Imagine you have removed the timing belt. You then rotate the camshafts to align their marks. Without the crankshaft locked at “top,” you have no reference. The crank may drift due to internal spring pressure from the piston rings. When you install the new belt and release the tensioner, you might be one or two teeth out of phase.
A massive library of fault codes with descriptions to help pinpoint issues during scanning. Timing Belt/Chain Instructions: autodata 348 top
Extensive libraries of fault codes with descriptions and suggested testing procedures. Critical Technical Considerations Imagine you have removed the timing belt