Transaxle Definitions and Abbreviations

TRANSAXLE DEFINITIONS AND ABBREVIATIONS
The following definitions and abbreviations are provided to establish a common language for describing transaxle-related conditions. These terms are used in the transaxle section of this manual.


Throttle Positions
- Minimum Throttle - the least amount of throttle opening required for an upshift.
- Light Throttle - approximately 1/4 of accelerator pedal travel (25% throttle position).
- Medium Throttle - approximately 1/2 of accelerator pedal travel (50% throttle position).
- Heavy Throttle - approximately 3/4 of accelerator pedal travel (75) throttle position).
- Wide Open Throttle (WOT) - full travel of the accelerator pedal (100% throttle position).
- Full Throttle Detent Downshift - a quick apply of the accelerator pedal to its full travel, forcing a downshift.
- Zero Throttle Coastdown - a full release of the accelerator pedal while the car is in motion and in drive range. ,
- Engine Braking - a condition where the engine is used to slow the car by manually downshifting during a zero throttle coastdown.


Shift Conditions
- Bump - a sudden and forceful apply of a clutch or band.
- Chuggle - a bucking or jerking that may be most noticeable when the converter clutch is engaged; similar to the feel of towing a trailer.
- Delayed - a condition where a shift is expected but does not occur for a period of time. Samples of this could be described as clutch or band engagement that does not occur as quickly as expected during a part throttle or wide open throttle apply of the accelerator or, when manually downshifting to a lower range. Also defined as "LATE" or"EXTENDED."
- Double Bump (Double Feel) - two sudden and forceful applies of a clutch or band.
- Early - a condition where the shift occurs before the car has reached proper speed. Tends to labor the engine after the upshift.
- End Bump - a firmer feel at the end of a shift as compared to the feel at the start of the shift. Also defined as "END FEEL" or"SLIP BUMP."
- Firm - a noticeably quick apply of a clutch or band that is considered normal with a medium to heavy throttle. Should not be confused with "HARSH" or "ROUGH."
- Flare - a quick increase in engine RPM along with a momentary loss of torque. This most generally occurs during a shift. Also defined as "SLIPPING."
- Harsh (Rough) - a more noticeable apply of a clutch or band as compared with "FIRM." This condition is considered undesirable at any throttle position.
- Hunting - a repeating quick series of upshifts and downshifts that causes a noticeable change in engine RPM. An example could be described as a 4-3-4 shift pattern. Also defined as "BUSYNESS."
- Initial Feel - a distinct firmer feel at the start of a shift as compared to the finish of the shift.
- Late - a shift that occurs when the engine is at a higher than normal RPM for a given amount of throttle.
- Shudder - a repeating jerking condition similar to "CHUGGLE" but more severe and rapid. This condition may be most noticeable during certain ranges of car speed.
- Slipping - a noticeable increase in engine RPM without a car speed increase. A slip usually occurs during or after initial clutch or band apply.
- Soft - a slow, almost unnoticeable clutch or band apply with very little shift feel.
- Surge - a repeating engine related condition of acceleration and deceleration that is less intense than "CHUGGLE."
- Tie-Up - a condition where two opposing clutches and/or bands are attempting to apply at the same time causing the engine to labor with a noticeable loss of engine RPM.


Noise Conditions
- Drive Link Noise - a whine or growl that increases or fades with engine RPM. Noise is not noticeable under light throttle acceleration or in "DRIVE" or "REVERSE" with the car stationary.
- Final Drive Noise - a hum related to car speed and is most noticeable under light throttle acceleration or zero throttle coast down.
- Planetary Gear Noise - a whine, most noticeable in first gear and reverse that is related to vehicle speed. A gear noise condition may become less noticeable or go away after an upshift.
- Pump Noise - a high pitch whine that increases intensity with engine RPM. This condition may also be noticeable in ALL operating ranges.
- Torque Converter - a whine usually noticed when a vehicle is stopped and transaxle is in "DRIVE" or "REVERSE." The noise will increase with engine RPM. See Torque Converter Evaluation for further information.


Abbreviations
- PCM - Powertrain Control Module
- TCC Sol. Valve - Torque Converter Clutch Solenoid Valve
- TP Sensor - Throttle Position Sensor
- ECT Sensor - Engine Coolant Temperature Sensor
- A/T VSS Sensor - Automatic Transmission Vehicle Speed Sensor
- A/T ISS - Automatic Transmission Input Shaft Speed Sensor
- NC- Normally Closed
- NO - Normally Open
- PC Solenoid - Pressure Control Solenoid
- TR - Transaxle Range Selector Switch
- PWM - Pulse Width Modulated
- WOT - Wide Open Throttle
- RPM - Revolutions Per Minute
- PM - Permanent Magnet
- A/C - Air Conditioning
- MAP - Manifold Absolute Pressure
- TFT - Transmission Fluid Temperature (Sensor)
- AC - Alternating Current
- DC - Direct Current
- CKT - Circuit
- DTC - Diagnostic Trouble Code
- DVM - Digital Volt Meter
- OBD - On Board Diagnostics
- DLC - Data Link Connector
- EGR - Exhaust Gas Recirculation