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Reason:Engine Brake Actuator Driver 1 Circuit – Voltage Below Normal or Shorted to Low Source. Low voltage detected at the engine brake solenoid number 1 signal circuit. Effect:Possible reduce engine braking performance Circuit Description:The Engine Control Module (ECM) controls engine brakes on cylinders 1, 2, and 3 by sending a signal on the engine brake solenoid number 1 signal circuit. If an engine brake is installed, there will be a jumper harness from this connector to the engine brake pass-through connectors on the rocker lever housing. Component Location:The engine brake solenoids are located under the valve cover. The engine brake...

Reason:Sensor Supply 4 Circuit – Voltage Above Normal or Shorted to High Source. High voltage detected at 5 VDC sensor supply circuit to the accelerator pedal position sensor. Effect:Engine will only idle. Circuit Description:Sensor supply 4 of the engine control module (ECM) provides a 5 VDC supply to the accelerator pedal position sensor. Component Location:The accelerator pedal or lever position sensor is mounted to the accelerator pedal assembly. Refer to the OEM service manual. Conditions for Running the Diagnostics:This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running. Conditions for Setting the...

Reason:Sensor Supply 4 Circuit – Voltage Below Normal or Shorted to Low Source. Low voltage detected at the 5 VDC sensor supply circuit to the accelerator pedal position sensor. Effect:Engine will only idle. Circuit Description:Sensor supply 4 of the engine control module (ECM) provides a 5 VDC supply to the accelerator pedal position sensor. Component Location:The accelerator pedal or lever position sensor is mounted to the accelerator pedal assembly. Refer to the OEM service manual. Conditions for Running the Diagnostics:This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running. Conditions for Setting...

Reason:Barometric Pressure Sensor Circuit – Voltage Above Normal or Shorted to High Source. High signal voltage detected at barometric pressure circuit. Effect:Possible reduced engine performance. Circuit Description:The barometric pressure sensor responds to pressure changes in the atmospheric pressure. The pressure changes occur based on the elevation where the engine is presently operating. The barometric pressure sensor has a 5 volt supply circuit, a sensor signal voltage, and a return circuit. Component Location:The barometric pressure sensor is mounted on the main branch of the engine harness near the ECM. Conditions for Running the Diagnostics:This diagnostic runs continuously when the keyswitch is...

Reason:Barometric Pressure Sensor Circuit – Voltage Below Normal or Shorted to Low Source. Low signal voltage detected at barometric pressure circuit. Effect:Possible reduced engine performance. Circuit Description:The barometric pressure sensor responds to pressure changes in the atmospheric pressure. The pressure changes occur based on the elevation where the engine is presently operating. The barometric pressure sensor has a 5 volt supply circuit, a sensor signal voltage, and a return circuit. Component Location:The barometric pressure sensor is mounted on the main branch of the engine harness near the ECM. Conditions for Running the Diagnostics:This diagnostic runs continuously when the keyswitch is...