Scan Tool Output Control
| Additional Menu Selections
| Description
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Shift Solenoids C, D, and E
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| • | The TCM commands the shift solenoid ON and OFF. The scan tool solenoid parameter should match the commanded state. The scan tool Commanded Gear parameter should correspond with the shift solenoid combination. Refer to
Solenoid and Clutch Chart. |
| • | When the ignition is ON, and the engine is OFF, there are no limits to this control. The solenoid remains ON until commanded OFF, and vice versa. When the output control is exited, the solenoid state is determined by the TCM. |
| • | When the engine is running, the following control limits apply: |
| - | Only sequential gear changes are allowed. For example, 1st to 3rd is not allowed. If a non-sequential gear change is attempted, the message "Non-sequential gear changes not allowed. Gear changes must be in order" appears on the scan tool display. |
| - | The vehicle speed must be below a calibrated value. If the vehicle speed is too high, the message "Vehicle speed too high" appears on the scan tool display. |
| - | The engine speed must be below a calibrated value. If the engine speed is too high, the message "Engine speed too high" appears on the scan tool display. |
| - | Downshifts are allowed only when the vehicle speed is below a calibrated value. If 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 gear requested may not be greater than the current selected transmission range, PRNDL. For example, 3rd gear is not allowed if the transmission range is D2. If the gear requested 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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Clear TAP (Transmission Adaptive Pressures)
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| • | Allows the TCM to reset, the TAP cells to the original base value on individual shifts. |
| • | There are no limits to using this output control. It may be performed with the engine running or when the ignition is ON, and the engine is OFF. |
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Clear ALL TAP Cells (Transmission Adaptive Pressures)
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| • | Allows the TCM to reset, the TAP cells to the original base value for all shifts. |
| • | There are no limits to using this output control. It may be performed with the engine running or when the ignition is ON, and the engine is OFF. |
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PC Solenoid A and B
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| • | The TCM 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. The amperage
range is 0.00-1.10 and may be commanded in one-tenth amp increments. |
| • | 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 900 RPM. If the engine speed is greater than 900 RPM, the message "TR in park/neutral
and engine speed over 900 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 TCM. The TCM 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 TCM, 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 TCM commands upshifts and downshifts. The scan tool Commanded Gear parameter should correspond with the shift solenoid combination. Refer to
Solenoid and Clutch Chart. |
| • | 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 TCM 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 TCM does not allow a downshift if the vehicle speed exceeds a calibrated limit. If a downshift is requested and the vehicle speed is too high, the message "Eng. is on and veh. speed too hi for downshift" appears on the scan tool display. |
| - | The TCM 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 TCM 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 TCM 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 TCM. |
| • | When the engine is running, the following control limits apply: |
| - | If the transmission range is Park, and the transmission is in hot mode, the TCC control solenoid may not be commanded OFF. If the solenoid is requested OFF, the message "TCC OFF command disabled in Hot Mode" appears on the scan tool display. |
| - | The TCC control solenoid may not be commanded OFF for more than a calibrated amount of time. If the solenoid is commanded OFF, for a certain amount of time, the message "TCC OFF time has been exceeded" appears on the scan tool display. |
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Fast Learn Adapt Process
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| • | When the ignition is ON and engine is OFF, there are no limits to this control. |
| • | FastLearn is a procedure for which a series of test are run to allow the transmission control module (TCM) to learn individual clutch characteristics. Once the clutch data is learned, FastLearn translates it to the adaptive data cells, which the
TCM uses for clutch control during range shifts. Refer to
FastLearn Procedure. |
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Preselect All TAP Cells (Transmission Adaptive Pressures)
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| • | Allows the TCM to reset, the TAP cells to the original base value on individual shifts. |
| • | There are no limits to using this output control. It may be performed with the engine running or when the ignition is ON, and the engine is OFF. |
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