27 All Pressure Switch Circuits

THEORY OF OPERATION:
The transmission system uses three pressure switches to monitor the fluid pressure in the L-R, 2-4, and OD elements. The pressure switches are continuously monitored for the correct states in each Gear as illustrated.





This code is set if the L-R and 2-4 and OD pressure switches are either open or closed at the wrong time in a given gear. This code indicates that all of the pressure switches indicated the wrong state at the time the fault was set.

LIMP-IN:
YES (89-95 MODEL YEARS)

WHEN MONITORED/SET CONDITIONS:
Whenever the engine is running.

TRANSMISSION EFFECTS:
- 89-95 model year + 96 V-1 calibration - relay open limp-in mode.
- 96 model year V-2 calibration (default desensitization) and 97 model year - Code eliminated, codes 21 22 and 24 will be set.

POSSIBLE CAUSES:
- If code 35 is present, ignore code 27 and perform code 35 diagnostic procedures.
- If code 35 is not set, follow diagnostic procedures for codes 21, 22 and 24.