Code 25

CIRCUIT DESCRIPTION
The 1-2/3-4 solenoid is a simple ON/OFF solenoid located in the main case valve body. The solenoid is the normally closed-type. In second or third gear, the TCM energizes the solenoid to open a fluid inlet port. When the port is open, fluid pressure actuates the shift valve.

TEST DESCRIPTION
Numbers below refer to circled numbers on the diagnostic chart.
1. This test checks the continuity of the solenoid windings and the wires to the solenoid.
2. This test checks for a short to voltage at terminal 48 of the TCM connector.
3. The wire from terminal 48 of the TCM connector may be shorted to a supply wire of another solenoid at main case connector. Also, the wire between terminal 54 of the TCM connector and the main case connector may be open.
4. The wire from terminal 3(D) of the main case connector may be shorted to a supply wire of another solenoid. Also, the wire between terminal 4(C) of the main case connector and the solenoid may be open.

DIAGNOSTIC AIDS
Trouble Code 25 sets when the TCM detects an open or a short to voltage at terminal 48. In the event of an electrical failure, both the 1-2/3-4 and 2-3 shift solenoids are de-energized. The transmission will drive in fourth gear at D & 3 range. Lower ranges and reverse may be selected manually.

CIRCUIT DIAGRAM

1-2/3-4 Shift Solenoid Circuit:

CODE 25 DIAGNOSTIC CHART

Code 25 Diagnostic Chart: