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Data Displays

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.

BD20 - COMMANDED BLOWER VOLTAGE

Is read in volts from -2.9 to 18.0 Volts.

BD21 - COOLANT TEMPERATURE

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

BD22 - COMMANDED AIR MIX DOOR POSITION

Is displayed in percent (%). A value close to 0% represents a max cold air mix and a value close to 100% represents a max heat air mix.

BD23 - ACTUAL AIR MIX DOOR POSITION

Displayed in percent (%). This value should follow commanded air mix door position (BD22) when BD22 is between 20 and 95.

BD24 - AIR DELIVERY MODE

The is displayed as a number from 0 to 7. Each number is a code which represents the following air delivery modes: 0 = MAX A/C, 1 = A/C, 2 = Intermediate, 3 = Heater, 4 = OFF, 5 = Normal Purge, 6 = Cold Purge, 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 102. 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

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

BD28 - LOW SIDE TEMPERATURE

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

BD32 - SUNLOAD TEMPERATURE SENSOR

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

BD40 - ACTUAL FUEL LEVEL

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

BD41 - PRND321

PRND321 is displayed in a 4 digit binary number P=0110, R=0011, N=1010, 3=0000, 2=0101, 1=1100.

BD42 - DIMMING POT

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.

BD50 - BATTERY VOLTAGE

Battery voltage is read in volts between zero and 16.3.

BD51 - GENERATOR FIELD

Generator field is displayed in percent (%). A value close to zero % represents minimum regulator on time, and a value close to 100% represents maximum regulator on time.

BD60 - VEHICLE SPEED

Vehicle speed is displayed in miles per hour (MPH) from zero to 159.

BD61 - ENGINE SPEED

Engine speed is displayed in RPM from zero to 6375.

BD71 - OIL PRESSURE

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

BD99 - BCM PROM ID

Is used to identify what PROM is currently used in the BCM.