Technical Description of OBD-II Trouble Code
The current range/performance of the Diesel Intake Air Flow Control Motor is not within the expected parameters.
What does that mean?
This diagnostic trouble code (DTC) is a generic powertrain/engine code that can apply to all diesel OBD-II equipped engines. However, it is more commonly found in certain Chevy, Dodge, Ford, and GMC trucks.
While the code is generic, the specific repair steps may vary depending on the year, make, model, and powertrain configuration of the vehicle.
The Diesel Intake Air Flow Control System (DIAFCS) is typically located on the intake manifold in the intake air stream. This system is responsible for controlling the amount of incoming airflow by adjusting a motor operated by the Powertrain Control Module (PCM). The motor opens and closes a throttle plate to regulate the airflow.
The PCM relies on the Diesel Intake Airflow Position Sensor (also known as a MAF sensor) to determine the amount of clean, filtered air entering the engine. When the air flow control system is activated, the PCM should detect a change in airflow. If no change is detected, there may be an issue with the DIAFCS system or the MAF sensor. These trouble codes are set when the input does not match the normal engine operating conditions stored in the PCM’s memory, even for a brief moment.
The PCM also checks the voltage signal from the DIAFCS to ensure it is correct during the initial Key On phase.
The code P02EB is set when there is a detected problem with the current range or performance of the diesel intake air flow control motor. This problem could be due to mechanical issues (such as physical damage to the control system causing an electrical fault) or electrical issues (related to the DIAFCS motor circuit). It is important not to overlook these issues during the troubleshooting process, especially when dealing with intermittent problems.
The troubleshooting steps may vary depending on the manufacturer, type of DIAFCS motor/control, and wire colors.
What is the severity of this DTC?
In all cases, the severity of this DTC is considered to be not severe. If the cause is mechanical, the typical symptom is low idle speed. If it is an electrical failure, the PCM can compensate adequately.
What are some of the symptoms of the code?
Some symptoms of a P02EB trouble code may include:
What are some of the common causes of the code?
Some possible causes for this P02EB code may include:
What are some P02EB troubleshooting steps?
A good starting point is always to check for technical service bulletins (TSB) for your vehicle. Your issue may be a known issue with a known fix provided by the manufacturer, which can save you time and money during diagnosis.
Next, locate the DIAFCS motor/control system on your vehicle. This motor/control is usually bolted to the intake manifold in the intake air stream. Once located, visually inspect the connector and wiring for any signs of damage or wear. Look for scraping, rubbing, bare wires, burn spots, or melted plastic. Pull the connector apart and carefully inspect the terminals inside for any signs of burning or corrosion. If needed, clean the terminals using electrical contact cleaner and a plastic bristle brush. After cleaning, apply electrical grease to ensure proper contact.
If a mechanical code was set, use intake cleaner and a clean rag to remove carbon deposits behind the throttle plate of the motor control system. Be careful not to spray these deposits into the engine, as it can cause poor running, misfires, and potential damage to the catalytic converter and engine.
If you have a scan tool, clear the diagnostic trouble codes from memory and see if the P02EB code returns. If it does not, then the issue was most likely related to the connections.
If the P02EB code does return, further testing of the DIAFCS and its associated circuits will be necessary. With the Key Off, disconnect the electrical connector at the DIAFCS motor/control. Use a Digital Voltmeter to check the voltage between the ground terminal and the motor terminal at the DIAFCS sensor wiring harness connector. The voltmeter should read 12 volts according to the manufacturer’s specifications. If not, repair the power or ground wire, or replace the PCM if necessary. Refer to the manufacturer’s specifications for complete test procedures specific to your vehicle if you are unsure.
If the previous test passed and you continue to receive a P02EB code, it is likely that the DIAFCS motor/control has failed. However, a failed PCM cannot be ruled out until the DIAFCS motor/control has been replaced. If you are unsure, it is recommended to seek assistance from a trained automotive diagnostician. Keep in mind that PCMs must be programmed or calibrated to the vehicle for proper installation.
