What is the reason for the fault code appearing in Dongfeng Tianlong?
2 Answers
Dongfeng Tianlong's fault code indicates that the electronic control unit could not detect the signal from the B camshaft position sensor within the set time period. The following is a detailed introduction to the camshaft sensor: 1. Function: The camshaft sensor transmits the operational status of the cylinders to the ECU (electronic control unit) to enable sequential fuel injection control, ignition timing control, and knock control. If the vehicle exhibits symptoms such as difficulty starting, unstable idling, engine shaking, poor acceleration, increased fuel consumption, or a continuously illuminated fault light, it indicates a malfunction in the camshaft sensor. 2. Working Principle: The camshaft position sensor detects the position and angle of the camshaft to determine the top dead center position of the first cylinder piston during compression. During startup, the engine ECU uses signals from the camshaft position sensor and the crankshaft position sensor to identify the position and stroke of each cylinder piston, controlling the fuel injection sequence and ignition sequence for precise fuel injection and ignition control.
That fault code lighting up is really annoying! My Dongfeng Tianlong kept showing SCR system fault codes during long-distance trips last year. It turned out to be clogged urea nozzles due to scaling. These types of faults usually fall into several possibilities: emission-related issues are most common, including abnormal urea injection or DPF clogging; next are sensor problems, like faulty NOx sensors or exhaust temperature sensors causing false alarms; there could also be oxidized or loose wiring connectors. I recommend first connecting a diagnostic tool to read the specific code. If it shows something like P204F (urea injection fault), prioritize checking urea solution concentration and nozzle carbon buildup. The electrical connectors on trucks are quite prone to moisture – last time the service technician just sprayed some electronic cleaner on the wiring harness connectors and it fixed the issue.
