U0251 Daihatsu D-Compact is described as Intake Air Temperature (IAT) Circuit Malfunction. It's actually a general trouble code for a problem on IAT electrical circuit sensor, as it sends incorrect voltage input signals to the PCM. This is because the barometric pressure sensor is part of the MAF sensor. Sometimes, the MAF's sensing wire can accumulate and get covered with dirt, dust and/or oil residue, which can also lead to the error code.
SymptomsSymptoms of a U0251 Daihatsu D-Compact diagnostic trouble code may include:
Possible Causes :
If all testing has passed so far yet you still have the same code, check your scan tool and see if it can open and close the IMRC valve. Look for missing ground strap or a rusty ground where the fuel tank is grounded to the frame. Check for damage to the wiring harness connector.
Diagnostic trouble code U0251 Daihatsu D-Compact is not difficult to diagnose and repair. Thus, it always pays to have a qualified technician to look after your vehicle should this error code arise.
Diagnosing this code requires the engine to be in good running shape, without unmetered air entering the engine. If other codes that relates to misfiring condition, lean running or air entering the engine is present, then you must first fix those error codes before U0251 Daihatsu D-Compact.
Fortunately, U0251 Daihatsu D-Compact is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.