The Wiggle Test
The technician received a code (P0101) for a faulty (MAF) Mass Air Flow sensor. Leaving a MAF sensor's connector loose wreaks havoc on the engine's operation. Visually inspect this connection and component to make sure a loose connector or faulty wire isn't at fault.
While monitoring the scanner and wiggling the plug or connector, the technician can tell if the connector is at fault. It's important to rule out circuit problems like the connector or poor wiring before replacing expensive components.
Notice the technician is wiggling the wires as well as the connector. Wires can break inside the insulation, resulting in resistance and open circuits. Heat may be felt from that spot in the frayed wiring. Perform a wiggle test on any circuit where a loose connector or a broken wire is suspected. Spaded plugs and connectors can be replaced or repaired to restore the integrity of the circuit.