24 L-R Pressure Switch Circuit

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Part 2 Of 3:

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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.

LIMP-IN:
- YES (1989 -1995)
- NO (1996 -1997)

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

TRANSMISSION EFFECTS:
- 89-95 model year + V-1 calibration - relay open limp-in mode.
- 96 model year V-2 calibration (default desensitization) and 97 model year - If a set condition is identified, 1st gear and torque converter lock-up (EMCC) will be inhibited. The vehicle will launch in 2nd gear and shift normally through the gears without allowing EMCC. If during the same key start, the set condition is no longer valid, the transmission will return to normal operation (1st and EMCC available). A relay open limp-in will not occur unless code 24 is accompanied by a code 28.

POSSIBLE CAUSES:
- If code 35 is present, ignore code 24 and perform code 35 diagnostic procedures
- L-R pressure switch sense circuit open or shorted to ground between TCM and solenoid pack
- L-R pressure switch sense circuit shorted to battery
- Solenoid pack
- Valve body - solenoid switch valve stuck in LU position. (May be accompanied by a code 37)
- Loose valve body bolts
- Plugged filter - internal transmission or torque converter failure
- Defective TCM