Operation CHARM: Car repair manuals for everyone.

Data Parameters

BD20 Commanded Blower Voltage

Display Range: -2.0 to 18.0
Display Units: Volts
BD20 is the blower voltage that the BCM is requesting of the power module.

BD21 Coolant Temperature

Display Range: -40 to 151
Display Units: Degrees Celsius (°C)
BD21 is the coolant temperature sent from the PCM to the BCM. If the coolant temperature sensor circuit malfunctions causing PCM Code P014 or P015 to set, the PCM will send the BCM a "Failsoft" value for display.

BD22 Commanded Air Mix Door Position

Display Range: 0 to 100
Display Units: Percent (%)
BD22 is the air mix door position that the BCM is requesting of the programmer. 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

Display Range: 0 to 100
Display Units: Percent (%)
BD23 should follow the commanded air mix door position (BD22) when BD22 is between 20 and 95.

BD24 Air Delivery Mode

Display Range: 0 to 8
Display Units: Code
BD24 is displayed as a number from 0 to 8. Each number is a code which represents one of the following air delivery modes:

0 - MAX A/C (REGRC)
1 - A/C
2 = Intermediate (DEFROST)
3 = Heater
4 = OFF
5 = Normal Purge
6 = Cold Purge
7 = Front Defog
8 = A/C Purge

BD25 In-Car Temperature

Display Range: -40 To 102
Display Units: Degrees Celsius (°C)
BD25 is the interior temperature reading of the vehicle, that is received at the BCM from a sensor mounted in the It?, to the left of center.

BD26 Actual Outside Air Temperature

Display Range: -40 To 102
Display Units: Degrees Celsius (°C)
BD26 is the actual outside air temperature reading, around the vehicle, that is received at the BCM from a sensor mounted in a protective housing just behind the radiator grille.

BD27 High Side Temperature (CONDENSER OUT)

Display Range: -40 To 215
Display Units: Degrees Celsius (°C)
BD27 is the high side temperature reading, of the A/C refrigerant, that is received by the BCM from a sensor mounted in the liquid refrigerant line between the condenser and the orifice tube.

BD28 Low Side Temperature (Evaporator in)

Display Range: -40 To 102
Display Units: Degrees Celsius (°C)
BD28 is the low side temperature reading, of the A/C refrigerant, that is received by the BCM from a sensor mounted in the refrigerant line between the orifice tube and the evaporator.

BD32 Sun Load Temperature

Display Range: -40 To 102
Display Units: Degrees Celsius (°C)
BD32 is the sun load temperature reading, of the heat load induced in the vehicle by the sun, that is received by the BCM from a sensor mounted under the defroster grille, center position, at the base of the windshield.

BD40 Actual Fuel Level

Display Range: 0 To 25.5
Display Units: Gallons
BD40 is the approximate fuel level reading, of the fuel in the fuel tank, that is received by the BCM from a sensor mounted in the fuel tank.

BD42 Dimming Pot

Display Range: 0 To 100
Display Units: Percent (%)
BD42 is the dimming pot reading, of the JIP light intensity control, that is received by the BCM from a potentiometer mounted in the headlight (left) switch assembly. A value close to 0% represents maximum dimming and a value close to 100% represents maximum brightness

BD43 Twilight Delay Pot

Display Range: 0 To 100
Display Units: Percent (%)
BD43 is the twilight delay pot reading, of the twilight sentinel, that is received by the BCM from a potentiometer mounted above the headlight switch on the I/P A value close to 0% represents minimum delay time and a value close to 100% represents maximum delay time.

BD44 Twilight Photocell

Display Range: 0 To 100
Display Units: Percent (%)
BD44 is the twilight photocell reading, of the twilight sentinel, that is received by the BCM from a photo-voltaic sensor mounted in the front defroster grille. A value close to 0% represents daylight and a value close to 100% represents darkness.

BD50 Battery Voltage

Display Range: 0 To 16.3
Display Units: Volts
BD50 is the battery voltage reading that is received by the BCM from the central power supply.

BD51 Generator Field

Display Range: 0 To 100
Display Units: Percent (%)
BD51 is the generator field reading, of the percent "ON" time of the regulator, that is received by the BCM from the generator. A value close to 0% represents minimum regulator "ON" time and a value close to 100% represents maximum regulator "ON" time.

BD60 Car Speed

Display Range: 0 To 15g
Display Units: Miles Per Hour (MPH)
BD60 is the car speed reading that is received by the BCM from the vehicle speed sensor mounted on the transaxle.

BD61 Engine Rpm

Display Range: 0 To 6375
Display Units: Revolutions Per Minute (RPM)
BD61 is the engine speed reading, in revolutions per minute, that is received by the BCM from the PCM.

BD71 Oil Pressure

Display Range: 0 to 120.0
Display Units: PSI
BD71 should be zero with the engine "OFF," and reflect the true oil pressure with the engine running.

BD98 ignition Cycle

Display Range: 0 to 100
Display Units: Number of Cycles
BD98 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

Display Range: 0 to 9999
Display Units: Code
BD99 is used to identify what PROM is currently installed in the BCM.