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Reason:Accelerator Pedal or Lever Idle Validation Switch – Received Network Data In Error. The J1939 multiplexing controller has indicated a malfunction of the accelerator pedal or lever idle validation switch Effect:Engine will only idle. Circuit Description:Normally, switches, accelerators, and other components are connected to the engine control module (ECM) directly through individual wires. Multiplexing allows those same components to be hard wired to an original equipment manufacturer (OEM) vehicle electronic control unit (VECU) or transmission electronic control unit (ECU) in the cab. Then component values and states from components such as sensors, accelerators, and switches can be transmitted from the...

Reason:Accelerator Pedal or Lever Idle Validation Switch – Abnormal Update Rate. No communication or an invalid data transfer rate has been detected on the J1939 data link between the ECM and the accelerator pedal or lever idle validation switch. Effect:Engine will only idle. Circuit Description:Normally, switches, accelerators, and other components are connected to the engine control module (ECM) directly through individual wires. Multiplexing allows those same components to be hard wired to an original equipment manufacturer (OEM) vehicle electronic control unit (VECU) or transmission electronic control unit (ECU) in the cab. Then component values and states from components such as...

Reason:Engine Intake Throttle Actuator Position Sensor Circuit – Voltage above normal, or shorted to high source. High signal voltage detected at the engine intake air throttle position sensor circuit. Effect:Possible reduced engine performance. Circuit Description:The engine control module (ECM) controls the engine intake air throttle actuator. The ECM can open and close the throttle based on the operating condtions in order to regulate air flow to the engine. Component Location:The engine intake air throttle actuator is mounted in the piping between the charge air cooler and intake manifold. Conditions for Running the Diagnostics:This diagnostic runs continuously when the keyswitch is...

Reason:Engine Intake Throttle Actuator Position Sensor Circuit – Voltage below normal, or shorted to low source. Low signal voltage detected at the engine intake air throttle position sensor circuit. Effect:Possible reduced engine performance Circuit Description:The engine control module (ECM) controls the engine intake air throttle actuator. The ECM can open and close the throttle based on the operating condtions in order to regulate air flow to the engine. Component Location:The engine intake air throttle actuator is mounted in the piping between the charge air cooler and intake manifold. Conditions for Running the Diagnostics:This diagnostic runs continuously when the keyswitch is...

Reason:NOx Limits Exceeded Due to Insufficient Reagent Quality – Condition Exists. The diesel exhaust fluid quality is not sufficient enough to provide adequate NOx reduction. Effect:Possible reduced engine performance. Circuit Description:The engine control module (ECM) monitors the NOx concentration in the engine’s exhaust gases using an aftertreatment intake NOx sensor and an aftertreatment outlet NOx sensor. By comparing these two values, the ECM is able to determine the conversion efficiency of the SCR catalyst and dosing system. Component Location:The SCR catalyst is located in the vehicle’s exhaust system, after the diesel particulate filter and decomposition tube. Conditions for Running the...