The meaning of the engine U1098 Code is important thing and it is important thing. The automobile meaning of the code is U for Network Code Problem is climate control system, lighting, airbags, etc. 1 for MFG – Manufacturer Specific. 0 for Fuel And Air Metering. 9 for Crankshaft Position Sensor Circuit Performance and 8 for PCM Stack Overrun. Alike the all car engines, this engine system employs specially developed hydraulic lifters what is known as switching roller followers for the engine U1098 code intake and finish valves. The lifters can be warped by disengaging an inner locking pin. The locking pin is disconnected using solenoids to modify oil compression fed into the lifter.