. Please refer to SOL# S2309000007.
full bulletin at NHTSA ↗Outside Power Fold Rearview Mirror Noise Or Loose At Pivot. Mirror Contacts Door Window Glass In The Folded Position.
full bulletin at NHTSA ↗SPEAKER, 6"x9" Right or Left For a buzz, squeak or rattle (BSR) concern coming from the door speaker area please check that when removing the door trim panel, it doesn't come off with the two-stage push-pin clips (in vehicles that have this type of clip, not the ones with a screw) ONLY with its outer clip. If found to have any clip coming with both inner and outer part, please replace the clips with new ones (as old ones might have already been deformed) and reinstall the door trim. Follow Service Library procedure to properly remove/install the door trim. For this issue send feedback via email to FCA Redacted Content. If no response in 15 minutes, proceed with repair. Contact Us for feedbac
full bulletin at NHTSA ↗LATCH Front Door,LATCH, Rear door, Front Door 2022 to 2024 RAM (DT) Inside door lock rod binding. If customer comes in with the issue described, please adjust interior trim panel and rod to verify proper assembly and check if the issue goes away before replacing the latch. Please contact FCA Redacted Content. If no response in 15 minutes, proceed with repair.
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 describe engine shutdowns without warning at highway speeds, forcing emergency stops on shoulders. Some report the truck shut off with no warning lights beforehand; dealers test-drove over 700 miles and could not duplicate the failure. Others detail fuel-related codes stored after multiple stalls that put lives at risk.
Unintended acceleration shows up repeatedly. One owner depressed the brake at 2–3 mph in a drive-thru and the truck accelerated harder the more he braked, crashing into the car ahead and causing back injury. Another felt the accelerator stick while merging, wouldn't slow with brakes, and had to unstick the pedal by foot.
Adaptive cruise control behaves dangerously: trucks accelerate aggressively toward stationary traffic when a preceding vehicle moves away, even with stopped vehicles 2 car lengths ahead. Drivers report having to slam brakes repeatedly to avoid collisions.
ABS and electronic stability control failures appear in multiple narratives, with "service electronic braking system" warnings, replaced tire sensors and brake master cylinder sensors under warranty, and an ABS module finally unavailable from the manufacturer due to vendor supply issues. One owner's vehicle is unsafe to drive with no ABS or traction control.
Forward collision warnings flash but the truck fails to apply brakes automatically. Engine surging episodes last 10 minutes with RPMs stuck between 5–7k despite foot off the pedal. Dealerships report unfamiliarity with these issues or inability to diagnose and repair them.
Same RAM 1500 cruise control reports on nearby years: 2018 · 2019
Failure modes owners describe
Engine stall and power loss during driving
Engine shuts down without warning while vehicle is in motion, with no warning lights on dash beforehand. Vehicle loses all power, forcing driver to coast to safe location. Can occur multiple times over months.
When: Various speeds (55 mph highway, 60 mph express lane, low-speed driving). First incident reported at 21 miles, others at 8,600 miles and beyond.
Symptoms owners cite: Sudden engine shutdown while driving; No warning lights before shutdown; Loss of power steering and braking assist; Vehicle coasts to emergency lane or shoulder; Difficulty restarting; may require pumping throttle to keep running
Codes mentioned: Fuel-related codes (3 codes stored per one narrative), Service electronic throttle control warning
Repairs/costs cited: Dealership unable to duplicate issue or identify root cause after 700+ test miles. One owner reports fuel injector failure.
Recalls/TSBs owners mention: Chrysler STAR technical advisors instructed dealership to replace parts without proper diagnosis. No recall issued for this specific failure pattern.
Unintended acceleration while braking
Vehicle accelerates when brake pedal is depressed. Severity increases with brake pedal pressure—harder braking causes harder acceleration. Occurs at low speed (2-3 mph) in drive-thru and in park. Also occurs at highway speeds with sudden acceleration spikes.
When: Low speed (2-3 mph) and highway driving. One incident at 8,600 miles. Another at 39 mph on off-ramp.
Symptoms owners cite: Vehicle accelerates harder as brake pedal is pressed harder; Sudden acceleration without pedal input; Throttle pedal stuck in accelerated position (felt sticky, spring-like); Speed jumps rapidly (0 to 55 mph in seconds); Brakes do not slow vehicle during acceleration event
Repairs/costs cited: One owner sustained back injuries from crash into vehicle ahead during drive-thru. Accelerator pedal unstuck manually with shoe. Dealership kept vehicle but did not repair.
Adaptive cruise control aggressive acceleration and braking failures
Adaptive cruise control system behaves erratically when vehicles enter and exit detection zone. After car pulls away from ahead, truck accelerates hard toward previously vacated space or stationary traffic. System also fails to slow vehicle appropriately when car ahead moves.
When: Highway driving at cruise control speeds (60 mph, approaching traffic lights)
Symptoms owners cite: Truck accelerates aggressively when preceding vehicle moves away; Hard acceleration toward stationary or stopped traffic; Inadequate slowing when vehicle ahead is detected; Driver must slam brakes to avoid collision; System appears to attempt returning to initial set speed without checking for obstacles
Electronic stability control and ABS system failure
ABS module fails, disabling electronic stability control and traction control. Dashboard displays 'service electronic braking system' warnings. Related to tire sensor and brake master cylinder sensor issues. One owner notes Stellantis recall for 2019-2024 Ram 1500 due to ABS module software flaw.
When: Early ownership and ongoing. One complaint at 31,500 miles.
Symptoms owners cite: Service electronic braking system warning on dash; Service braking system warning and check engine light; Loss of ABS and traction control functionality; Vehicle stuck in park mode; brakes will not disengage; ABS module under engineering review; unavailable part
Codes mentioned: ABS module fault, Tire sensor fault, Brake master cylinder sensor fault
Repairs/costs cited: Tire sensor replaced under extended warranty. Brake master cylinder sensor replaced under warranty. ABS module unavailable due to lack of vendor supply with no resolution timeline. Vehicle unsafe to drive.
Recalls/TSBs owners mention: Stellantis issued recall for 2019-2024 Ram 1500 due to ABS module software flaw disabling ESC. RAM customer care confirmed ABS module part unavailable and anticipated delays due to vendor supply issues.
Automatic emergency braking system failure
Forward collision warning system detects hazard and flashes brake warning, but truck fails to apply brakes automatically. System provides alert only; does not prevent collision.
When: Multiple occasions during driving
Symptoms owners cite: Brake warning light flashes on dash; No brake application despite warning; Driver must manually slam brakes to avoid collision; System fails on several occasions
Engine surge and uncontrolled rev condition
Engine RPMs increase and remain elevated regardless of driver input. RPMs stay between 5-7k even in neutral with foot off pedal and at stops. Engine continues revving despite attempt to slow or stop vehicle. Occurs independently of cruise control status.
When: 3-month period with at least 2 incidents (10/18/2024 reported). Duration 10+ minutes per event.
Symptoms owners cite: RPMs slowly increase without pedal input; Engine continues revving in neutral with foot off gas; Elevated RPMs (5-7k range) maintained at stops; Difficulty maintaining speed control; Hard to slow down; brake must be pressed to ground to stop; Engine audibly surging and accelerating
Repairs/costs cited: Dealership reports unfamiliarity with issue. Resolved only by stopping and turning off engine.
Throttle error and limp mode
Vehicle experiences throttle error, will not respond to pedal input, and goes into limp mode. Vehicle shuts down or severely restricts power output. Speed limited to 30 mph or less after restart.
When: 55 mph highway driving. Occurred within first year of ownership.
Symptoms owners cite: Throttle error code triggered; Engine shuts down or enters limp mode; Vehicle will not accelerate or responds minimally; Speed severely limited after restart (30 mph max); Risk of rear-end collision from following traffic
Codes mentioned: Throttle error code
Repairs/costs cited: Nearly caused accident from rear-end collision due to reduced speed capability.
Vehicle immobilization in park mode with brake disengagement failure
Vehicle becomes stuck in park mode because brakes will not disengage. Brakes remain locked despite being released by driver. Temporary fix requires restarting vehicle.
When: September 3, 2024 and weeks prior to that date
Symptoms owners cite: Cannot shift out of park; Brakes remain disengaged and locked; Brake pedal has no effect on system
Repairs/costs cited: Restart vehicle to temporarily resolve, but issue persists.
Synthesized from 17 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 0 most recent
Had cruise control 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 cruise control problem on the 2021 RAM 1500?
It's a meaningful issue. 17 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $600.
At what mileage does the cruise control typically fail?
Based on the 17 complaints filed, cruise control issues most often appear around 86,090 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
What does it cost to fix?
Independent shops typically charge around $600 for cruise control 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 cruise control?
No active recalls currently cover cruise control 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.