Override

BCM OVERRIDE DISPLAYS:

When troubleshooting a malfunction, the BCM override feature allows testing of certain system functions regardless of normal program instructions. Upon selecting a test, that selections current operation will be represented as a percentage of its full range, and this value will be displayed on the ECC panel. If the selected override is not allowed under the current conditions a " =- =- " display will result.

Touching the "WARM" or "COOL" buttons on the ECC panel begins the override. The "WARM" button will increase the value while the "COOL" button will decrease it. Normal Program control can be resumed in one of three ways:

1. Selection of another override test will cancel the current override.

2. Selection of another system will cancel the current override.

3. Overriding the value beyond either extreme (0 or 99) will display "--" momentarily and then jump to the normal program control.

The override test type is unique in that any other test type within the selected system may be active at the same time. After selecting in override test, touching the "OFF" button will allow selection of another test type, however, the ECC panel will continue to display the selected override. By selecting another test type and test, and then touching the "WARM" or "COOL" buttons, it is possible to monitor the effect of the override on different vehicle parameters.

BS00 The "NONE" display will not display any value as this is a resting spot where no overrides will be controlled. This is a handy spot to go to stop the override without having to go back to the level where the system is selected.

BS01 "PROGRAM NO" As the heating and air conditioning operating conditions change, the program number will automatically change in response. The automatic calculation of program number can be bypassed by a manual override feature using the "WARM" and "COOL" buttons on the ECC panel. Touching the "WARM" button will force the program number to increase at a controlled rate until the value of "99" is reached. "99" represents the "Max Heat" mode of climate control operation. Touching the "COOL" button will force the program number to decrease until the value of "O" is reached which represents the "MAX A/C" mode. This manual override of automatic program number calculation will continue until the override is stopped. This allows the technician to control the program number to any number from "O" to "99" and simultaneously observe the reaction of any of the BCM data parameters.

BS03 "BULB DIM" As the dim pot is moved the incandescent dimming number will automatically change in response (if outside lights are on). The automatic control of dimming can be bypassed by a manual override feature using the override control. "99" represents the max brightness of incandescent displays and "O" represents the max dimming of incandescent lighting. (Outside lights do not have to be on to override incandescent dimming). This allows the technician to control the dimming number from "O" to "99."

BS05 "C/C SERVO" The cruise control switch must be on for this test to work. The automatic calculation of cruise control position number can be bypassed by a manual override feature using the override. "99" represents the max cruise position (WOT) and "O" represents the minimum cruise position (closed throttle). This manual override of automatic cruise control position number calculation will continue until the override is stopped. This allows the technician to control the cruise control position number to any number from "0" to "99" and simultaneously observe the reaction of the data value for cruise servo position (BD70). The two should agree with each other +/- 3% except when the servo is commanded beyond its mechanical limits of travel. Since this test is not allowed with engine running remember that there is usually only enough vacuum in the storage tank to stroke the servo once.

BS06 "BLOWER SPD" This override will control the HVAC blower to full speed at a display of "99" by pressing the "WARM" button. The "COOL" button will slow the blower to a minimum speed at a display of "O0."

BS07 "OPTION 1" This override allows the modification of the option contents that the BCM was programed with at the factory (stored in EEPROM) Refer to explanation of BD90 for details on possible option content numbers. The display will show what option number is currently in the vehicle upon entry. To change the option content number press the "WARM" or "COOL" buttons for override control until the desired number, corresponding to vehicle equipped options, appears. When the desired number appears, press and hold the "LO" and "DEF" ECC switches simultaneously for 5.0 seconds. This will reprogram the BCM EEPROM to the number (options) displayed on the IPC.

BSO8 "OPTION 2" This override allows the modification of the option contents that the BCM was programed with at the factory (stored in EEPROM). Refer to explanation of BD91 for details on possible option content numbers. The display will show what option number is currently in the vehicle upon entry. To change the option content number press the "WARM" or "COOL" buttons for override control until the desired number, corresponding to vehicle equipped options, appears. When this number appears on the ECC panel, press and hold the "LO" and "DEF" ECC switches simultaneously for 5.0 seconds. This will reprogram the BCM EEPROM to the number (options) displayed on the IPC.