The 2021 Ram 2500 is a solid heavy-duty platform, but the 6.7L Cummins suffers from CP4 fuel pump failures that grenade the entire fuel system, and both engines show premature transmission cooler and wiring harness issues that can strand you.
CP4 Fuel Pump Catastrophic Failure (6.7L Cummins)
Occasional · high severity
Typical onset: 40,000-90,000 mi
Symptoms: Sudden loss of power and immediate stalling with no restart, Metal contamination throughout entire fuel system from pump internals disintegrating, Often zero warning — truck runs fine then dies within seconds
Fix: Complete fuel system replacement: CP4 pump, injectors, fuel rails, lines, tank cleaning, sometimes turbo if metal traveled upstream. 20-30 hours labor. This is the nightmare scenario for Cummins owners — pump grenades and sends metal shrapnel through every fuel component.
Estimated cost: $8,000-15,000
Transmission Oil Cooler Internal Failure
Common · high severity
Typical onset: 50,000-100,000 mi
Symptoms: Coolant mixing with transmission fluid — strawberry milkshake appearance in trans pan or radiator, Transmission slipping or delayed engagement after cooler breach, Overheating transmission or engine temp spikes
Fix: Replace radiator assembly with integrated trans cooler, flush transmission multiple times, often requires new torque converter if contamination severe. 8-12 hours labor. Common enough that many owners install aftermarket external coolers as preventive measure.
Estimated cost: $2,200-4,500
Wiring Harness Chafing and Relay Failures
Common · medium severity
Symptoms: Intermittent no-start conditions — starter relay clicking or dead, Random electrical gremlins: gauges flickering, stabilitrak warnings, trailer brake controller dropout, Harness rubbing on frame rails near steering box or transmission crossmember
Fix: Inspect harness routing behind headlight assemblies and along frame — reroute and wrap affected sections, replace failed relays in TIPM (Totally Integrated Power Module). 2-4 hours labor depending on extent. Multiple NHTSA recalls address this but don't catch all failure modes.
Estimated cost: $400-1,200
Transmission Mount Separation
Common · medium severity
Typical onset: 60,000-110,000 mi
Symptoms: Clunk or bang when shifting from park to drive or reverse, Vibration through cab at idle in gear, Visible rubber mount tearing or complete separation from crossmember
Fix: Replace transmission mount — straightforward job but requires trans support. 1.5-2 hours labor. OEM mounts fail faster on diesels due to extra torque; aftermarket polyurethane options last longer but transmit more NVH.
Estimated cost: $250-450
6.4L Hemi Valve Seat Recession and Piston Failure
Occasional · high severity
Typical onset: 80,000-140,000 mi
Symptoms: Misfires on one or more cylinders — often cylinder 7 or 8, Metal debris in oil from dropped valve seats or cracked piston skirts, Loss of compression, rough idle, check engine light with multiple misfire codes
Fix: Valve seat drop requires cylinder head rebuild or replacement; piston failure means full shortblock or engine replacement. Head work alone: 12-16 hours; shortblock swap: 25-35 hours. This is the 6.4's Achilles heel — less common than CP4 failure but equally devastating when it hits.
Estimated cost: $5,500-12,000
Tailgate Hinge Detachment
Occasional · low severity
Symptoms: Tailgate sagging or misaligned when closed, Popping or cracking sound from hinge mounts, Complete hinge separation — tailgate drops when opened (covered by recall)
Fix: Hinge reinforcement brackets installed per NHTSA recall campaign, or full hinge replacement if brackets already failed. 1-2 hours labor. Check if recall was performed; if not, get it done free at dealer.
Estimated cost: $0-400
Owner tips
If buying a 6.7L Cummins, install a CP3 fuel pump conversion kit immediately — $3,000-4,000 spent upfront beats $15K in catastrophic failure repairs
Add an aftermarket transmission cooler before towing heavy — the factory integrated cooler is marginal at best under sustained load
Inspect wiring harness routing every oil change — zip-tie away from frame and sharp edges, especially behind headlights
6.4L Hemi owners: avoid sustained high-RPM towing and monitor oil consumption closely after 60K miles — early warning of valve/piston issues
Cummins version is a beast if you survive the CP4 pump lottery or convert it immediately; 6.4L Hemi is cheaper upfront but grenades engines more often — buy extended warranty or budget $10K for eventual engine work.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.
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Chrysler (FCA US, LLC) is recalling certain 2021-2022 Ram 1500, Ram 2500, Ram 3500, Ram 4500, and Ram 5500 vehicles. The steering column control module may cause the driver's side air bag not to deploy as intended. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 208, "Occupant Crash Protection."
Consequence: A driver's side air bag that does not deploy as intended increases the risk of injury in a crash.
Remedy: Dealers will replace the steering column control module, free of charge. Owner notification letters were mailed beginning December 11, 2025. Owners may contact Chrysler customer service at 800-853-1403. Chrysler's number for this recall is 14C. Vehicle Identification Numbers (VINs) involved in this recall became searchable on NHTSA.gov beginning November 13, 2025.
Chrysler (FCA US, LLC) is recalling certain 2021-2023 Ram 2500, 3500, 3500 Cab Chassis, and 4500, 5500 Cab Chassis vehicles equipped with a Cummins 6.7L Turbo Diesel engine. An electrical short may occur in the heater grid relay with the ignition on or off.
Consequence: An electrical short in the relay can result in an engine compartment fire with the ignition on or off, increasing the risk of injury.
Remedy: Owners are advised to park outside and away from structures until the recall repair is complete. Dealers will replace the relay, free of charge. This will be a Phased campaign. Phase 1 will include 2023 model year vehicles. FCA US will notify dealers on or about 3/23/2023 and begin notifying owners on or about 4/5/2023. Phase 2 will include 2022 model year vehicles and Phase 3 will include 2021 model year vehicles. FCA US will notify dealers and owners on or about 4/27/2023 for Phase 2 and 5/11/2023 for Phase 3. Interim owner notification letters informing owners of the safety risk were mailed March 28, 2023. Owner notification letters are expected to be mailed April 5, 2023. Owners may contact FCA US, LLC customer service at 1-800-853-1403. FCA US, LLC's number for this recall is 13A. This recall is an expansion of and supersedes recall number 21V-798.
STRUCTURE:BODY:TAILGATE:HINGE AND ATTACHMENTS · 22V904000
2022-12-08
Chrysler (FCA US, LLC) is recalling certain 2019-2022 Ram 1500, 2500, and 3500 pickup trucks. The tailgate may not latch properly due to misaligned tailgate strikers, which could result in the tailgate opening while driving.
Consequence: An unintended tailgate opening while driving may result in a loss of unsecured cargo, possibly creating a road hazard and increasing the risk of a crash.
Remedy: Dealers will inspect the tailgate striker alignment to the box latch and adjust, if necessary, free of charge. Owner notification letters were mailed December 22, 2022. Owners may contact FCA US, LLC customer service at 1-800-853-1403. FCA US, LLC's number for this recall is ZB8.
POWER TRAIN:AUTOMATIC TRANSMISSION · 22V835000
2022-11-10
FCA US, LLC (Chrysler) is recalling certain 2020-2023 Ram 2500 and 2020-2022 Ram 3500 vehicles. A build-up of pressure and heat inside the transmission may result in a transmission fluid leak from the dipstick tube.
Consequence: Leaking transmission fluid may contact an ignition source within the engine compartment, increasing the risk of a fire.
Remedy: Dealers will replace the transmission dipstick and transmission vent assembly, free of charge. Owner notification letters were mailed December 29, 2022. Owners may contact FCA US, LLC customer service at 1-800-853-1403. Chrysler's number for this recall is ZA3.
SERVICE BRAKES, HYDRAULIC:ANTILOCK/TRACTION CONTROL/ELECTRONIC LIMITED SLIP:CONTROL UNIT/MODULE · 22V140000
2022-03-10
Chrysler (FCA US, LLC) is recalling certain 2019-2022 Ram 2500 and 2021-2022 Dodge Durango vehicles, and 2019-2022 3500 cab chassis with GVWR less than 10,000 lbs. The ABS control module software may prevent the electronic stability control (ESC) malfunction indicator light from illuminating during certain conditions. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 126, "Electronic Stability Control Systems."
Consequence: An ESC malfunction indicator light that fails to illuminate during an electronic stability control problem can increase the risk of a crash.
Remedy: Dealers will update the ABS control module software, free of charge. Owner notification letters were mailed March 29, 2022. Owners may contact FCA US, LLC customer service at 1-800-853-1403. FCA US, LLC's number for this recall is Z20.
AIR BAGS:SIDE/WINDOW:CURTAIN · 21V925000
2021-11-24
Chrysler (FCA US, LLC) is recalling certain 2021-2022 Ram 2500, Ram 3500, and 2021 Ram 1500 Classic pickup trucks. The side air bag inflatable curtain (SABIC) assemblies may have been manufactured with the incorrect amount of compressed gas, which can result in an improper air bag deployment.
Consequence: An air bag that deploys improperly can increase the risk of injury in a crash.
Remedy: Dealers will replace the SABIC assemblies, free of charge. Owner notification letters were mailed January 17, 2022. Owners may contact FCA US, LLC customer service at 1-800-853-1403. FCA US, LLC's number for this recall is Y99.
Chrysler (FCA US, LLC) is recalling certain 2021-2022 Ram 3500, 2500 pickup trucks, and Ram 3500, 4500, and 5500 cab chassis vehicles equipped with Cummins 6.7L Turbo Diesel engines. An electrical short in the relay may cause a vehicle fire with the ignition on or off.
Consequence: A vehicle fire increases the risk of injury.
Remedy: Owners are advised to park these vehicles outside of buildings or structures, and not near other vehicles, until the vehicle has been remedied. Dealers will inspect and, if needed, replace the Solid State Intake Heater Grid Relay ("Relay"); if FCA US Recall ID Y08 (NHTSA Recall ID 21V-163) is open, then insulating material will be applied to the Relay after inspection. Owner notification letters were mailed November 10, 2021. Owners may contact FCA US, LLC customer service at 1-800-853-1403. FCA US, LLC's number for this recall is Y76. This recall has been superseded by 23V060.
ELECTRICAL SYSTEM · 21V163000
2021-03-11
Chrysler (FCA US, LLC) is recalling certain 2021 Ram 2500, 3500, and 3500, 4500, and 5500 Cab Chassis vehicles equipped with a Cummins 6.7L Turbo Diesel engine. An electrical short may occur in the Solid State Intake Heater Grid Relay, which could result in a vehicle fire.
Consequence: A vehicle fire increases the risk of injury.
Remedy: Dealers will inspect and, if needed, replace the Solid State Intake Heater Grid Relay ("Relay"); if FCA US Recall ID Y08 (NHTSA Recall ID 21V-163) is open, then insulating material will be applied to the Relay after inspection. Customers are advised to not park these vehicles inside of buildings or structures, or near other vehicles until the vehicle has the final repair completed. Owner notification letters were mailed November 10, 2021. Owners may contact FCA US, LLC customer service at 1-800-853-1403. FCA US, LLC's number for this recall is Y76. Owners may contact FCA US LLC customer service at 1-800-853-1403. FCA US LLC's number for this recall is Y08. This recall has been superseded by recall number 21V-798.
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