Investigating P0100 on Your 2021 Ford Bronco Sport
A P0100 code on your 2021 Ford Bronco Sport means the PCM has detected a malfunction in the mass air flow (MAF) sensor circuit. Your Bronco Sport uses the 1.5L EcoBoost three-cylinder (base/Big Bend/Outer Banks) or 2.0L EcoBoost four-cylinder (Badlands), both turbocharged engines relying on accurate MAF data.
Symptoms
- Check engine light on
- Rough or unstable idle
- Hesitation during acceleration
- Reduced power
- Poor fuel economy
- Possible stalling
Common Causes
- Contaminated MAF sensor (35%) — Four-plus years of dust and debris, accelerated by off-road use common with Bronco Sport owners.
- Wiring or connector issues (22%) — Heat and vibration.
- Faulty MAF sensor (18%) — Internal failure.
- Intake or intercooler piping leak (13%) — EcoBoost turbo piping connections loosening.
- Air filter restriction (8%) — Overdue change.
- PCM issue (4%) — Rare.
Diagnostic Steps
- MAF sensor cleaning — Remove and clean with dedicated MAF cleaner spray.
- Intake and turbo piping inspection — Check intercooler piping on both engine options.
- Air filter check — Replace if dirty.
- Connector inspection — Check for corrosion or looseness.
- Scan tool data — Verify MAF readings.
- MAF replacement — If cleaning doesn't resolve the code.
Repair Costs
- MAF cleaning: $10–$15 (DIY)
- Air filter: $15–$28 (DIY)
- MAF sensor: $125–$305
- Intake boot/piping: $80–$210
- Wiring repair: $90–$265
Warranty
Your 2021 Bronco Sport's basic warranty has expired. The federal emissions warranty covers the MAF sensor for 8 years/80,000 miles through 2029.