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Home >> Cadillac >> 2018 >> CT6 Plug-In >> Repair and Diagnosis >> Accessories & Equipment >> Drivers Assistance Systems - ADAS >> Driver Assistance Systems >> Diagnostic Information and Procedures >> DTC B148D >> Circuit/System Testing
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Circuit/System Testing

  1. Ignition OFF and all vehicle systems OFF, disconnect the X1 harness connector at the K186 Multifunction Energy Storage Capacitor Control Module. It may take up to 2 min for all vehicle systems to power down.
  2. Test for less than 10 Ω between the low reference circuit terminal 12 and ground.
    • If 10 Ω or greater 
    1. Ignition OFF.
    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, replace the K124A Active Safety Control Module 1.
    • If less than 10 Ω 
  3. Test for less than 10 Ω between the low reference circuit terminal 13 and ground.
    • If 10 Ω or greater 
    1. Ignition OFF.
    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, replace the K124B Active Safety Control Module 2.
    • If less than 10 Ω 
  4. Ignition ON.
  5. Test for 3.4 to 4.8 V between the test points: Signal circuit terminal 4 & Ground
    • If less than 3.4 V 
    1. Ignition OFF, disconnect the harness connector at the K124A Active Safety Control Module 1.
    2. Test for infinite resistance between the signal circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K186 Multifunction Energy Storage Capacitor Control Module.
    • If greater than 4.8 V 
    1. Ignition OFF, disconnect the harness connector at the K124A Active Safety Control Module 1.
    2. Test for less than 1 V between the signal circuit and ground.
      • If greater than 1 V, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K186 Multifunction Energy Storage Capacitor Control Module.
    • Go to next step: If between 3.4 and 4.8 V 
  6. Test for 3.4 to 4.8 V between the test points: Signal circuit terminal 5 & Ground
    • If less than 3.4 V 
    1. Ignition OFF, disconnect the harness connector at the K124B Active Safety Control Module 2.
    2. Test for infinite resistance between the signal circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K186 Multifunction Energy Storage Capacitor Control Module.
    • If greater than 4.8 V 
    1. Ignition OFF, disconnect the harness connector at the K124B Active Safety Control Module 2.
    2. Test for less than 1 V between the signal circuit and ground.
      • If greater than 1 V, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K186 Multifunction Energy Storage Capacitor Control Module.
    • Go to next step: If between 3.4 and 4.8 V 
  7. Test or replace the K186 Multifunction Energy Storage Capacitor Control Module.
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