Scan Tool Output Control
| Additional Menu Selections
| Description
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PC Solenoid
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| • | The PCM commands the amperage, current, to the pressure control solenoid in order to control transmission line pressure. As the amperage increases, the line pressure decreases. As the amperage decreases, the line pressure increases. |
| • | When the ignition is ON, and the engine is OFF, the reference, commanded, amperage may be controlled within calibrated limits. The scan tool parameter "PC Sol. Ref. Current" changes but the parameter "PC Sol. Actual Current"
does not change. The reference current remains until commanded otherwise. |
| • | When the engine is running, the following control limits apply: |
| - | When the transmission range is Park or Neutral, the reference, commanded, amperage may be controlled within calibrated limits. The engine speed must be less than 1,500 RPM. If the engine speed is greater than 1,500 RPM, the message "TR
in park/neutral and engine speed over 1,500 RPM" appears on the scan tool display. Both the scan tool parameters "PC Sol. Ref. Current" and "PC Sol. Actual Current" change. Both current readings remain until commanded otherwise. |
| - | When the transmission range is not in Park or Neutral, the reference amperage can only be controlled less than the current determined by the PCM. The PCM does not allow a value to be selected that may cause damage to the transmission. If the requested
amperage is more than allowed by the PCM, the message "Requested current for the PC Solenoid is too high" appears on the scan tool display. |
| - | Transmission range DTCs must not be active. If a transmission range DTC is active, the message "Engine running with transmission DTC present" appears on the scan tool display. |
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Shift Transmission
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| • | The PCM commands upshifts and downshifts. The scan tool Commanded Gear parameter should correspond with the shift solenoid combination. |
| • | When the ignition is ON, and the engine is OFF, there are no limits to this control. The scan tool shift solenoid states change to match the Commanded Gear selected. |
| • | When the engine is running, the following control limits apply: |
| - | The PCM does not allow a shift if it causes the engine RPM to exceed a calibrated limit. If a gear is requested and the engine speed is too high, the message "Engine speed too high" appears on the scan tool display. |
| - | The PCM does not allow a 3-2 or 2-1 downshift if the vehicle speed exceeds a calibrated limit. If either downshift is requested and the vehicle speed is too high, the message "Eng. is on and veh. speed too hi for 3-2 or 2-1
downshift" appears on the scan tool display. |
| - | The PCM does not allow a 4-3 downshift if the vehicle speed exceeds a calibrated limit. If a 4-3 downshift is requested and the vehicle speed is too high, the message "Vehicle speed too high" appears on the scan tool display. |
| - | The PCM does not allow an upshift if the vehicle speed exceeds a calibrated limit. If an upshift is requested and the vehicle speed is too high, the message "Vehicle speed too high" appears on the scan tool display. |
| - | The PCM does not allow an upshift that is greater than the current selected transmission range (PRNDL). For example 3rd gear is not allowed if the transmission range is D2. If an upshift is requested that is greater than the current selected transmission
range, the message "Eng. running and gear request is greater than the current TR" appears on the scan tool display. |
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TCC Control Solenoid
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| • | The PCM commands the duty cycle of the TCC PWM solenoid. The duty cycle is represented by a percentage of ON, energized, time. Approximately 90-100 percent duty cycle represents an ON, energized, commanded state. Zero percent represents
an OFF, non-energized, commanded state. The scan tool TCC Duty Cycle parameter should match the commanded state. |
| • | When the ignition is ON, and the engine is OFF, there are no limits to this control. The solenoid remains ON, 90-100 percent duty cycle, until commanded OFF, zero percent duty cycle, and vice versa. When the output control is exited, the solenoid
duty cycle is determined by the PCM. |
| • | The PCM commands the TCC enable solenoid valve ON and OFF. The scan tool TCC Enable parameter should match the commanded state. |
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