Part 1 of 2

DTC P089:

Shift Solenoid Circuit:

CIRCUIT DESCRIPTION:
Transaxle pressure is modified by an adaptive modifier used to control the gear shift execution time. This diagnostic test checks the shift execution and the time it takes to accomplish it. If it takes longer than .55 second and the adaptive modifier cannot shorten this time, the counter will be incremented. When the counter reaches 5, Code P089 will set.

TEST CONDITION(S):
1. Codes P021, P022, P024, P056, P057, P059, and P075 not set.
2. Vehicle speed 10 mph or greater.
3. Throttle position 15.7 degrees or greater.
4. Transaxle temperature 90°C or greater.

FAILURE CONDITION(S):

Case I
1-2 shift time .55 second or greater and adapt cannot shorten shift time for 5 shifts.

Case II
2-3 shift time .55 second or greater and adapt cannot shorten shift time for 5 shifts.

Case III
3 - 4 shift time .55 second or greater and adapt cannot shorten shift time for 5 shifts.

ACTION TAKEN:
1. PCM turns "ON" the �SERVICE ENGINE SOON" MIL.
2. PCM deenergizes the transaxle pressure control solenoid.

NOTES ON FAULT TREE:
1. Refer to HYDRA-MATIC 4T80-E AUTOMATIC TRANSAXLE DIAGNOSIS for pressure gage installation procedure.