1, 2 and 3 Digit Codes: 42

Name of Code:
41 - L-R Solenoid Circuit
42 - 2-4 Solenoid Circuit
43 - OD Solenoid Circuit
44 - UD Solenoid Circuit

When Monitored:
Ignition key is turned from "off" position to "run" position and/or ignition key is turned from "crank" position to "run" position, then every 10 second thereafter, or when a speed ratio or pressure switch error fault is detected.

Set Condition:
All four solenoids are tested for continuity continuously during vehicle operation. For solenoids that are currently energized, power is momentarily interrupted, then reenergized. For solenoids that are not currently energized, the solenoid is momentarily energized, then deenergized. Under both situations, if an inductive spike is not sensed by the Transmission Control Module (TCM) during the continuity check, it is retested twice. If it fails the test the third time, the appropriate code is set.

Theory of Operation:
Four solenoids are used to control the friction elements (clutches). The continuity of the solenoids circuits are periodically tested. Each solenoid is turned on or off depending on it's current state. An inductive spike should be detected by the TCM during this test. If no spike is detected, the circuit is tested again to verify the failure. In addition to the periodic testing, the solenoid circuits are tested if a speed ratio or pressure switch error occurs. In this case, one failure will result in the appropriate code being set.

Transmission Effects:
- 89-95 MY +96 MY V-i calibration - Transmission goes into neutral if code is set above 45 MPH, limp-in mode when vehicle speed is below 45 MPH
- 96 MY V-2 calibration (default desensitization) and 97 MY - Transmission goes into neutral if code is set above 22 MPH, limp-in mode when vehicle speed is below 22 MPH.

Possible Causes:
- Open or shorted solenoid circuit(s) between TCM and solenoid pack.
- Open ground circuit.
- TCM connector problems.
- 8 way connector problem.
- Defective solenoid pack.
- Defective TCM