What Does P1428 Mean?
The Mass Air Flow (MAF) sensor circuit has an open circuit detected. The ECM is not receiving a signal from the MAF sensor due to broken wiring, poor connection, or sensor failure.
Common Causes
35%
Disconnected or corroded MAF sensor electrical connector
30%
Failed MAF sensor with open internal circuit
20%
Broken or cut wiring between MAF sensor and ECM
10%
Failed ECM power supply to MAF sensor (5V reference circuit)
5%
Dirty or contaminated MAF sensor element preventing operation
Diagnostic Steps
1
Step 1: Verify MAF sensor connector is fully seated and locked, inspect for corrosion or damage
2
Step 2: Check for 5V reference voltage and good ground at MAF sensor connector with key on, engine off
3
Step 3: Measure continuity of all wires between MAF connector and ECM connector using wiring diagram
4
Step 4: If power and ground are present, monitor MAF sensor signal voltage while operating (should vary with airflow)
5
Step 5: Replace MAF sensor if all circuits test good but no signal is present
Estimated Repair Cost
$150 - $450
Parts + labor, varies by vehicle and location
The Mass Air Flow (MAF) sensor circuit has an open circuit detected. The ECM is not receiving a signal from the MAF sensor due to broken wiring, poor connection, or sensor failure.
The most common cause of P1428 (EGI Mini - MAF Failed Open Circuit) is: Disconnected or corroded MAF sensor electrical connector
Typical repair costs for P1428 range from $150 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle may run poorly or not start. If running, expect rough idle and reduced power. Safe for short-distance driving but repair promptly.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1428 to identify the root cause.
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Quick Info
Category
Powertrain
System
Air/Fuel Metering
Difficulty
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Manufacturer
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