P0103

Diagnostic Chart:

Schematic:

CIRCUIT DESCRIPTION
The Mass Air Flow (MAF) sensor measures the amount of air which passes through it into the engine during a given time. The Powertrain Control Module (PCM) uses the mass air flow information in order to monitor engine operating conditions 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 can be monitored using a scan tool. The frequency will vary within a range of approximately 2000 Hertz at idle to approximately 10,000 Hertz at maximum engine load. DTC P0103 will be set if the signal frequency from the MAF sensor is higher than the possible range of a normally operating MAF sensor.

CONDITIONS FOR RUNNING THE DTC
^ The engine is running.
^ The TP angle is less than 50%.
^ The system voltage is more than 9 volts.

CONDITIONS FOR SETTING THE DTC
The MAF signal frequency is more than 11,500 Hertz.
^ The above conditions are present for longer than 0.5 seconds + 400 3X reference periods, or 133 crankshaft revolutions.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM will illuminate the Malfunction Indicator Lamp (MIL) the first time the malfunction is detected.
^ The PCM calculates an airflow value based on the idle air control valve position, the throttle position, the RPM and the barometric pressure.
^ The PCM will store conditions which were present when the DTC set as Freeze Frame and the Fail Records data.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The PCM will turn the MIL OFF during the third consecutive trip in which the diagnostic has been run and passed.
^ The history DTC wilt clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The DTC can be cleared by using the scan tool Clear Info function or by disconnecting the PCM battery feed.

DIAGNOSTIC AIDS
Check for 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 poor terminal-to-wire connection. Use a corresponding mating terminal to check for proper terminal tension.
^ A misrouted 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 harness
Inspect the wiring harness for damage.
^ If the harness appears to be OK, observe the scan tool while moving the connectors and the wiring harnesses that are related to the MAF sensor. A change in the display will indicate the location of the malfunction.

If DTC P0103 cannot be duplicated, the information included in the Fail Records data can be useful in determining the vehicle mileage since the DTC was last set.

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 malfunction or a poor connection.
9. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM).