IPC Input Data Display

When troubleshooting a malfunction, the Electronic Control Module (ECM), Body Control Module (BCM), or Instrument Panel Cluster (IPC) input display can be used to determine if the switched inputs can be properly interpreted.

When one of the various input tests is selected, the state of that device is displayed as "HI" or "LO". In general, the "HI" and "LO" refer to the input terminal voltage for that circuit. The display also indicates if the input changed state so that the technician can activate or deactivate any listed device and return to the display to see if it changed state.

If a change of state occurred, an "X" will appear next to the HI/LO indicator, otherwise a "O" will remain displayed. The "X" will only appear once per selected input, although the HI/LO indication will continue to change as the input changes. Some tests are momentary and the "X" can be used as an indication of a change.

The following is a list of Instrument Panel Cluster (IPC) inputs:
II78 The headlamps switch display is "HI" whenever the headlamps are on.
II79 The high beam switch display is "LO" as long as the lever is pulled in.
II80 The dimming sentinel switch display is "LO" whenever the system is on.
II81 The dimming sentinel photosensor display is "HI" whenever it senses light.
II82 The twilight enable switch display is "LO" whenever the system is on.