Input
Input DisplaysInput displays are operated as defined under "C". "Selecting the Test" under the heading "How to Operate Service Mode". When troubleshooting a malfunction, the ECM, BCM, or 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 "0" 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 ECM, BCM and IPC inputs:
ECM:
E171 The BRAKE SWITCH display is "LO" when the brake pedal is depressed.
E172 The THROTTLE SWITCH display is
"HI" when the accelerator pedal is
depressed.
E174 The PARK-NEUTRAL (P/N) display is "LO" when the vehicle is in park or Neutral.
E178 The POWER STEERING PRESSURE SWITCH display is "LO" when power steering pressure (effort) is high. wheel in crimp position