What Does P0121 Mean on a 2024 Jeep Gladiator?
A P0121 code on your 2024 Jeep Gladiator signals that the PCM has detected an abnormal voltage pattern from the throttle position sensor (TPS). The signal exists but doesn't match what the computer expects given your driving inputs. On a nearly new Gladiator, this is an uncommon finding that warrants an immediate dealer visit.
The 2024 Gladiator (JT) features the 3.6L Pentastar V6 with port fuel injection as its primary engine. The electronic throttle body integrates the TPS internally. At near-zero mileage, carbon buildup is not a realistic cause—the investigation should focus on software and factory quality issues.
Top Causes of P0121 on the 2024 Gladiator
- PCM software calibration – New model year may need a throttle control update. Likelihood: 35%
- Factory throttle body defect – Manufacturing issue with the TPS. Likelihood: 25%
- Connector not properly seated – Assembly-line oversight. Likelihood: 20%
- Electrical interference – Aftermarket accessories (lights, winch) causing signal noise. Likelihood: 15%
- Carbon buildup – Extremely unlikely at low mileage. Likelihood: 5%
Symptoms You May Notice
- Check Engine Light on
- Rough or inconsistent idle
- Hesitation during acceleration
- ESC warnings
- Cruise control inoperative
How Serious Is This Code?
P0121 is medium severity. Your 2024 Gladiator remains drivable, but throttle unpredictability is a concern—especially if you use it off-road where precise throttle control matters. Address it soon—schedule a dealer visit this week.
Diagnostic Steps
- Take the Gladiator to your Jeep dealer—full warranty applies
- Dealer will use wiTECH for comprehensive diagnosis
- Check for TSBs and PCM software updates for the 2024 Gladiator
- Inspect throttle body connector and wiring quality
- If aftermarket accessories are installed, check for electrical interference
- Monitor live TPS data during test drive
Estimated Repair Costs
- Under warranty: $0 (covered by Stellantis 3-year/36,000-mile basic warranty)
- PCM reflash: $0 under warranty
- Throttle body replacement (if out of warranty): $350–$600
Should You DIY This?
DIY feasibility is low. Your 2024 Gladiator is fully covered under Stellantis' 3-year/36,000-mile basic warranty and 5-year/60,000-mile powertrain warranty. Let the dealer fix it at no charge. If you've added aftermarket electronics, mention them to the technician. PCM updates require the dealer's wiTECH system.