Checking The Component And Wiring

Check the resistance of the stop lamp switch with the switch pressed in and with the switch released. Take readings between terminals #1 and #2 (component side) on the stop lamp switch.

HINT: The stop lamp switch must be closed when the brake pedal is depressed. The resistance of the stop lamp switch must be infinite when the brake pedal is unaffected. 

Check the stop lamp switch and engine control module (ECM) connectors. Check for contact resistance. Check for oxidation.

Check the cable between stop lamp switch terminal #1 (cable harness side) and engine control module (ECM) terminal #B41 (#C41). Check for loose connections. Check for an open-circuit. Check for a short-circuit to ground. Check for a short-circuit to supply voltage.

Remedy as necessary.

Other information 

• see CONNECTING THE BREAKOUT BOX
• see SIGNAL SPECIFICATION
• see STOPLAMP SWITCH
• see CHECKING WIRING AND TERMINALS

Fig 2: Identifying 2-Bit Connector

Courtesy of VOLVO CARS CORPORATION

Fig 3: Identifying Ohm Meter

Courtesy of VOLVO CARS CORPORATION

Fig 4: Identifying Stop Lamp Switch

Courtesy of VOLVO CARS CORPORATION

Refer to VERIFICATION