DTC P0101: Mass Airflow (MAF) Sensor Circuit Performance (Esteem 1.8L)

Check MAF sensor and air intake system for blockage. Repair as necessary. If air intake system is okay, connect scan tool to Data Link Connector (DLC). Start engine and allow it to reach normal operating temperature. At idle, MAF sensor value should be 1.5-4.0 g/sec. At 2500 RPM, MAF sensor value should be 5.0-10.0 g/sec. If MAF sensor values are to specification, go to step 5 . If MAF sensor values are not to specification, go to next step.
Ensure ignition is off. Disconnect MAF sensor connector. Turn ignition on. Measure voltage between MAF sensor connector terminal No. 3 (Red/Black wire) and ground. If voltage is 10-14 volts, go to next step. If voltage is not 10-14 volts, repair open circuit in Red/Black wire.
Reconnect MAF sensor connector. Turn ignition on, engine off. Measure voltage (backprobe) between PCM connector C20 terminals No. 24 (Green wire) and No. 27 (Orange wire). Voltage should be .5-1.0 volt. Start and idle engine. Voltage should be 1.3-1.8 volts. If voltage is not to specification, go to next step. If voltage is to specification, check for poor PCM connection. If connection is okay, replace PCM.
Check Green and Orange wires for an open or short circuit. Repair wiring as necessary. If wiring is okay, replace MAF sensor.
Turn ignition on. Measure (backprobe) voltage between PCM connector E91 terminal No. 7 (Green wire) and connector C20 terminal No. 27 (Orange wire). Voltage should be 3.9-5.0 volts. Start and idle engine. Voltage should be 1.4-2.4 volts. If voltages are to specification, replace PCM. If voltages are not to specification, check Manifold Differential Pressure (MDP) sensor. See MANIFOLD DIFFERENTIAL PRESSURE (MDP) SENSOR - ESTEEM (1.8L), GRAND VITARA & VITARA in SYSTEM & COMPONENT TESTING article.