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.

The ignition key is ON or the engine is running.

Check for any of the following conditions:

If 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. Road 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 diagnostic has not yet run. When the DTC P0102 does not appear in the Not Ran Since Code Cleared list, the DTC P0102 diagnostic has run. If the MIL is NOT illuminated, and there is no Pending DTC Status in DTC Information, the DTC P0102 diagnostic has passed. The DTCs MUST be cleared in 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 to Intermittent Conditions .

If the DTC P0102 cannot be duplicated, the information included in the Freeze Frame data can be useful in determining the vehicle operating conditions when the DTC was first set.

The numbers below refer to the step numbers in the diagnostic table.

1. The Diagnostic System Check-Engine Controls prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.

2. This step will determine if the fault is present.

7. This step checks for an open or a short in the MAF sensor signal circuit between the MAF sensor and the PCM.

10. Clearing the DTCs by removing the DOME fuse also clears the PCM long term memory. Using the scan tool to clear DTCs leaves the long term memory active. DTC emitting diagnostics may not run to completion as expected unless the long term memory is cleared. Removal of the DOME fuse also clears the time display of the radio. The DTC P0102 diagnostic can be monitored 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 diagnostic has not yet run. When the DTC P0102 does not appear in the Not Ran Since Code Cleared list, the DTC P0102 diagnostic has run. If the MIL is NOT illuminated, and there is no Pending DTC Status in DTC Information, the DTC P0102 diagnostic has passed. The DTCs MUST be cleared in 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.