P1103 code definition
The Powertrain Control Module (PCM) stores a P1103 trouble code when the voltage signal from the Mass Air Flow (MAF) sensor is higher than normal but still falls within the range specified by the manufacturer. In addition to a P1103 trouble code, other related codes the PCM might store include a P1100, P1101, P1102, and P1104 code.
What the P1103 code means
The MAF sensor sends data to the PCM in the form of a voltage signal. If the PCM receives a voltage signal from the MAF sensor that is higher than what the manufacturer has specified but the signal still falls within established parameters, a P1103 trouble code is stored and the check engine light illuminates.
What causes the P1103 code?
A common cause of a P1103 trouble code is faulty or loose wiring and connectors within the MAF sensor wiring harness. In addition to this, a leak in the vacuum system, either before or after the MAF sensor, can cause the PCM to store this code. A clogged MAF sensor screen or a dirty or bad MAF sensor are some other likely causes of a code storage.
What are the symptoms of the P1103 code?
Symptoms of a P1103 trouble code include stalling when idling, an erratically running engine, and reduced power while accelerating. In addition, a vehicle can suffer from reduced fuel efficiency from the conditions that cause a P1103 trouble code.
How does a mechanic diagnose the P1103 code?
To diagnose the P1103 trouble code, a mechanic needs to use an advanced scanner, an evaporative smoke tester, and a digital volt/ohm meter. Once the mechanic has the necessary equipment, they need to perform the following steps:
- Inspect all wiring, connectors, and components associated with the MAF sensor, including the wiring harness. The mechanic is looking for any damaged, loose, or faulty wiring, connectors, or components when doing this inspection.
- Remove the air filter and determine if it needs replacing.
- While the mechanic has the air filter out, they should carefully remove the MAF sensor for cleaning with a CRC 05110 spray cleaner.
- Next, once all components are cleaned, repaired, or replaced, the mechanic should clear the code and test the system, with the vehicle running, to see if the code returns.
- If the code returns, the mechanic should first download any freeze frame data and stored trouble codes and then perform a smoke test to check for leaks within the vacuum system using an evaporative smoke tester.
- Then they should clear the code after fixing any leaks and see if the code returns.
- If the code returns, they should use a digital volt/ohm meter to test the voltage and ground signal of the MAF sensor.
- If there is no voltage or ground signal at the MAF sensor, the mechanic should disconnect the PCM and check the continuity of the MAF sensor and circuit with the battery ground. The mechanic should also test the continuity between the MAF sensor circuit and the PCM.
- Once all of the necessary repairs are made, the mechanic should clear the code and retest the system to see if the code returns.
Common mistakes when diagnosing the P1103 code
A mistake common to P1103 trouble code diagnosing is for the mechanic to replace the MAF sensor without checking the wiring for fault, damage, or looseness. The result is that the problem is not fixed and the code returns.
How serious is the P1103 code?
While a vehicle can still operate with a P1103 trouble code stored, the erratic running condition of the engine and the subsequent stalling while idling can make the vehicle difficult to drive. The reduced fuel efficiency also leads to more costs when putting fuel into the vehicle. Because of this, it is recommended that you deal with a P1103 trouble code as soon as possible.
What repairs can fix the P1103 code?
Repairing a P1103 trouble code requires a mechanic to do the following:
- Replace any faulty or damaged wiring, connectors, or components within the MAF sensor wiring harness. In addition to repairing and replacing items, the mechanic should check for any loose wiring and connectors.
- If the air filter is dirty upon inspection, the mechanic should replace it with a new one.
- In addition, before reinstalling the air filter, the mechanic should remove and clean the MAF sensor with a CRC 05110 spray cleaner. The mechanic should be careful when removing the sensor so as not to damage the connecting wiring, which is delicate.
- They should then repair any air leaks in the vacuum system.
- Next, they should replace the MAF sensor if further testing determines it is bad.
- If the PCM tests as bad, the mechanic should replace that component as well. Replacing the PCM requires the mechanic to program it upon installation.
Need help with a P1103 code?
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