6-1450 Engine Controls - 2.5L (LE8) DTC P0102 Circuit Description The DTC P0102 mass air flow (MAF) sensor circuit low voltage diagnostic monitors the MAF sensor signal. The MAF sensor measures the amount of air which passes through the sensor in a given amount of time. The powertrain control module (PCM) uses this information to determine the operating requirements of the engine in order to control the fuel delivery. The PCM calculates the engines fuel requirements by monitoring the current flow on the signal wire from the MAF sensor. When the volume of air entering the MAF sensor increases, the current flow seen by the PCM from the MAF sensor also increases. When the air flow decreases. the current seen by the PCM also decreases. The MAF sensor is an integral part of the throttle body assembly. Conditions for Running the DTC The ignition key is ON or the engine is running. Conditions for Setting the DTC - The MAF sensor output current is less than 0.64 mA - The condition is present for more than 5 seconds Action Taken When the DTC Sets - The PCM illuminates the malfunction indicator lamp (MIL). - The PCM records the operating conditions at the time the diagnostic fails. This information is stored in the Freeze Frame buffer. - The PCM enters the Fail-safe mode and determines the injector drive time and the idle air control (lAC) duty cycle according to the throttle position (TP) sensor input and the engine speed. Conditions for Clearing the MiL/DTC - The MIL turns OFF after 3 consecutively passing trips without a fault present. - A History DTC clears after 40 consecutive warm-up cycles without a fault. - Perform the scan tool clear DTC information function in order to clear the DTC. .is NOT illuminated, and there is no Pending Enginl Diagnostic Aids Check for any of the following conditions: - A misrouted wiring harness. inspect the MAF sensor harness to ensure that the harness is not routed too close to high voltage or high amperage circuits. - A damaged wiring harness. inspect the wiring harness for damage. if the harness appears to bet OK, observe the scan tool while moving the J connectors and the wiring harnesses related to the MAF sensor. A change in the display will i indicate the location of the fault. - Check for an air intake restriction. it a DTC P0102 is intermittent, driving the vehicle under the following conditions can verify whether the ; fault is present. Perform the scan tool clear DTC information function. Fioad test the vehicle while monitoring the DTC P0102 diagnostic on the scan tool under the Not Ran Since Code Cleared selection in , the DTC information menu. if a DTC P0102 appears in the Not Ran Since Code Cleared list, the DTC P0102 I diagnostic has not yet run. When the DTC P0102 , does not appear in the Not Fian Since Code Cleared . list, the DTC P0102 diagnostic has run. If the MiL l DTC Status in DTC information, the DTC P0102 diagnostic has passed. The DTCs MUST be clearedi order to view the Current Status of the Not Ran Since Code Cleared list. DO NOT forget that the Not Ran Since Code Cleared list only indicates that the test has run, not whether the test passed or failed The DTC Information screen must be checked for Current or Pending status, in order to determine the outcome of the diagnostic test involved. 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 Intermittent Conditions. if the DTC P0102 cannot be duplicated, the informa' included in the Freeze Frame data can be useful in determining the vehicle operating conditions when the DTC was first set.