For 1990-2009 cars

### Body Control Module

This vehicle is equipped with the Supplemental Inflatable Restraint (SIR) System. Refer to Disabling the SIR System in SIR.

### Electrostatic Discharge (ESD)

The body control module (BCM) is sensitive to electrostatic discharge. ESD can damage many solid state components. Not all components that are susceptible to damage from ESD are labeled with the ESD precautionary symbol. Exercise caution when handling all solid state electrical components.

Avoid damaging solid state components by taking the following precautions:

• | Discharge personal electricity by touching a metal ground point after sliding across the vehicle seat, sitting, rising, or walking.

• | Do not touch the exposed electrical terminals on a component with your fingertips or tool. The connector that you are checking may be tied into a circuit that is susceptible to damage by ESD.

• | Do not allow a screwdriver or similar tool to contact exposed terminals when disconnecting a connector.

• | Do not remove the protective packaging of the solid state component until you are ready to install the solid state component.

• | Unless specified in a particular diagnostic procedure, avoid jumpering components or connectors, grounding components or connectors, or using test equipment probes on components or connectors.

• | When a diagnosis requires the use of test equipment probes, connect the ground lead first.

• | Touch the solid state component's package to a ground before opening the package.

• | Do not lay the solid state component on a metal workbench or on top of an electrically operating appliance or piece of equipment.

• | Do not drop the solid state component.

### Visual/Physical Inspection

One of the most important checks, prior to performing any diagnostic activity, is a careful visual inspection of complaint related wiring and components. This can often lead to fixing a malfunction without any further steps. Inspect battery charge level (green eye) to assure battery is not discharged. Inspect for blown fuses. Inspect all related vacuum and electrical circuits for pinches, cuts, or disconnects. A good visual inspection is very important.

### General Service

The diagnostic flow charts contained in this service manual are used to find and repair malfunctions which the self-diagnostics of the module have found. If a diagnostic trouble code (DTC) is a history DTC, the malfunction may be intermittent. Try wiggling the wiring and the connectors as this can often cause the malfunction to appear. It is not recommended to replace modules based on history codes.

It is recommended to use a scan tool in performing system diagnostics. The scan tool displays, shown in the diagnostics section of this service manual, will assist in diagnosing body control module (BCM) related malfunctions. The diagnostic flow charts in this manual rely on data from a scan tool to make repair decisions. Do not use a BCM from another vehicle to aid in diagnosis. BCMs are not interchangeable after they have been installed.