A common trouble code for International trucks is 163, which indicates “exhaust gas recirculation valve position signal out-of-range - low.” This code frequently leads to the 312 high-oil temperature code and the 322 and 323 high engine coolant temperature codes. The vehicle’s computer triggers the 163 code when it can no longer detect a signal from the sensor that monitors the engine’s EGR intake valve.
The code generally appears when the valve becomes stuck in an open or closed position. The valve may become stuck due to the accumulation of soot and carbon deposits from the exhaust gases, or by the accumulation of heat raising the surface temperature of the engine to a point at which the valve remains closed, which prevents the exhaust gas from re-entering the ignition chamber.
The 161 trouble code deserves immediate attention. Early detection of a clogged valve may allow the owner to resolve the problem by cleaning the valve rather than replacing it. Prolonged exposure to high engine temperatures can cause further damage to the valve, seals and other vital engine parts. In addition, exhaust gases contain unconsumed fuel. Recirculation of these gases enables the engine to operate at a lower temperature, which reduces carbon emissions. Failure to address a problem with the EGR system results in exhaust gas that causes the vehicle to fail emission tests.