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Home >> Chevrolet >> 2018 >> Trax Premier, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 16 (Engine Controls And Fuel - 1.4L (LE2) - Diagnostic Information And Procedures (P0010-P06B6)) >> Diagnostic Information and Procedures >> DTC P0097, P0098, or P0099 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2018 Buick Encore. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:

You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

  1. Ignition Off, and all vehicle systems OFF, it may take up to 2 min. for all vehicle systems to power down. Disconnect the harness connector at the B75C Multifunction Intake Air sensor.
  2. Test for less than 5 Ω between the low reference circuit terminal 7 and ground.
    • If 5 Ω or greater 
    1. Disconnect the harness connector 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 or 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 
  3. Determine if the vehicle is equipped with Stop/Start, RPO KL9.
    • If vehicle is not equipped with Stop/Start, RPO KL9 

      Refer to Step 7.

    • Go to next step: If vehicle is equipped with Stop/Start, RPO KL9 
  4. Ignition OFF, disconnect the harness connector at the B75C Multifunction Intake Air sensor. Connect the test lamp between B+ and the MAF control circuit terminal 4.
  5. Ignition ON, the test lamp should be OFF. Engine Running, the test lamp should be ON.
    • If the test lamp is always ON 
    1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
    2. Test for infinite resistance between the control circuit 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 test lamp is always OFF 
    1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
    2. Test for 2 Ω resistance between the control circuit and ground.
      • 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 the test lamp turns ON and OFF 
  6. Refer to Step 8.
  7. Test for less than 5 Ω between the MAF sensor enable circuit terminal 4 and ground.
    • If 5 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 or high resistance in the circuit.
      • If less than 2 Ω, repair the open/high resistance in the ground connection.
    • Go to next step: If less than 5 Ω 
  8. Ignition On.
  9. Verify that a test lamp illuminates between the ignition circuit terminal 5 and ground.
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Ignition Off, remove the test lamp and remove the fuse for the ignition voltage circuit.
    2. Test for less than 2 Ω in the ignition voltage circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.
    • If the test lamp does not illuminate and the circuit fuse is open 
      NOTE:

      The ignition circuit may supply voltage to other components. Make sure to test all circuits and components for a short to ground that share the ignition circuit.

    1. Ignition Off, remove the test lamp, the fuse for the ignition voltage circuit, and disconnect all components on the circuit.
    2. Test for infinite resistance between the ignition voltage circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, test all components connected to the ignition circuit, replace as necessary.
    • Go to next step: If a test lamp illuminates 
    10. NOTE:

    The intake air temperature sensor 2 signal circuit is pulled up with low current voltage within the controller. Normally, a voltage can be measured on the circuit with a DMM, but the current will not be high enough to illuminate a test lamp.

  10. Verify the scan tool Intake Air Humidity Sensor parameter is less than 1%.
    • If 1% or greater 
    1. Ignition Off, disconnect the harness connector at the K20 Engine Control Module.
    2. Test for infinite resistance between the IAT 2 signal circuit terminal 1 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 less than 1% 
  11. Ignition Off, install a 3 A fused jumper wire between the IAT 2 signal circuit terminal 1 and the low reference circuit terminal 7.
  12. Ignition On.
  13. Verify the scan tool Intake Air Humidity Sensor parameter is greater than 99%.
    • If 99% or less 
      NOTE:

      If the signal circuit is shorted to a voltage the engine control module or the sensor may be damaged.

    1. Ignition Off, remove the jumper wire and disconnect the harness connector at the K20 Engine Control Module.
    2. Ignition On.
    3. Test for less than 1 V between the IAT 2 signal circuit terminal 1 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • Go to next step: If less than 1 V.
    4. Ignition Off.
    5. Test for less than 2 Ω in the signal 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 greater than 99% 
  14. Test or replace the B75C Multifunction Intake Air sensor.
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