Throttle Positions

Engine Braking: A condition where the engine is used to slow the vehicle by manually downshifting during a zero throttle coastdown.

Full Throttle Detent Downshift: A quick apply of the accelerator pedal to its full travel, forcing a downshift.

Heavy Throttle: Approximately 3/4 of accelerator pedal travel, 75 percent throttle position.

Light Throttle: Approximately 1/4 of accelerator pedal travel, 25 percent throttle position.

Medium Throttle: Approximately 1/2 of accelerator pedal travel, 50 percent throttle position.

Minimum Throttle: The least amount of throttle opening required for an upshift.

Wide Open Throttle (WOT): Full travel of the accelerator pedal, 100 percent throttle position.

Zero Throttle Coastdown: A full release of the accelerator pedal while the vehicle is in motion and in drive range.

Zero Throttle Brake Applied: Regenative Braking is when the rear wheels are driving the drive motor (w/generator) 2nd position and producing power to be put back in the ESS.

Shift Condition Definitions

Bump: A sudden and forceful apply of a clutch.

Chuggle: A bucking or jerking. It is 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. This could be described as a clutch engagement that does not occur as quickly as expected during a part throttle or wide open throttle apply of the accelerator, or during manual downshifting to a lower range. This term is also defined as LATE or EXTENDED.

Double Bump - Double Feel: Two sudden and forceful applies of a clutch.

Early: A condition where the shift occurs before the vehicle has reached proper speed. This condition tends to labor the engine after the upshift.

End Bump: A firmer feel at the end of a shift than at the start of the shift. This is also defined as END FEEL or SLIP BUMP.

Firm: A noticeably quick apply of a clutch that is considered normal with a medium to heavy throttle. This apply 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. This condition is also defined as SLIPPING.

Harsh - Rough: A more noticeable apply of a clutch than 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, such as a 4-3-4 shift pattern. This condition is also defined as BUSYNESS.

Initial Feel: A distinctly firmer feel at the start of a shift than at the finish of the shift.

Late: A shift that occurs when the engine RPM is higher than normal 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 vehicle speed.

Slipping: A noticeable increase in engine RPM without a vehicle speed increase. A slip usually occurs during or after initial clutch apply.

Soft: A slow, almost unnoticeable clutch 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 clutchs 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 vehicle speed, and is most noticeable under a light throttle acceleration. It may also be noticeable in PARK or NEUTRAL operating ranges with the vehicle stationary.

Final Drive Noise: A hum related to vehicle speed which is most noticeable under a light throttle acceleration.

Planetary Gear Noise: A whine related to vehicle speed, which is most noticeable in FIRST gear, SECOND gear, FOURTH gear or REVERSE. The condition may become less noticeable, or go away, after an upshift.

Pump Noise: A high pitched whine that increases in intensity with engine RPM. This condition may also be noticeable in all operating ranges with the vehicle stationary or moving.

Driver Shift Control

Driver shift control (DSC) allows the driver to change gears similar to a manual transmission.

Transmission Abbreviations

A/C: Air Conditioning

AC: Alternating Current

APM: Accessorie DC Power Control Module

AT: Automatic Transmission

DC: Direct Current

DIC: Driver Information Center

DLC: Diagnostic Link Connector

DMM: Digital Multimeter

DSC:: Driver Shift Control

DTC: Diagnostic Trouble Code

ECT: Engine Coolant Temperature

EMI: Electromagnetic Interference

HPCM: Hybrid Powertrain Control Module

IAT: Intake Air Temperature

IGN: Ignition

IMS: Internal Mode Switch or Manual Shift Shaft Position Switch

MAP: Manifold Absolute Pressure

NC: Normally Closed

NO: Normally Open

OBD: On Board Diagnostic

OSS: Output Speed Sensor

PC: Pressure Control

PCM: Powertrain Control Module

PCS: Pressure Control Solenoid

PIM: Drive Motor Generator Power Inverter Control Module

PS: Pressure Switch

PWM: Pulse Width Modulation

RPM: Revolutions Per Minute

SS: Shift Solenoid

TAP: Transmission Adaptive Pressure

TCM: Transmission Control Module

TFP: Transmission Fluid Pressure

TFT: Transmission Fluid Temperature

THECM: Transmission Hydraulic Electronic Control Module

TP: Throttle Position

VSS: Vehicle Speed Sensor

WOT: Wide Open Throttle