Checking the high level stop lamps

Check the central electronic module (CEM) and the high-mounted stop lamp connectors. Check for contact resistance and oxidation. Check for loose connections. Check for damage carefully.

Check the power supply cable between central electronic module (CEM) terminal #5B (#A25) and brake light connector terminal #1. Check for an open-circuit. Check for a short-circuit to supply voltage.

Check the ground lead between brake light connector terminal #5 and the ground terminal. Check for an open-circuit. Check for a short-circuit to supply voltage.

Try a new brake light if no faults were found.

Remedy as necessary.

Other information: 

• To access / replace the high mounted stop lamp, see Stop lamp, rear windshield, replacing
• To access the central electronic module (CEM), see Central electronic module (CEM), replacing
• To connect the breakout box, see Connecting the breakout box
• For information about signals:
  • -2004: Signal specification
  • 2005-: Signal specification
• Checking wiring and terminals

Fig 2: Breakout Box

Fig 3: Identifying Ohm Meter

Fig 4: 10 CD Changer Connector Terminals

Refer to Verification