U1503 Engine Trouble Code

Meaning of U1503 engine trouble code is a kind of network trouble code and when your car's 'U1503 Check Engine' light comes on, it's usually accompanied by a sinking feeling in the pit of your stomach. The light could mean a costly problem, like a bad catalytic converter, or it could be something minor, like a loose gas cap. But in many cases, it means at minimum that you'll be visiting the car dealer to locate the malfunction and get the light turned off.

U1503 Fault Symptoms :

U1503 Possible Solution:

Gasoline engines use spark plugs to cause an explosion of fuel within the cylinder. In a properly timed engine, this explosion occurs at the proper moment to send the piston to the bottom of the cylinder and provide power to the drive shaft. If the plug wires are out of sequence, the explosion occurs at the wrong time. The improper timing of the explosion sometimes pushes the cylinder the wrong direction or interferes with the turning of the crank. As a result, the engine stutters or backfires, if it runs at all.

U1503 Code Meaning :

Is the fuel pump sometimes not priming when you turn the key to ON(II)? Start by measuring the fuel pressure and checking whether you have bright white-bluish spark at all four plugs. The mechanical timing is also something that you should check, as we mentioned above.

U1503 DTC specifically refers to the camshaft (cam) timing. In this case, if the cam timing is over-retarded, the engine light will be illluminated and the code will be set.