Data Display Procedure

Enter diagnostics. See Entering Diagnostic Mode . Depress "LO" button on CCP to by-pass trouble codes. This will place diagnostic service mode in the system select level. Depress "LO" button until desired system is displayed. Select desired system by depressing the "HI" button. After desired system is selected, depressing "HI" button on CCP will enter the "Data" display level. See Figure.
Depressing the "LO" button on CCP will display next smaller test number for data display. If this button is pressed with lowest test number displayed, the highest test number will then appear.
Depressing the "HI" button on CCP will display next larger test number for the data display. If this button is pressed with highest test number displayed, the lowest test number will then appear.
When trouble shooting a malfunction, data displays can be used to compare vehicle with problems to a vehicle which is functioning properly.

The following are a summary of each parameter for Body Computer Module:

BD21 - Coolant Temperature

Is displayed in degrees Celsius (°C) from -40 to 151°C. This value is sent from the ECM to the BCM. If this circuit malfunctions as determined by the ECM, the ECM will send the BCM a "Failsoft" value for display.

BD22 - Commanded Air Mix Door Position

Is displayed in percent (%). A value close to 0% indicates a cold air mix and a value close to 100% indicates a warm air mix.

BD23 - Actual Air Mix Door Position

Is displayed in percent (%). This value should follow the commanded air mix door position (BD22) except when the door is commanded beyond its mechanical limits of travel.

BD24 - Air Delivery Mode

The air delivery mode is display as a number from 0 to 7. Each number is a code which represents the following delivery modes: 0 = MAX A/C, 1 = A/C, 2 = Intermediate, 3 = Heater, 4 = OFF, 5 = Normal Purge, 6 = Cold Purge and 7 = Front Defog.

BD25 - IN-CAR TEMPERATURE

Is displayed in degrees Celsius (°C), from -40 to 102.

BD26 - ACTUAL OUTSIDE TEMPERATURE

Is displayed in degrees Celsius (°C), from -40 to 93. This value represents actual sensor temperature and is not restricted by the features used to minimize engine heat affects on the customer display value.

BD27 - HIGH SIDE TEMPERATURE (Condenser Output)

Is displayed in degrees Celsius (°C) from -40 to 215.

BD28 - LOW SIDE TEMPERATURE (Evaporator Input)

is displayed in degrees Celsius (°C) from -40 to 93.

BD32 - SUNLOAD TEMPERATURE SENSOR

is displayed in degrees Celsius (°C) from -40 to 102.

BD40 - ACTUAL FUEL LEVEL

Is read in gallons between 0 and 19.0 (the display can read to 25.0). This value represents actual sensor position and is not restricted by the features used to eliminate fuel slosh affects on the customer display value.

BD41 - PRND321 (1987)

Is displayed in percent (%). "PARK" should display the highest percentage and drive "1" should display the lowest percentage.

BD41 - PRND321 (1988)

Is displayed in a 4 digit binary number. P = 0110, R = 0011, N = 1010, D = 1001, 3 = 0000, 2 = 0101, 1 = 1100.

BD42 - DIMMING POT

Is displayed in percent (%). A value close to 0% represents maximum dimming and a value close to 100% represents maximum brightness.

BD43 - TWILIGHT DELAY POT

Is displayed in percent (%). A value close to 0% represents minimum delay time and a value close to 100% represents maximum delay time.

BD44 - TWILIGHT PHOTOCELL

Is displayed in percent (%). A value close to 0% represents daylight and value close to 100% represents darkness.

BD51 - GENERATOR FIELD

Is displayed in percent (%). A value close to 0% represents minimum regulator on time and a value close to 100% represents maximum regulator on time.

BD71 - OIL PRESSURE

Is displayed in pounds-per-square-inch (PSI). This value should be zero with the engine off, and reflect the true oil pressure with the engine running.

BD98 - IGNITION CYCLE

Is the number of times that the BCM has been turned "OFF" since a BCM trouble code was last detected. After 100 ignition cycles without any malfunction being detected, all BCM codes are cleared.