Tracking Down P0446 on Your 2021 Jeep Gladiator
A P0446 code on your 2021 Jeep Gladiator indicates an EVAP vent control circuit malfunction. The Gladiator JT — Jeep's body-on-frame midsize truck sharing its platform with the Wrangler JL — uses Stellantis' ESIM (Evaporative System Integrity Monitor) for EVAP system management.
The Gladiator's truck bed and longer wheelbase mean more EVAP system plumbing than the Wrangler, with additional routing along the frame rails. At four years old, your basic warranty has expired but the federal emissions warranty provides coverage.
Symptoms Under Investigation
- Check engine light on with P0446 stored
- Fuel nozzle shutting off during fill-ups
- EVAP readiness monitor not completing
- Possible companion codes P0441, P0455, or P0456
Prime Suspects
- ESIM Module Failure (High Likelihood): The integrated ESIM unit handles both vent control and leak detection. Off-road exposure and vibration on the body-on-frame Gladiator can accelerate wear. Parts $95–$180, labor $105–$215.
- ESIM Connector Corrosion (High Likelihood): Off-road use, water crossings, and undercarriage exposure make connector corrosion more common on the Gladiator than typical vehicles. Repair costs $75–$170.
- EVAP Line Damage Along Frame (Medium Likelihood): The Gladiator's frame-mounted EVAP lines can be damaged by off-road obstacles, trail debris, or aftermarket accessories. Repair costs $85–$260.
- Charcoal Canister Contamination (Medium Likelihood): Water intrusion during fording or heavy rain can damage the canister. Parts $150–$310, labor $115–$230.
- Aftermarket Accessory Interference (Low Likelihood): Skid plates, lift kits, or bed-mounted accessories may pinch or damage EVAP lines. Repair costs $60–$180.
Diagnostic Approach
- Scan all codes and freeze frame data — note if off-road conditions were logged
- Inspect ESIM module and connector for damage, corrosion, or water intrusion
- Check EVAP lines along the frame rails for crush damage or disconnections
- Test ESIM operation using wiTECH bidirectional controls
- Verify wiring continuity from ESIM to PCM
- Smoke test the system if leak codes accompany P0446
Repair Estimates
- ESIM module replacement: $200–$395
- Connector repair: $75–$170
- EVAP line repair: $85–$260
- Charcoal canister replacement: $265–$540
- Diagnostic fee: $95–$155
Safe to Drive?
Yes. P0446 doesn't affect your Gladiator's 3.6L Pentastar V6 (285 hp), 6-speed manual or 8-speed automatic, or 4WD capability. Towing capacity and off-road performance are unaffected. The truck drives normally.
Warranty Coverage
Your 2021 Gladiator's basic warranty (3 years/36,000 miles) has likely expired. The federal emissions warranty covers EVAP components for 8 years/80,000 miles through 2029. Contact your Jeep dealer to confirm eligibility.