Adapt Function. Cadillac Concours 1997

For 1990-2009 cars

The 4T80-E transmission uses a line pressure control system, which has the ability to continuously adapt the system's line pressure. This compensates for normal wear of the following parts:

• | The clutch fiber plates

• | The seals

• | The springs

The PCM maintains the following adapt parameters for the transmission:

• | Upshift Adapt - The PCM monitors the Automatic Transmission Input(Shaft) Speed Sensor (A/T ISS) and the Vehicle Speed Sensor (VSS) during commanded shifts in order to determine if a shift is occurring too fast or too slow. The PCM adjusts the signal to the transmission pressure control solenoid valve in order to maintain a set shift feel.

• | Steady State Adapt - The PCM monitors the Automatic Transmission Input(Shaft) Speed Sensor (A/T ISS) and the Vehicle Speed Sensor (VSS) after a shift and the PCM calculates the amount of slippage in that gear. The PCM then adjusts the signal to the transmission pressure control solenoid valve in order to maintain slippage below a set amount.

• | Garage Shift Adapt - The PCM monitors the Automatic Transmission Input(Shaft) Speed Sensor (A/T ISS) during a shift into a given range (P,R,N,D) and the PCM calculates whether the engagement is occurring too fast or too slow. The PCM adjusts the PC solenoid valve in order to maintain a set shift feel.

• | WOT 1-2 Adapt - The PCM monitors the Vehicle Speed Sensor (VSS) and the engine rpm during a 1-2 Wide Open Throttle (WOT) shift. The PCM will adapt the 1-2 shift point during WOT.

• | Learn Tap - Accelerated PLM learn mode. A technician must road test the vehicle for 15 minutes (normal time 2-3 hrs).

| Important: The transmission may experience harsh, soft or mushy shifts for up to two days later.

Transmission adapts must be reset whenever the transmission is overhauled or replaced. In order to reset transmission adapts, select the following:

1. Scan tool
2. Miscellaneous test
3. A/T outputs
4. Clear or reset all adapts