DTC Code P02E5 – What does this code mean?

<ul> <li><b>Malfunction Indicator Light On</b>: The Malfunction Indicator Light (MIL) will illuminate, indicating an issue with the diesel intake air flow control. This is often the first sign of a problem.</li> <li><b>Low Idle Speed</b>: The vehicle may experience a low idle speed, which can be linked to the diesel intake air flow control being stuck closed, affecting the engine's air intake.</li> <li><b>Flashing Electronic Throttle Control Symbol</b>: A flashing Electronic Throttle Control (ETC) symbol may appear on the dashboard, indicating a problem with the air flow control system.</li> <li><b>No Regeneration of Diesel Particulate Filter</b>: The diesel particulate filter (DPF) may fail to regenerate, leading to soot build-up. This can eventually cause a loss of power as the DPF becomes clogged.</li> </ul>

<ul><li>The Diesel Intake Air Flow Control System (DIAFCS) motor/control may have failed, preventing proper operation.</li><li>An open circuit in the signal path to the DIAFCS motor/control can disrupt communication and cause the system to be stuck closed.</li><li>A short to voltage in the signal circuit to the DIAFCS motor/control can lead to incorrect signals being sent, resulting in malfunction.</li><li>A short to ground in the signal circuit to the DIAFCS motor/control can cause the system to fail by grounding out the signal.</li><li>Although less likely, a failed Powertrain Control Module (PCM) could also be responsible for this error code.</li></ul>

<ul> <li><b>Check Technical Service Bulletins (TSB)</b>: Verify if there are any TSBs related to the P02E5 code for your vehicle. This can provide known fixes and save diagnostic time.</li> <li><b>Locate DIAFCS Motor/Control System</b>: Find the Diesel Intake Air Flow Control System (DIAFCS) motor/control, typically attached to the intake manifold in the intake air stream.</li> <li><b>Visual Inspection of Connector and Wiring</b>: Inspect the connector and wiring for damage such as scraping, rubbing, bare wires, burn spots, or melted plastic. Check the terminals for burns or corrosion.</li> <li><b>Clean Terminals</b>: Use electrical contact cleaner and a plastic bristle brush to clean the terminals if needed. Let them dry and apply electrical grease to the contact points.</li> <li><b>Clean Carbon Deposits</b>: 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. Do not spray cleaner directly into the engine.</li> <li><b>Clear Diagnostic Trouble Codes</b>: Use a scan tool to clear the DTCs from memory. Check if the P02E5 code returns. If it does not, the issue was likely with the connections.</li> <li><b>Test DIAFCS and Circuits</b>: With the Key Off, disconnect the electrical connector at the DIAFCS motor/control. Use a Digital Voltmeter to check for 12 volts at the motor terminal with the Key On Engine Off. If voltage is incorrect, repair the power or ground wire, or replace the PCM.</li> <li><b>Replace DIAFCS Motor/Control</b>: If the previous tests passed and the P02E5 code persists, replace the DIAFCS motor/control. Note that a failed PCM cannot be ruled out until the DIAFCS motor/control is replaced.</li></ul>

<p>The DTC code P02E5 indicates that the Diesel Intake Air Flow Control is stuck closed. This issue is generally <b>not severe</b>. If mechanical issues are the cause, it typically results in <b>low idle speed</b>. In the case of an electrical failure, the PCM can usually compensate adequately. Immediate actions should include checking the intake air flow control mechanism and ensuring it is free of obstructions.</p>