Powertrain Controls - ECM/PCM

Diagnostic Chart:

Wiring Diagram:

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 appropriate line pressure 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
^ No DTC 75 stored.
^ The return amperage varies greater than 0.16 amp from the commanded amperage.
^ All conditions met for one second.

ACTION TAKEN (PCM WILL DEFAULT TO)
^ Harsh shifts.
^ Maximum line pressure.

DTC 73 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 ability of the PCM to command the pressure control solenoid.
2. This test checks internal transmission harness and the pressure control solenoid for high resistance.

DIAGNOSTIC AIDS
Check for poor connections at PCM and at transmission connector.