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Home >> Chevrolet >> 2018 >> Equinox L >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 17 (Engine Controls And Fuel - 1.6L (LH7) Diesel - Diagnostic Information And Procedures (P205B - P2BAA) And Symptoms) >> Diagnostic Information And Procedures >> DTC P227B: Barometric Pressure (BARO) Sensor 2 Performance >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.
  1. Verify the conditions listed below do not exist with the B75C Multifunction Intake Air Sensor:
    • Damage.
    • Restrictions in the inlet port.
    • If a condition exists 

      Repair or replace the B75C Multifunction Intake Air Sensor as necessary.

    • Go to next step: If none of the conditions exist 
  2. Ignition OFF, and all vehicle systems OFF, it may take up to 2 minutes for all vehicle systems to power down. Disconnect the harness connector at the B75C Multifunction Intake Air Sensor.
  3. Test for less than 5 Ω between the low reference circuit terminal 3 and ground.
    • If 5 Ω or greater 
    1. Ignition OFF, disconnect the harness connector X1 at the K20 Engine Control Module.
    2. Test for less than 2 Ω in the low reference circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K20 Engine Control Module.
    • Go to next step: If less than 5 Ω 
  4. Ignition ON.
  5. Test for 4.8 - 5.2 V between the 5 V reference circuit terminal 2 and ground.
    • If less than 4.8 V 
    1. Ignition OFF, disconnect the harness connector X3 at the K20 Engine Control Module.
    2. Test for infinite resistance between the 5 V reference circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for less than 2 Ω in the 5 V reference circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K20 Engine Control Module.
    • If greater than 5.2 V 
    1. Ignition OFF, disconnect the harness connector X3 at the K20 Engine Control Module, ignition ON.
    2. Test for less than 1 V between the 5 V reference circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K20 Engine Control Module.
    • Go to next step: If between 4.8 - 5.2 V 
  6. Verify the scan tool BARO Sensor 2 parameter is greater than 4.7 V.
    • If 4.7 V or less 
    1. Ignition OFF, disconnect the harness connector X3 at the K20 Engine Control Module.
    2. Test for infinite resistance between the signal circuit terminal 4 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the K20 Engine Control Module.
    • Go to next step: If greater than 4.7 V 
    7. NOTE:

    If the signal circuit is shorted to a voltage the ECM or the sensor may be damaged.

  7. Connect a 3 A fused jumper wire between the signal circuit terminal 4 and the low reference circuit terminal 3.
  8. Verify the scan tool BARO Sensor 2 parameter is less than 0.2 V.
    • If 0.2 V or greater 
    1. Ignition OFF, remove the jumper wire, disconnect the harness connector X3 at the K20 Engine Control Module, ignition ON.
    2. Test for less than 1 V between the signal circuit terminal 4 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V
    3. Ignition Off
    4. Test for less than 2 Ω in the signal circuit end to end.
      • If 2 Ω or greater, repair the open or high resistance in the circuit.
      • If less than 2 Ω, replace the K20 Engine Control Module.
    • Go to next step: If less than 0.2 V 
  9. Test or replace the B75C Multifunction Intake Air Sensor.
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