CIRCUIT DESCRIPTION:SEM allows the TCM to request torque reduction from the engine controller. Reducing torque allows quicker shifts with more consistent output torque and reduces clutch temperatures which increases clutch life. When an engine torque rating exceeds certain limits, LRTP is used. This feature limits engine torque in lower ranges to protect the transmission from damage if a stall condition occurs. ACTION TAKEN WHEN THE DTC SETS:1. The CHECK TRANS light illuminates.2. If the TCM and ECM software are not compatible, the transmission is restricted to reverse, neutral, and 3rd range.3. The TCM forces Variable Modulated Main off.4. The TCM...

CIRCUIT DESCRIPTION:The TCM is equipped with an internal temperature sensor mounted directly to its circuit board. The TCM will take action to protect against damage from overheat. ACTION TAKEN WHEN THE DTC SETS:1. The TCM illuminates the CHECK TRANS light (non-OBD II strategy).2. The TCM commands OFF all solenoids (SOLOFF).3. The TCM forces Variable Modulated Main off.4. The transmission will default to hydraulic state of Neutral, Reverse, 1st, 3rd, 5th.5. DTC is stored in the TCM history. CONDITIONS FOR CLEARING THE DTC:Use the diagnostic tool to clear the DTC from the TCM history. The TCM automatically clears the DTC from...

CIRCUIT DESCRIPTION:The sensor reference voltage diagnostic checks the integrity of the 5 volt reference used to power all of the analog input sensors such as Transmission Fluid Temperature (TFT), Throttle Position Sensor (TPS), and the 6-speed Three-Position switch Interface circuits. DTC P0642 is set when a 5 volt reference circuit voltage is below a calibration voltage for a calibration time period. ACTION TAKEN WHEN THE DTC SETS:When DTC P0642 is active, the following conditions occur:1. The CHECK TRANS light is illuminated.2. DTC is stored in TCM history.3. Additional DTCs active depending on 5V reference to function normally. CONDITIONS FOR CLEARING...

CIRCUIT DESCRIPTION:The sensor reference voltage diagnostic checks the integrity of the 5 volt reference used to power all of the analog input sensors such as oil temperature, Throttle Position Sensor (TPS), and the 6-speed Three-Position interface circuits. DTC P0643 is set when a 5 volt reference circuit voltage is above a calibrated voltage for a calibrated time period. ACTION TAKEN WHEN THE DTC SETS:When DTC P0643 is active, the following conditions occur:1. The CHECK TRANS light is illuminated.2. DTC is stored in TCM history.3. Additional DTCs active depending on 5V reference to function normally. CONDITIONS FOR CLEARING DTC/CHECK TRANS LIGHT:Use...

CIRCUIT DESCRIPTION:High Side Driver 1 (HSD1) supplies battery voltage to the Main Modulation, Torque Converter Clutch (TCC) and Pressure Control Solenoid 1 (PCS1) solenoids via wire 111. HSD1 is continuously on during normal operation except during brief circuit tests. The TCM regulates control current to the solenoids by switching the appropriate low side driver on and off. DTC P0657 indicates the TCM has detected multiple low side circuits are open while having HSD1 voltage. DTC P0657 could be caused by open condition in the high side wiring attached to HSD1 (wire 111). ACTION TAKEN WHEN THE DTC SETS:1. Main modulation...