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P1102 OBD-II Trouble Code: Mass Airflow Sensor in Range But Lower Than Expected

diagnostic check engine light

P1102 code definition

When the voltage coming from the Mass Air Flow (MAF) sensor to the Powertrain Control Module (PCM) is low but within range, a P1102 trouble code is stored. Other trouble codes related to this code include a P1100, P1101, P1103, and P1104 code.

What the P1102 code means

The MAF sensor communicates with the PCM using voltage. When this voltage registers as lower than normal, but still falls within the manufacturer's specified range, a P1102 trouble code is stored by the PCM and the check engine light illuminates.

What causes the P1102 code?

Some possible causes of a P1102 trouble code includes shorted wiring or a loose connection within the MAF sensor harness, an air leak in the vacuum system before or after the sensor, or a bad or dirty MAF sensor. A clogged MAF sensor screen can also cause the voltage from the MAF sensor to register as too low. In some cases, the problem is caused by a poor electrical connection with the MAF sensor circuit.

What are the symptoms of the P1102 code?

Some of the more common symptoms of a P1102 trouble code storage include an erratically running engine, less power when accelerating, and stalling while idling. Another problem caused by a P1102 trouble code is problems with the fuel mixture, which can lead to problems with the vehicle's engine.

How does a mechanic diagnose the P1102 code?

Diagnosing a P1102 trouble code requires the use of an advanced scanner and a digital volt/ohm meter by the mechanic. In addition, the mechanic should perform the following diagnostic steps:

  • Visually inspect the wiring, connectors, and components of the MAF sensor harness, looking for any damaged, loose, or faulty items.
  • Pull out the air filter to see if it needs replacing.
  • While the air filter is out, remove the MAF sensor carefully with a flat head screwdriver for cleaning.
  • Replace the MAF sensor and air filter. Clear the code and test the system to see if the code persists.
  • Download any freeze frame data and stored codes if the trouble code returns.
  • Perform a smoke test on the vacuum system and look for leaks, especially before and after the MAF sensor.
  • Connect the digital volt/ohm meter to the MAF sensor, testing the sensor's reference voltage and ground signal.
  • If the mechanic detects no voltage or ground signal, they should disconnect the PCM and other related modules before testing the sensors continuity with the battery ground. The mechanic should compare their findings to the manufacturer's specifications.
  • The mechanic should also test the continuity between the PCM and MAF sensor.
  • Finally, the mechanic should clear the P1102 trouble code and retest the system to see if the code is stored again.

Common mistakes when diagnosing the P1102 code

Mechanics often make the mistake of replacing the MAF sensor without trying to see if cleaning it with a CRC 05110 spray cleaner works first. Often, cleaning the sensor can lead to it operating properly and not require the expense of purchasing a replacement part. Also, the mechanic should try replacing the air filter before replacing the MAF sensor.

How serious is the P1102 code?

The problems often associated with the storage of a P1102 trouble code means that you should have the code diagnosed and fixed as soon as possible. In addition to the rough operation, stalling, and reduced fuel efficiency issues, allowing this code to continue without repairing can lead to internal engine damage over time.

What repairs can fix the P1102 code?

To repair a P1102 trouble code, the mechanic must perform the following steps:

  • The mechanic should first replace any faulty or damaged wiring, connectors, or components within the MAF sensor harness. The mechanic should also check the wiring and connectors to see if they are disconnected.
  • Replace the air filter if it is dirty.
  • Clean the MAF sensor using a CRC 05110 spray cleaner.
  • Repair any leaks within the vacuum system.
  • Replace the MAF sensor if further tests determine it is bad after the mechanic cleans it.
  • If for some reason the PCM tests as faulty, reprogram or replace the component. When replacing the PCM, it needs reprogramming.

Need help with a P1102 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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