BCM Input Display Procedure
When troubleshooting a malfunction, the ECM, BCM or Lighting input display can be used to determine if switched inputs can be properly interpreted. When one of various input tests is selected, the state of that device is displayed as "HI" or "LO".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 and see if it changed state.
If a change of state occured, an "X" will appear next to the "HI/LO" indicator, otherwise an "O" 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. To view the BCM input displays, proceed as follows.
- 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 that system by depressing the "HI" button. After desired system is selected, "DATA" will be displayed. Depressing "LO" button will place system in the "INPUT" test level. Select that test level by depressing the "HI" button.
For available BCM and lighting input display parameters, see BCM INPUT DISPLAY PARAMETERS or LIGHTING INPUT DISPLAY PARAMETERS tables.
| BCM Input | Display |
|---|---|
| BI03 | The DRIVER DOOR JAMB SWITCH Display Is "LO" When The Driver's Door Is Open |
| BI04 | The PASSENGER DOOR JAMB SWITCH Display Is "LO" When The Passengers Door Is Open |
| BI08 (1987) | The LOW REFRIGERANT PRESSURE SWITCH Display Is "LO" When The System Is Low On Refrigerant |
| BI08 (1988) | The LOW REFRIGERANT PRESSURE SWITCH Display Is "LO" When The System Is Low On Refrigerant |
| BI09 | The WASHER FLUID LEVEL SWITCH Display Is "LO" When The Vehicle Is Low On Washer Fluid |
| BI10 | "LOW COOLANT" Displays "HI" With Proper Coolant Level |
| BI21 | "BRAKE FLUID LEVEL" Will Read "HI" With Proper Brake Fluid Level |
| BI24 (1987) | "PRND321 REVERSE SWITCH" Indicates Status Of Reverse Input, Circuit 24, Should Be "HI" With Vehicle In Reverse |
| BI30 | The TEMP/TIME SWITCH Display Is "LO" When The Button is Depressed |
| BI41 | The COOLING FAN FEEDBACK Display Is "LO" When The Cooling Fans Are Running |
| BI51 | The GENERATOR FEEDBACK Display Is "LO" When There Is A GENERATOR Problem (Or Engine Not Running) |
| BI60 | "THEFT ALARM" Indicates The Status Of The Alarm Output Of The Theft Module, "HI" Is A Normal Reading |
| BI61 | "DOOR LOCK SWITCH" Reads "HI" Until The Key Is Rotated To The Unlock Position In Either Door Lock Cylinder |
| BI62 | "SOFT TOP UP" Will Read "LO" With The Soft Top Up |
| BI63 | "HARD TOP CONNECTED" Will Read "LO" With Hard Top Installed & Connected |
| BI64 | "OIL LEVEL" Will Indicate "LO" With Proper Oil Level |
| BI90 | "RIGHT TURN SWITCH" Will Indicate "LO" With Right Turn Selected |
| BI91 | "LEFT TURN SWITCH" Will Indicate "LO" With Left Turn Selected |
| BI92 | "HEADLAMP SWITCH" Will Read "LO" With The Headlamp Switch On |
| BI93 | "HIGH BEAM SWITCH" Will Indicate "HI" Unless The Headlamp Dimmer Switch Is Pulled |
| BI94 | "ANTI-LOCK BRAKE FAILURE" Will Read "HI" Unless The EBCM Has Detected An ABS Problem |
| BI95 | "BRAKE SWITCH" Will Read "HI" With The Service Brake Applied |
| Lighting Input | Display | |
|---|---|---|
| LI01 | "COURTESY LAMP SWITCH" Will Read "LO" While The Panel Lamp Switch Is Depressed | |
| LI03 | "LIGHTS OFF SWITCH" Will Read "LO" With Twilight Switch Depressed | |
| LI04 | "TWILIGHT ENABLE SWITCH" Will Read "LO" With Twilight Switch Depressed | |
| LI05 | "HAZARD LAMP SWITCH" Will Read "LO" With Hazard Switch Depressed | |
| LI06 | "PARK LAMP SWITCH" Will Read "LO" With Park Lamp Switch Depressed | |
| LI08 | "FOG LAMP SWITCH" Will Read "LO" With Fog Lamp Switch Depressed | |