What Causes the Engine Warning Light to Illuminate in the Roewe RX5?
2 Answers
The engine warning light may illuminate due to the following 7 main reasons: Sensor Malfunction: Sensors such as coolant temperature, crankshaft position, air flow, intake temperature, and oxygen sensors can trigger the warning light if they are damaged, have poor connections, or signal interruptions. This prevents the ECU from accurately obtaining engine data. Fuel or Oil Quality Issues: Using fuel or engine oil that does not meet the manufacturer's specifications may cause engine wear, leading to the warning light. Poor Combustion of Air-Fuel Mixture: Incomplete combustion can result in engine carbon buildup or knocking. The oxygen sensor detects this and reports it to the ECU, triggering the warning light. Causes include faulty spark plugs, ignition coils, fuel pumps, or clogged fuel lines. Turbocharger Problems: Issues with the intake boost system or turbocharger (e.g., leaks, excessive oil consumption, power loss, unusual metal noises, or blue/black exhaust smoke) can activate the warning light. Air Intake Problems: Blockages in the engine intake system, often due to a dirty air filter, can cause the warning light to illuminate. Exhaust System Faults: Malfunctions in components like the rear oxygen sensor, catalytic converter, or exhaust camshaft (often caused by leaded fuel, improper additives, physical damage, or fuel system issues) may trigger the warning light. Anti-Theft System Failure: A malfunctioning electronic anti-theft system or mismatched controllers can prevent the engine from operating normally and activate the warning light. Steps to Address the Engine Warning Light: 1. Check if the engine runs abnormally (e.g., shaking, smoke). If so, avoid restarting—especially if the light is red. 2. If the engine starts, turn it off for 5-10 minutes, then power on the vehicle (without pressing brakes/clutch) to initiate a self-check. Observe if the light turns off after 5-10 seconds. 3. If the light persists, visit a service center promptly for diagnostics and targeted repairs using a portable scanner to read fault codes.
I've fixed quite a few of these issues. The most common causes for the engine light in Roewe RX5 are problems with the catalytic converter or oxygen sensors. Especially if you've been refueling at small gas stations for a long time, the catalytic converter can easily get clogged, and you'll hear a chugging sound from the exhaust pipe. Another possibility is an air leak in the intake system or a dirty throttle body - when the ECU can't detect normal air intake, it triggers a warning. Last time, there was a car whose warning light kept flickering on and off, and it turned out to be caused by poor fuel quality leading to incomplete combustion. Issues with knock sensors and camshaft position sensors aren't uncommon either, especially in older vehicles. Oh, and even something as simple as a loose fuel cap can inexplicably trigger the light. Reading the trouble codes is key - I recommend using an OBD scanner to check the codes first before proceeding with targeted repairs.
