1-2 Shift Solenoid

WITH 4L60-E AUTOMATIC TRANSMISSION

1-2 Shift Solenoid Circuit Check:

Shift Solenoid Chart:

1-2 Shift Solenoid Circuit:

Circuit Description:
1-2 shift solenoid is attached to the valve body and is a normally open to exhaust valve. The PCM activates the 1-2 solenoid by grounding CKT 1222 with an internal quad-driver. 1-2 shift solenoid is "ON" in first and fourth gears and "OFF" in second and third gears. When "ON", the 1-2 shift solenoid redirects fluid to act on the shift valves.

Test Description:
Number(s) below refer to circled number(s) on the diagnostic chart.

1. This test checks 1-2 shift solenoid and the internal transmission wiring harness for shorts.
2. This test checks for power to 1-2 shift solenoid from the ignition through the fuse.
3. This test checks CKT 1222 for a short to ground.
4. This test checks the PCM ability to ground or control 1-2 shift solenoid.

Diagnostic Aids:
Check all connections at the transmission pass-thru connector.
Refer to "PCM Intermittent Diagnostic Trouble Codes or Performance."