Input

ECM INPUT DISPLAYS:

When troubleshooting a malfunction the ECM 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 could 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. 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 ECM inputs:

EI71 The brake switch "BRK SW" display is "LO" with the service brake depressed.

EI74 The "PARK-NEUT" display is "LO" when the vehicle is in park or neutral.

EI78 The power steering pressure switch "POWER STRG" display is "LO" when power steering pressure (effort) is high, engine running and steering wheel in crimp position.

EI79 The second gear switch "2ND GEAR" display is "HI" when the vehicle is in second gear.

EI80 The third gear switch "3RD GEAR" display is "HI" when the vehicle is in third gear.

EI82 The fourth gear switch "4TH GEAR" display is "HI" when the vehicle is in fourth gear.