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Reason:Auxiliary PWM Driver 1 Circuit – Voltage Below Normal or Shorted to Low Source. Low signal voltage detected at the pulse width modulation (PWM) auxiliary circuit. Effect:Possible reduced engine performance. Circuit Description:The transmission shift modulator uses this signal from the electronic control module (ECM) to determine when to shift the transmission. The return circuit is dependent on original equipment manufacturer (OEM) wiring. It may be wired back to the ECM on some vehicles or wired to chassis or block ground on others. Consult the OEM wiring diagram for return circuit details. Component Location:Refer to the OEM wiring diagram for the...

Reason:Engine Charge Air Cooler Outlet Temperature – Voltage above normal, or shorted to high source Effect:None on performance Circuit Description:The electronic control module (ECM) uses the charge air cooler temperature sensor to measure the charge air cooler outlet temperature. The charge air cooler temperature sensor contains a variable resistor sensor and is used to measure the temperature of the air exiting the charge air cooler. The ECM supplies 5 volts to the charge air cooler temperature sensor signal circuit. The ECM monitors the change in voltage caused by changes in the resistance of the sensor to determine the temperature of...

Reason:Engine Charge Air Cooler Outlet Temperature – Voltage Below Normal or Shorted to Low Source. Effect:None on performance Circuit Description:The electronic control module (ECM) uses the charge air cooler temperature sensor to measure the charge air cooler outlet temperature. The charge air cooler temperature sensor contains a variable resistor sensor and is used to measure the temperature of the air exiting the charge air cooler. The ECM supplies 5 volts to the charge air cooler temperature sensor signal circuit. The ECM monitors the change in voltage caused by changes in the resistance of the sensor to determine the temperature of...

Reason:VGT Actuator Controller – Bad Intelligent Device or Component. An internal error has been detected by the smart VGT controller. Effort:Possible reduced engine performance. Circuit Description:The variable geometry turbocharger (VGT) is electronically activated by the VGT actuator. The VGT actuator is a smart device and receives information via the J1939 data link from the primary engine control module (ECM). The VGT actuator performs its own diagnostics and reports malfunctions back to the primary engine ECM, using the J1939 data link. The ECM then decodes the error message and converts it to a fault code. Component Location:The VGT actuator is located...

Reason:VGT Actuator Driver Circuit – Condition Exists. A calibration mismatch between the VGT actuator and the ECM has been detected. Effect:VGT actuation will be disabled Circuit Description:The variable geometry turbocharger (VGT) is electronically activated by the VGT actuator. The VGT actuator is a smart device and receives information via the J1939 data link from the primary engine control module (ECM). The VGT actuator performs its own diagnostics and reports malfunctions back to the primary engine ECM, using the J1939 data link. The ECM then decodes the error message and converts it to a fault code. Component Location:The VGT actuator is...