LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Cadillac >> 2017 >> CT6 Plug-In >> Repair and Diagnosis >> Electrical >> Instrument Panel System Displays And Gauges >> Diagnostic Information and Procedures >> Engine Oil Level Sensor Diagnosis >> Circuit/System Testing
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Circuit/System Testing

NOTE: Verify proper engine oil level before continuing with diagnosis.
  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B35 Engine Oil Level Switch. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 5 Ω between the ground circuit terminal 1 and ground.
    • If 5 Ω or greater 
    1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
    2. Test for less than 2 Ω in the ground circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, repair the open/high resistance in the ground connection.
    • If less than 5 Ω 
  3. Ignition ON.
  4. Verify the scan tool Engine Oil Level Switch parameter reads Low.
    • If the Engine Oil Level Switch parameter reads OK 
    1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
    2. Test for infinite resistance between the signal circuit terminal 2 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the K20 Engine Control Module.
    • If the Engine Oil Level Switch parameter reads Low 
  5. Install a 3A fused jumper wire between the signal circuit terminal 2 and the ground circuit terminal 1.
    NOTE: If a short to voltage is found on the signal circuit, the fuse in the 3A jumper wire will open.
  6. Verify the scan tool Engine Oil Level Switch parameter reads OK.
    • If the Engine Oil Level Switch parameter reads Low 
    1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON.
    2. Test for less than 1 V between the signal circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V
    3. Test for less than 2 Ω in the signal circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance on the circuit.
      • If less than 2 Ω, replace the K20 Engine Control Module.
    • If the Engine Oil Level Switch parameter reads OK 
  7. Test or replace the B35 Engine Oil Level Switch.
scientia non olet · About LEMON Manuals