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Home >> Chevrolet >> 2021 >> Blazer RS, FWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 11 (Engine Controls And Fuel - 2.5L (LCV) - Diagnostic Information And Procedures (2 Of 2)) >> Diagnostic Information and Procedures >> DTC P1516, P2101, P2119, or P2176 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.
  1. Ignition/Vehicle - Off
  2. Verify the following conditions do not exist:
      WARNING:

      Turn OFF the ignition before inserting fingers into the throttle bore. Unexpected movement of the throttle blade could cause personal injury.

    • The throttle blade has not reached the closed position after the engine has been turned off.
    • The throttle blade is not closed by the spring.
    • The throttle blade is binding in open or closed position.
    • If a condition exists 

      Replace the component: Q38 Throttle Body

    • Go to next step: If no condition exists 
    3. NOTE:

    Disconnecting the component electrical connector causes additional DTCs to set.

  3. Disconnect the electrical connector: Q38 Throttle Body
  4. Ignition - On / Vehicle - In Service Mode
  5. Test for 5 to 8 V between the test points:
    • Control circuit terminal 1/A & Ground
    • Control circuit terminal 2/B & Ground
    • If less than 5 V 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector: X2 @ K20 Engine Control Module
    3. Test for infinite resistance between the test points:
      • Control circuit terminal 1/A @ Component harness & Ground
      • Control circuit terminal 2/B @ Component harness & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    4. Test for less than 2 ohms between the test points:
      • Control circuit terminal 1/A @ Component harness & The other end of the circuit @ Control module harness
      • Control circuit terminal 2/B @ Component harness & The other end of the circuit @ Control module harness
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Replace the component: K20 Engine Control Module
    • If greater than 8 V 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector: X2 @ K20 Engine Control Module
    3. Ignition - On / Vehicle - In Service Mode
    4. Test for less than 1 V between the test points:
      • Control circuit terminal 1/A @ Component harness & Ground
      • Control circuit terminal 2/B @ Component harness & Ground
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • If less than 1 V - Replace the component: K20 Engine Control Module
    • Go to next step: If between 5 and 8 V 
  6. Ignition/Vehicle - Off
  7. Disconnect the electrical connector: X2 @ K20 Engine Control Module
  8. Test for less than 2 ohms between the test points:
    • Control circuit terminal 1/A @ Component harness & The other end of the circuit @ Control module harness
    • Control circuit terminal 2/B @ Component harness & The other end of the circuit @ Control module harness
    • If 2 ohms or greater 

      Repair the open/high resistance in the circuit.

    • Go to next step: If less than 2 ohms 
  9. Ignition OFF, Set the DMM to the 40 V scale, select the Min/Max Recording Mode, and set the Peak Min/Max response time to 1 ms.
    10. NOTE:
    • The ignition must be OFF and the ECM completely powered down before testing each circuit or a lower voltage will be recorded. It may take up to 2 min for all vehicle systems to power down.
    • The DMM Min/Max Recording Mode and the response time of 1 ms must be reset after testing each circuit or a lower voltage will be recorded.
  10. Verify the Max voltage is within 3 V of B+ while using DMM Min/Max Recording Mode function on each control circuit listed below as the ignition is turned ON.
    • Control circuit terminal 1/A @ Component harness & Ground
    • Control circuit terminal 2/B @ Component harness & Ground
    • If not within 3 V of the battery voltage 

      Test or replace the component: K20 Engine Control Module

    • Go to next step: If within 3 V of the battery voltage 
  11. Test or replace the component: Q38 Throttle Body
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