Powertrain Controls - ECM/PCM

DTC 66 3-2 Control Solenoid Circuit Fault:

3-2 Solenoid Circuit:

CIRCUIT DESCRIPTION
Hydraulically, the 3-2 control solenoid coordinates the apply rate of the 2-4 band with hydraulic release, of the 3-4 clutch during a 3-2 downshift.
The Powertrain Control Module (PCM) continually monitors the 3-2 circuit duty cycle depending on the commanded state of the circuit. When the transmission is in first gear the duty cycle of the solenoid is equal to zero. When the transmission is in second gear or higher the duty cycle of the solenoid will be about 90%. When the transmission downshifts, 3-2, the duty cycle of the solenoid will drop.

DTC 66 WILL SET WHEN
^ The PCM commands the solenoid "ON," and the voltage remains high (B+) for four seconds.
^ The PCM commands the solenoid "OFF," and the voltage remains low (zero volts) for four seconds.

ACTION TAKEN (PCM will default to)
^ A delayed (soft) landing to third gear.
^ Third gear starts.

DTC 66 WILL CLEAR WHEN
The fault condition(s) no longer exist, and the ignition switch is cycled "OFF" then "ON."

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This test checks the function of the 3-2 control solenoid and the internal transmission harness.
2. This test checks for power to the 3-2 control solenoid from the ignition through the fuse.

DIAGNOSTIC AIDS
Check all connections at the transmission connector.
The 3-2 control solenoid feedback normally oscillate "ON"/"OFF" when the duty cycle is applied. An open in the ignition feed circuit will cause multiple DTC(s) to set.