What Does P0121 Mean on a 2024 Ram 2500?
A P0121 code on your 2024 Ram 2500 signals that the PCM has detected an abnormal TPS voltage pattern. On a new heavy-duty truck, this is uncommon and should be addressed under warranty immediately.
The 2024 Ram 2500 offers the 6.4L Hemi V8 (port injection) or the 6.7L Cummins turbo-diesel. At low mileage, software calibration is the primary suspect.
Top Causes of P0121 on the 2024 Ram 2500
- PCM software calibration – New model year updates. Likelihood: 40%
- Factory throttle body defect – Manufacturing issue. Likelihood: 25%
- Connector assembly issue – Not properly seated. Likelihood: 20%
- Heavy-duty vibration – HD truck vibration can loosen connections. Likelihood: 10%
- Carbon buildup – Unlikely at low mileage. Likelihood: 5%
Symptoms You May Notice
- Check Engine Light on
- Inconsistent idle
- Hesitation during acceleration
- Reduced towing confidence
- Cruise control issues
How Serious Is This Code?
P0121 is medium severity. Your 2024 Ram 2500 remains drivable. Schedule a dealer visit soon—within the week. Full warranty applies.
Diagnostic Steps
- Take the truck to your Ram dealer—warranty covers this
- Dealer uses wiTECH for diagnostics
- Check for software updates
- Inspect throttle body and connector
- Monitor live TPS data
Estimated Repair Costs
- Under warranty: $0 (Stellantis 3-year/36,000-mile basic + 5-year/60,000-mile powertrain)
- PCM reflash: $0 under warranty
- Throttle body replacement (if out of warranty): $400–$700
Should You DIY This?
DIY feasibility is low. Your 2024 Ram 2500 is fully under warranty. Let the dealer handle it at no cost.