P0103

DTC P0103 MAF Sensor Circuit High Frequency (1 Of 2):

DTC P0103 MAF Sensor Circuit High Frequency (2 Of 2):

Mass Air Flow System:

Circuit Description
The Mass Air Flow (MAF) sensor measures the amount of air entering the engine during a given time. The Vehicle Control Module (VCM) uses the Mass Air Flow information for fuel delivery calculations. A large quantity of air entering the engine indicates an acceleration or high load situation, while a small quantity of air indicates deceleration or idle.

The MAF sensor produces a frequency signal which a scan tool can monitor. The frequency varies within a range of around 5 to 7 g/s at idle to near 125 g/s at maximum engine load. This DTC sets if the signal from the MAF sensor is above the possible range of a normally operating MAF sensor. This DTC is a type A DTC.

Conditions For Setting The DTC

Power Up Test
^ The engine is off.
^ The ignition is ON for 0.7 seconds.
^ The MAF is at least 300 g/s.

High Frequency Test
^ The engine is running.
^ Engine Run Time is at least 2 seconds.
^ System voltage is at least 10 volts.
^ Throttle Position is less than 89.8%.
^ The MAF sensor is at least 300 g/s.
^ Above conditions present for 2 seconds.

Action Taken When The DTC Sets

^ The VCM illuminates the Malfunction Indicator Lamp (MIL) the first time the fault is detected.
^ The VCM calculates an airflow value based on Idle Air Control (IAC) valve position, throttle position, engine speed and barometric pressure.
^ The VCM stores conditions which were present when the DTC set as the Freeze Frame and the Fail Records data.

Conditions For Clearing The MIL/DTC

^ The VCM turns the MIL off on the third consecutive trip cycle during which the diagnostic has been run and the fault condition is no longer present.
^ A history DTC clears after 40 consecutive warm.up cycles have occurred without a fault.
^ Using the scan tool Clear Info function or disconnecting the VCM battery feed clears the DTC.

Diagnostic Aids

Check for the following conditions:

^ Poor connection at VCM Inspect harness connectors for the following conditions:

- Backed out terminals.
- Improper mating.
- Broken locks.
- Improperly formed or damaged terminals.
- Poor terminal to wire connection.

^ A misrouted harness. Inspect the MAF sensor harness in order to ensure that it is not routed too close to the high voltage wires such as spark plug leads.
^ A damaged 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.

Test Description
The numbers below refer to the step numbers on the diagnostic table:

2. This step verifies that the problem is present at idle.
4. A frequency reading with the MAF sensor connector disconnected indicates an Electromagnetic Interference (EMI) related fault or a poor connection.
9. This vehicle is equipped with a VCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the VCM is being replaced, the new VCM must be programmed. Refer to VCM Replacement/Programming. Service and Repair