Tech - Intermittent Multifunction Alarm Activation (Install New ABS Stoplamp Sw)

Some customers may comment that the multifunction alarm activates intermittently.

A worn stop lamp switch may cause this condition. A partial connection or worn contact points can "confuse" the module and cause the alarm to activate.

For all applications, Engineering has recently standardized on three-contact stop lamp switches formerly used for ABS vehicles only. This change is effective for both production and service. Use the appropriate new three-contact ABS stop lamp switch on both ABS and non-ABS equipped vehicles.

The previous stop lamp switches for non-ABS air and hydraulic brake applications had two internal contacts (4 pin-outs). The new switches formerly used for ABS applications have three sets of contacts (6 pin-outs).

In addition, the new switches feature electroless nickel-plated contacts and lubricant on the internal slide rails. The new switches should reduce wear and intermittent alarm activation.

Refer to the Hydraulic Brakes subsection on the appropriate Service Manual for stop lamp switch replacement information.

Important: When servicing non-ABS equipped vehicles with a new switch, the third set of exposed pins is not used. On ABS-equipped vehicles, the third set of pins feed a brake switch signal to the ABS controller.

Parts are currently available from GMSPO.

For vehicles repaired under warranty, use: