Archives: DTC Codes

What Does Code P1783 Mean? DTC P1783 signifies that the Powertrain Control Module (PCM) or Transmission Control Module (TCM), depending on vehicle architecture, has detected an excessive transmission fluid temperature condition. The automatic transmission’s fluid temperature (TFT) sensor, typically an NTC (Negative Temperature Coefficient) thermistor, provides real-time temperature data to the control module. The PCM/TCM […]

What Does Code P1784 Mean? DTC P1784, which translates to “Transmission Mechanical Failure – First And Reverse,” indicates that the Powertrain Control Module (PCM) or Transmission Control Module (TCM) has detected an internal mechanical fault within the automatic transmission specifically affecting the engagement or operation of first gear and reverse gear. The TCM continuously monitors […]

What Does Code P1785 Mean? DTC P1785 signifies a mechanical failure within the automatic transmission specifically affecting the engagement or operation of first and second gears. The Powertrain Control Module (PCM), which often integrates the Transmission Control Module (TCM) functionality, monitors various operational parameters including input shaft speed, output shaft speed, and hydraulic pressure to […]

What Does Code P1786 Mean? DTC P1786 indicates a malfunction within the transmission’s 3-2 downshift circuit or hydraulic system, meaning the Powertrain Control Module (PCM), or Transmission Control Module (TCM) if separate, has detected an error when attempting to downshift the transmission from third gear to second gear. The PCM/TCM monitors various parameters, including input […]

What Does Code P1787 Mean? Diagnostic Trouble Code P1787 signifies a “2-1 Downshift Error” within the automatic transmission control system. This code is typically set by the Transmission Control Module (TCM) or Powertrain Control Module (PCM), which monitors and manages all aspects of transmission operation. Specifically, P1787 indicates that the module has detected an anomaly […]

What Does Code P1788 Mean? DTC P1788 indicates an Open Circuit condition detected in the circuit of the Pressure Control Solenoid “B” within an automatic transmission. The Powertrain Control Module (PCM) or Transmission Control Module (TCM), often integrated, is responsible for monitoring and controlling various transmission functions, including line pressure regulation. Pressure Control Solenoids (PCS) […]

What Does Code P1789 Mean? DTC P1789 indicates that the Powertrain Control Module (PCM) or Transmission Control Module (TCM) has detected an electrical short circuit within the circuit of the Pressure Control Solenoid “B”. Pressure Control Solenoids, also frequently referred to as Electronic Pressure Control (EPC) solenoids, are crucial components within the automatic transmission’s valve […]

What Does Code P1790 Mean? The diagnostic trouble code P1790 indicates a malfunction within the Throttle Position (TP) mechanical circuit. This code is generated by the Engine Control Module (ECM) or Powertrain Control Module (PCM) when it detects an inconsistency or abnormal behavior in the throttle position sensor (TPS) signal that points towards a mechanical […]

What Does Code P1791 Mean? DTC P1791 signifies a detected malfunction within the Throttle Position (TP) Electric Circuit. This code is set by the Engine Control Module (ECM), also known as the Powertrain Control Module (PCM), when it identifies an out-of-specification electrical signal from the throttle position sensor. The TP sensor is a crucial component […]

What Does Code P1792 Mean? The diagnostic trouble code P1792 indicates a malfunction within the Barometric Pressure (BARO) sensor circuit. The Engine Control Module (ECM), also known as the Powertrain Control Module (PCM), relies on the BARO sensor to measure atmospheric pressure. This crucial data allows the ECM to calculate and adjust engine operating parameters […]