LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Cadillac >> 2007 >> XLR Base >> Repair and Diagnosis >> Engine Mechanical >> Engine Exhaust System >> Diagnostic Information and Procedures >> DTC P166A >> Circuit/System Testing
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Circuit/System Testing

  1. Ignition OFF, disconnect the exhaust tail pipe flow control valve solenoid connector.
  2. Ignition ON, measure for 0 volts between the exhaust tail pipe flow control valve solenoid supply voltage circuit and ground.
    • If over 0 volts, test for short to voltage in exhaust valve solenoid supply voltage circuit.
  3. Ignition ON, use scan tool to command exhaust flow control relay ON, measure for 10 volts or above between the exhaust tail pipe flow control valve solenoid supply voltage circuit and ground.
    • If under 10 volts, test for short to ground in exhaust valve solenoid supply voltage circuit.
  4. If all circuits test normal replace the exhaust tail pipe flow valve control module.