Input/Output Diagnostics

After all DTCs have been displayed, BCM provides individual input and output diagnostic checks for all functions. All systems (except interior lights, tamper signal and RKE input) will indicate each change in system status (i.e., driver's door opened) with a single flash and chime bong. If the proper feedback is not received, then there is an open or short in that circuit or a faulty component.
RKE input is tested when diagnostics is entered. BCM sends a signal to Remote Control Door Lock Receiver (RCDLR), and will setDTC 8 if a signal is not returned.
To test interior lights and tamper signal, change interior light switch from an inactive to an active state to allow BCM to go through cycles. See INTERIOR LIGHTS/TAMPER SIGNAL INPUT/OUTPUT DIAGNOSTIC table. Each time interior lights change from an inactive to an active state, BCM goes to next cycle and chime bongs to let technician know what cycle BCM is in.

INTERIOR LIGHTS/TAMPER SIGNAL INPUT/OUTPUT DIAGNOSTIC

Cycle No.

Action

Battery Output To Courtesy Lights Deactivated

Battery Output To Courtesy Lights Activated

⁽¹⁾ If Mileage Flag Is Set, Courtesy Output Is Inactive, Then Activated For One Second

4 ⁽²⁾

Exterior Lights Activated For One Second

5 ⁽²⁾

Horn Activated For 0.5 Second

6 ⁽²⁾

Shock Sensor Diagnostics Enabled & Security Warning Indicator Turned On

7 ⁽²⁾

Shock Sensor Diagnostics Disabled & Security Warning Indicator Turned Off

⁽¹⁾	Interior lights will change state when this occurs.

⁽²⁾	BCM-4 only.