Where is the camshaft signal disc located on the 274 engine?
3 Answers
274 camshaft signal disc is located on the crankshaft flywheel. Below are the specific functions of the camshaft sensor: Ensure normal cylinder operation: Based on the cylinder's operating condition, the signal is transmitted to the ECU electronic control unit to perform sequential fuel injection control, ignition timing control, and knock control. Ensure accuracy of fuel injection and ignition: During startup, the engine ECU identifies the position and stroke of each cylinder piston based on signals from the camshaft position sensor and crankshaft position sensor, controlling the fuel injection sequence and ignition sequence for precise fuel injection and ignition control.
While studying the 274 engine, I found that the camshaft signal disc is typically located at the end or front of the camshaft, integrated into the camshaft position sensor unit. In the M274 engine, such as those in Mercedes-Benz models, the signal disc is installed in a more concealed position, near the camshaft pulley or gear, close to the cylinder head area. Its function is to provide precise signals of the camshaft's rotation to the ECU, controlling ignition and fuel injection timing. If the position is offset or the signal disc is worn, it can lead to engine starting difficulties, unstable idling, or even stalling, and in severe cases, cause knocking or lack of acceleration. Routine maintenance does not require direct contact with the signal disc, but once fault diagnostics show related codes, such as a camshaft position sensor error, it's best to have it checked at a professional shop to avoid minor issues turning into major repair costs. I've seen many owners neglect this signal disc, only to regret it when the engine's yellow warning light comes on.
As someone who frequently works on car repairs, I find the camshaft signal disc location quite straightforward when dealing with a 274 engine malfunction. After opening the engine compartment, the camshaft signal disc is mounted on a small circular plate, tightly secured to one end of the camwheel—typically near the belt drive area. Before starting work, it's advisable to disconnect the battery's negative terminal for safety. With basic tools, you can then access the sensor and signal disc assembly. If loose or dirty, this component may cause signal interruptions, manifesting as delayed starts or power hesitation. For maintenance, simply cleaning dust off the signal disc surface often resolves issues without major disassembly; however, severe damage requires replacement. Don't forget to inspect wiring harnesses for aging—prevention beats repair. Regular scans with an OBD diagnostic tool can proactively identify potential faults.
