Code 66, 3-2 Control Solenoid Circuit Fault: Notes

The 3-2 control solenoid hydraulically coordinates the apply rate of the 2-4 band with hydraulic release of the 3-4 clutch during a 3-2 downshift. 3-2 circuit duty cycle is continually monitored by the PCM depending on the command state of the circuit. When the transmission is in 1st gear the duty cycle of the solenoid is equal to zero. When the transmission is in 2nd gear or higher, the duty cycle of the solenoid will be about 90 percent. When the transmission downshifts 3-2, the duty cycle of the solenoid will be about 20 percent.

For example, if the PCM commands the solenoid on, the duty cycle on that circuit should drop when the solenoid is grounded. If voltage stays up for 4 seconds, Code 66 will set. If the 3-2 control solenoid is off, the duty cycle on the circuit should remain high. If voltage drops for 4 seconds, Code 66 will set. When code is set, a soft landing to 3rd gear will occur.

1. This test checks 3-2 control solenoid and internal transmission harness for short circuits.
2. This test checks for power, from the ignition through the fuse, to the 3-2 control solenoid.
3. This test ensures circuit No. 897 is not shorted to ground.
4. This test checks ability of PCM to ground or control 3-2 control solenoid. If bidirectional scan tester is not available, solenoid may be activated by grounding ALDL test terminal "B" with ignition on and engine off.