Medium and Heavy Trucks
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Hi AJ, My name is***** with me while I Pull up those codes.
123 Intake Manifold Pressure Sensor Circuit
268 Fuel Pressure Sensor Circuit
-ECM software updates needed
-Faulty pressure sensor or harness
-Poor ECM grounds
452 Fuel Pressure Sensor Circuit
Low voltage at the pressure/temperature sensor . check connector pin 46 for corrosion or poor connections at the rear of the accumulator.
123 is low voltage detected at signal pin 45 from the ECM for the boost pressure sensor. Check the ECM power and grounds and verify the ECM has sufficient power and ground and the batteries and charging system test good as well as all connections between the batteries and starter. Let me know