P0102: Mass Air Flow (MAF) Circuit Low Input
The ECM detects that the MAF sensor voltage signal has dropped below 0.20V (or frequency < 1.0 kHz) for more than 4 engine cycles, indicating an open circuit, unplugged sensor, or short-to-ground.
Driveability & Safety Advisory
Limp mode active. Vehicle will start and run with sluggish acceleration.
Official Manufacturer TSB Advisories
Factory Condition: MAF wiring harness rubs against battery tray corner, slicing the signal ground wire.
Physical Component Location & Service Access
Mounted in air inlet duct between air cleaner box and throttle body.
Electrical Specifications & Live PID Benchmarks
Scan Tool Live Data Targets
Digital Multimeter (DMM) Specs
Documented Model-Specific Case Studies
Root Cause: Blown EFI fuse cutting 12V to MAF.
Verified Fix: Replace 15A EFI fuse and inspect harness for short.
Technician Inspection & Testing Workflow
Check if MAF is plugged in properly and lock tab is engaged.
Check engine bay fuse box for blown MAF / Engine Sensor fuse.
Measure voltage at MAF connector pins with key ON.
Recommended Diagnostic Tools & Verified Parts
BlueDriver Bluetooth Pro OBDII Scan Tool
Wireless sensor telemetry & enhanced diagnostics (Engine, ABS, Airbag). Delivers verified vehicle repair reports.
Autel AutoLink AL519 / AL319 OBD2 Scanner
Color screen standalone scanner. One-click I/M emissions readiness status, freeze-frame data, live DTC reset.
CRC Mass Air Flow & Throttle Body Cleaner Twin Pack
OEM-approved fast-drying solvent to safely clean delicate platinum hot-wire MAF sensors and restore accurate fuel trims.
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Cost Breakdown
Tools & Parts Matrix
Diagnostic Questions & Answers
Why did my car throw P0102 right after changing the air filter?
In over 70% of cases, the technician forgot to reconnect the MAF sensor plug or broke the wiring harness connector lock.