P0102

Refer to Engine Controls Schematics.

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

CIRCUIT DESCRIPTION
The Mass Air Flow (MAF) sensor measures the amount of air which passes through to the engine. The PCM uses the mass air flow information 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 around 2000 Hertz at idle to about 10,000 Hertz at maximum engine load. DTC P0102 will be set if the signal frequency from the MAF sensor is lower than the possible range of a normally operating MAF sensor.

CONDITIONS FOR RUNNING THE DTC
^ The engine is running.
^ Above conditions are present for over 0.5 seconds.
^ Ignition voltage is more than 8.0 volts.
^ IAC is more than 2 counts

CONDITIONS FOR SETTING THE DTC
MAF signal frequency is below 1200 Hertz.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM will illuminate the Malfunction Indicator Lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.
^ The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.
^ If the misfire is determined to be catalyst damaging, the PCM will flash the MIL.

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

DIAGNOSTIC AIDS
Inspect for the following conditions:
^ Misrouted harness-Ensure that the MAF sensor harness is not routed too close to high voltage wires such as spark plug leads.
^ Plugged intake air duct or 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 4-6 gm/s at idle to 100 gm/s or more at the time of the 1-2 shift. If not, inspect for a restriction.

IMPORTANT: Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.

^ Poor terminal connection-Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Use a corresponding mating terminal to test for proper tension.
^ Damaged harness-Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault.
^ PCM and engine grounds for clean and secure connections

If the DTC is determined to be intermittent, reviewing the Failure Records can be useful in determining when 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.
5. A voltage reading of less than 4.0 or over 6.0 volts at the MAF sensor signal circuit indicates a malfunction in the wiring or a poor connection.
6. Verifies that ignition feed voltage and a good ground are available at the MAF sensor.
13. This vehicle is equipped with a PCM which utilizes an electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.