Powertrain Controls - ECM/PCM

DTC 73

PRESSURE CONTROL SOLENOID (PCS) CIRCUIT

Circuit Description:

The pressure control solenoid is a PCM controlled device used to regulate transmission line pressure. The PCM compares TP voltage, engine RPM and other inputs to determine the line pressure appropriate for a given load. The PCM will regulate the pressure by applying a varying amperage to the pressure control solenoid. The applied amperage can vary from 0.1 to 1.1 amp. The PCM then monitors the amperage at the return line.

DTC 73 Will Set When:

The return amperage varies greater than 0.16 amp from the commanded amperage, for at least one second, and no DTC 75 stored.

Action Taken (PCM will default to):

Full line pressure will be applied causing harsh shifts. DTC 73 will be stored in the PCM memory but will not turn "ON" the MIL (Malfunction Indicator Lamp).

DTC 73 Will Clear When:

The fault condition(s) no longer exist, and the ignition switch 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 ability of the PCM to command the pressure control solenoid.
2. This test checks internal transmission harness and the pressure control solenoid for incorrect resistance.

Diagnostic Aids:

Check for poor connections at PCM and at transmission connector.






If pressure readings differ greatly from the line pressure chart, refer to the Diagnostic Chart Diagnostic Trouble Code Descriptions.