PCM Inputs

DESCRIPTION AND OPERATION
The Powertrain Control Module (PCM) Inputs selection provides for testing of switches that input to the PCM. The input status is shown on the display as "HI" or "LO," the input cycle status is shown as "0" until the PCM sees that the input has cycled from "LO" to "HI" or "HI" to "LO" since the selected input was first displayed. After the PCM has seen the input cycle, the "0" will change to an "X" to indicate that the input being tested has cycled and has "passed" the input test. The PCM inputs available are as follows:

PI70 C/C Brake Switch
Cruise Control Brake Switch contacts of the Stop/Brake-Transmission Shift Interlock (BTSI) /Cruise Brake Switch. This input comes to the PCM at pin "1C2." PI70 should be "HI" with the brake pedal released and "LO" with the brake pedal depressed.

PI71 TCC Brake Switch
This input comes to the PCM at pin "1C4." PI71 should be "HI" with the brake pedal released and "LO" with the brake pedal depressed.

PI72 Throttle Position Switch
The throttle position switch is part of the Idle Speed Control (ISC) motor. When the throttle cam is lifted off the ISC motor, the switch opens. When the throttle cam rests on the ISC motor, the switch closes. This input comes to the PCM at pin "2A7." PI72 should be "LO" with the accelerator pedal released and "HI" with the accelerator pedal depressed.

PI79 Output Fault Status
This display shows the fault status of two of the PCM's quad drivers. PI79 will be "HI" with a fault and "LO" with no fault.

PI82 C/C ON/OFF Switch
This input comes to the PCM at pin "1D2." PI82 should be "LO" with this switch "OFF" and "HI" with this switch "ON."

PI83 C/C Set/Coast Switch
This input comes to the PCM at pin "1D3." PI83 should be "LO" with this switch "OFF" and "HI" with this switch "ON."

PI84 C/C Resume/Accel Switch
This input comes to the PCM at pin "1C3." PI84 should be "LO" with this switch "OFF" and "HI" with this switch "ON."

PI85 Power Steering Pressure Switch
This input comes to the PCM at pin "1C9." PI85 should be "HI" with the steering wheel on center and "LO" with the engine running and the steering wheel at full lock (left or right).