What Does P0121 Mean on a 2024 Jeep Cherokee?
A P0121 code on your 2024 Jeep Cherokee indicates the PCM has detected that the throttle position sensor (TPS) signal doesn't match the expected voltage pattern for your driving conditions. The signal is present but behaves erratically. This is a clue that the throttle system needs professional investigation.
The Cherokee (KL) was available with the 2.4L Tigershark four-cylinder (port injection) or the 3.2L Pentastar V6 (port injection). Both use electronic throttle control with the TPS integrated into the throttle body. On a newer model, carbon buildup is less likely—focus the investigation on software and hardware causes.
Top Causes of P0121 on the 2024 Cherokee
- PCM software calibration – Software updates may address throttle mapping. Likelihood: 35%
- Throttle body defect – Manufacturing issue with the integrated TPS. Likelihood: 30%
- Connector issue – Not fully seated or improperly assembled. Likelihood: 20%
- Electrical interference – Signal noise from other vehicle electronics. Likelihood: 10%
- Carbon buildup – Unlikely at low mileage. Likelihood: 5%
Symptoms You May Notice
- Check Engine Light on
- Rough or inconsistent idle
- Hesitation during acceleration
- Reduced engine power
- Cruise control may not engage
How Serious Is This Code?
P0121 is medium severity. The Cherokee remains drivable, but throttle response may be compromised. Address it soon—schedule a dealer appointment within the week. Warranty coverage should apply.
Diagnostic Steps
- Take the vehicle to your Jeep dealer for warranty diagnosis
- Dealer uses wiTECH for full diagnostic analysis
- Check for TSBs and PCM software updates
- Inspect throttle body connector and wiring
- Monitor live TPS data for anomalies
- Replace throttle body if hardware fault confirmed
Estimated Repair Costs
- Under warranty: $0 (covered by 3-year/36,000-mile basic warranty)
- PCM reflash: $0 under warranty
- Throttle body replacement (if out of warranty): $350–$550
Should You DIY This?
DIY feasibility is low. Your Cherokee should be under Stellantis' 3-year/36,000-mile basic warranty and 5-year/60,000-mile powertrain warranty. Let the dealer diagnose and repair at no charge. PCM updates require the wiTECH system.