P1103 – Mass Air Flow Sensor In Range But Higher Than Expected (Ford)

By Reinier (Contact Me)
Last Updated 2020-12-19
Automobile Repair Shop Owner

Manufacturer Specific Definitions for P1103

Table of Contents

1. What Does Code P1103 Mean?
2. Where is the P1103 sensor located?
3. What are the common causes of code P1103?
4. What are the symptoms of code P1103?
5. Get Help with P1103

What Does Code P1103 Mean?

OBD II fault code P1103 is a manufacturer specific trouble code that is defined by carmaker Ford, as “Mass Air Flow Sensor In Range But Higher Than Expected”,) and is set when the PCM (Powertrain Control Module) detects an airflow value through the MAF (Mass Airflow) sensor that is higher than expected. Note that this code can set even though the airflow reading may still be within acceptable limits given the current engine speed and torque load.

NOTE: Carmaker Mazda uses a similar definition for code P1103. In this case, the definition is “Mass Airflow Sensor Signal Inconsistent with Engine Speed”, which describes the same problem as the Ford definition.

The primary function of a MAF sensor is to measure the volume of air that is entering the engine. While we need not delve into the finer details of MAF sensor operation here, all modern MAF sensor designs typically use a heated element that generates an electrical current when air flows over it.

In practice, though, the generated electrical current is directly proportional to the volume of air that flows through the sensor. However, since the density (and therefore, the volume of air) is dependent on factors like the relative humidity, barometric pressure, and ambient temperature, the PCM needs to correlate the volume of air as reported by the MAF sensor with input data from other sensors to calculate appropriate fuel delivery strategies.

Thus, the PCM obtains input data from sensors that include the throttle position sensor, intake air temperature sensor, engine coolant temperature sensor, barometric pressure sensor, and others to verify that the MAF sensor is reporting a plausible volume of air passing through it. As a practical matter, the PCM refers to pre-programmed parameters that compare reported airflows to engine speeds and loads; for instance, the airflow through the MAF must fall within a specified range at a specified range of engine speeds. Be sure to consult reliable service information for the programmed values that apply to the affected application to avoid a misdiagnosis.

These values differ between engines, but in all cases, the actual airflow rate or value cannot exceed the maximum allowable desired airflow at any given engine speed and load, because in such a situation, the PCM cannot maintain a stoichiometric air/fuel mixture because its ability to compensate for excessive air flow rates is limited. Put in another way, the PCM cannot make unlimited adaptations to the injector’s pulse widths, which translates into the fact that with an excessive airflow rate, a lean condition is inevitable because the PCM cannot inject enough fuel into the engine to match the excessive airflow entering the engine.

Thus, to prevent a lean condition that it cannot correct, the PCM monitors the airflow (as reported by the MAF sensor) very closely. If a defect, fault, or malfunction occurs that causes the reported airflow to approach or exceed a pre-programmed maximum allowable threshold, the PCM will recognize that it cannot control the air/fuel mixture effectively, and it will set code P1103 and illuminate a warning light as a result.

Where is the P1103 sensor located?

This image shows the location of the MAF sensor on a Ford Ranger application. In all cases though, the MAF sensor will be located in the intake ducting between the air filter housing and the intake manifold, and in many cases, the MAF sensor will attach directly to the intake manifold with several retaining bolts/screws, such as in this example.

Take particular note of the fact that MAF sensor elements must NOT be cleaned with brake or electrical switch cleaners, because these substances remove or damage the special coatings on the elements that make them work. If the element in the MAF sensor appears to be dirty or contaminated with oil, only use cleaners and/or solvents that are specifically formulated and/or approved for use on MAF sensor elements to clean off the element to avoid damaging it.

What are the common causes of code P1103?

The common causes of code P1103 are largely the same across all Ford applications, and could include one or more of the following

• Damaged, defective, unsuitable, or malfunctioning MAF sensor
• Use of unsuitable aftermarket MAF sensors on some applications
• Damaged, defective, unsuitable, or malfunctioning IAT (Intake Air Temperature) sensor
• Damaged, shorted, burnt, disconnected, or corroded wiring and/or connectors
• Air intake restrictions
• Leaks in the intake air system or ducting
• Note that on some Ford applications, some types of EGR (Exhaust Gas Recirculation) system faults and defects can cause this code to set, or contribute to its setting. Therefore, if the affected application is fitted with an EGR system, be sure to scan specifically for active and pending EGR system trouble codes as well
• Failed or failing PCM, but note that since this a rare event, the fault must be sought elsewhere before any control module is reprogrammed or replaced

What are the symptoms of code P1103?

While common symptoms of code P1103 vary somewhat between Ford applications, these could include one or more of the following-

• Stored trouble code and illuminated warning light
• Multiple additional codes may be set and stored along with P1103, and particularly so if the fault involves failures or defects in the EGR system
• Vehicle may be locked into a limp or failsafe mode
• Fueling system may operate in a default (open loop) mode
• Fuel consumption may increase
• Varying degrees of power loss may be present, even if the vehicle is not in a limp mode
• Engine may stall frequently or unexpectedly at low engine speeds
• Idling speed may be higher than specified, or the idling quality may be poor

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