Diagnostic Aids

Check for any of the following conditions:

• Excessive deposits on the throttle plate or throttle bore
• A sticking or binding throttle plate
• A misrouted wiring harness-Inspect the MAF sensor harness to ensure that the harness is not routed too close to high voltage wires such as spark plug leads.
• A damaged wiring harness-Inspect the wiring harness for damage. If the harness appears to be OK, observe the scan tool while moving connectors and wiring harnesses related to the MAF sensor. A change in the display will indicate the location of the fault.
• Observe the heated oxygen (HO2S) voltage and fuel trim readings with a scan tool. If the HO2S voltage is fixed low, while the fuel trim is constantly high, check the MAF sensor signal circuit for resistance. High circuit resistance can cause the sensor to read a lower volume of air than actual, resulting in a lean fueling condition.
• A plugged intake air duct or a dirty air filter element-A wide-open throttle (WOT) acceleration from a stop should cause the mass air flow parameter displayed on a scan tool to increase from about 2-3.5 g/s at idle to about 90-100 g/s or more at the time of the 1-2 shift. If the detected air flow is significantly smaller, check for a restriction or blockage in the intake air system.

An intermittent malfunction may be caused by a fault in the MAF sensor circuit. Inspect the wiring harness and components for an intermittent condition. Refer to Intermittent Conditions .

If the DTC P0101 cannot be duplicated, the information included in the Freeze Frame data can be useful in determining vehicle operating conditions when the DTC was first set.

If any wiring repairs need to be made, refer to Wiring Repairs in Wiring Systems.