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Home >> Saab >> 2001 >> 9-5 Base, 4D Sedan, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Fault Code Diagnosis >> P1576: Brake Light Switch Circuit - Open/Short To B+ >> Fault Isolation Procedure

Fault Isolation Procedure

  1. Checking brake-light functionality: If the brake lights are functioning correctly, go to next step, otherwise see method description in service category 'Lighting and signaling systems' and go to step  3.
  2. Rectifying the lead: The lead from crimped connection J61 to control module pin 63 is faulty. Rectify the fault and go to next step.
  3. Checking the control module brake light input:
    • Turn the ignition switch to the ON position.
    • Contact ECM.
    • Read value: Brake Light (ECM).
    • The reading should be ON when the brake pedal is depressed and OFF when the brake pedal is released.
    If this function is correct, the fault has been rectified. If the function is not correct, the ECM is faulty and must be replaced.
Fig 1: Brake Light Switch Circuit (4-Cyl)
G00207390Courtesy of SAAB-SCANIA OF AMERICA, INC.
Fig 2: Brake Light Switch Circuit (V6)
G00207437Courtesy of SAAB-SCANIA OF AMERICA, INC.
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