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Home >> Infiniti >> 2004 >> Q45 >> Repair and Diagnosis >> Engine Performance >> Engine Control System >> DTC P1805: Brake Switch >> Diagnostic Procedure >> 4. Check Stop Lamp Switch Input Signal Circuit For Open And Short
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4. Check Stop Lamp Switch Input Signal Circuit For Open And Short

  1. Disconnect ECM harness connector.
  2. Disconnect stop lamp switch harness connector.
  3. Check harness continuity between ECM terminal 106 and stop lamp switch terminal 2.

    Refer to Wiring Diagram.

    1. Continuity should exist. 
  4. Also check harness for short to ground and short to power.

OK or NG 

OK: GO TO 6.

NG: GO TO 5.