P0103

Wiring Diagram:

Circuit Description
The Mass Air Flow (MAF) sensor measures the amount of air which passes through it 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 fuel delivery. The PCM calculates the engine's 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 located between the air intake tube and the air cleaner in the LH front area of the engine compartment.

Conditions for Running the DTC
The engine is running.

Conditions for Setting the DTC
^ MAF sensor output current is greater than 4.9 mA.
^ Condition is present for longer than 5 seconds.

Action Taken When the DTC Sets
^ The Malfunction Indicator Lamp (MIL) will illuminate.
^ The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame buffer.
^ The PCM will enter the Fail-Safe Function and determine injector drive time according to TP sensor and engine speed.

Conditions for Clearing the MIL/DTC
^ The MIL will turn off after three consecutively passing cycles without a fault present.
^ A History DTC will clear after 40 consecutive warm-up cycles without a fault.
^ DTC(s) can be cleared by using a scan tool or by disconnecting the PCM battery feed.

Diagnostic Aids
Check for any of the following conditions:
^ A poor connection at the PCM. Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and a poor terminal to wire connection.
^ A misrouted wiring harness. Inspect the MAF sensor harness to ensure that it 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.
^ A plugged intake air duct or a dirty air filter element. A wide-open throttle acceleration from a stop should cause the Mass Air Flow displayed on a scan tool to increase from about 2 to 3.5 g/s at idle to 100 g/s or greater at the time of the 1-2 shift. If not, check for a restriction.

If the DTC P0103 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.

Test Description
The numbers below refer to the step numbers in the Diagnostic Table.
1. The Powertrain OBD System Check 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.
3. Review Freeze Frame data to determine when the DTC set. Always record this information.
5. Normal voltage at idle for the MAF sensor signal should be 1.7 V to 2.0 V, this voltage reading should increase steadily to 5 V when engine speed is increased to approximately 4000 rpm.