Car DTC means: Diagnostic Trouble Code (DTC). ?Inspection to determine the technical condition of the car and identify the fault location and cause without dismantling it (or only removing individual parts).
Including the detection and diagnosis of automobile engines, the detection and diagnosis of automobile chassis, the detection and diagnosis of automobile bodies and accessories, and the detection of automobile exhaust pollutants and noise.
According to the requirements of OBDII, the diagnostic execution command divides the fault code DTC into different types according to factors such as the monitoring system and the severity of the fault. Different types also have different requirements for the set code.
The diagnostic execution command only causes the engine malfunction light MIL to illuminate when an emission-related DTC occurs (which may exceed 1.5 times the FTP regulations). DTC is divided into four major categories, including A.B.C and D. Among them, the DTCs of Category A and B are related to the emission level of the engine.
Extended information:
DTC is divided into four categories, including A.B.C and D. Among them, the DTCs of A and B are related to the emission level of the engine.
Category A: Perform diagnostic monitoring during the first trip, report "fault detected" to the diagnostic execution command, store the DTC and light the MIL light.
Category B: Runs diagnostic tests related to emission levels on the first consecutive trip and reports "fault detected" to the diagnostic command, stores the DTC and lights the MIL. After a fault is detected for the first time, the Class B fault code will enter preparation. After that, the Class B fault code will be in an alert state or prepare to store a historical code.
If this fault occurs again, the MIL will be illuminated; otherwise, a passed detection will relieve the system from the alert state of Class B DTC. Some special conditions will be used for misfire and fuel trim DTC fault codes.
Category C: Run non-emission-related diagnostic tests on the first trip, report "Failure Detected" to the diagnostic execution command at the same time, store the DTC while turning on the vehicle service light "SERVICE VEHICLE SOON"
If equipped) lights up.
Category D: Run non-emission-related diagnostic tests on the first trip and report to the diagnostic execution command. "Fault detected", Class D will store DTC without lighting the MIL light. These fault code DTCs will be very helpful for maintenance and diagnosis of the vehicle, especially when the driver points out some performance degradation and the MIL is not lit. .
Automotive Technical Maintenance Network-What is the fault of DTC