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Home >> Chevrolet >> 2017 >> Spark LT, Automatic CVT Trans >> Repair and Diagnosis >> External Pages >> Different car >> Section 61 (Engine Cooling System) >> Diagnostic Information and Procedures >> DTC P0480, P0481, P0691, P0692, P0693, or P0694 >> Circuit/System Testing

Circuit/System Testing

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  1. Ignition OFF, disconnect all cooling fan relays, ignition ON.
    2. NOTE:

    The following tests must be performed on all three fan relay circuits.

  2. Verify that a test lamp illuminates between ground and a relay coil ignition circuit terminals listed below:
    • KR20C Cooling Fan Low Speed Relay terminal 86
    • KR20D Cooling Fan High Speed Relay terminal 86
    • KR20P Cooling Fan Medium Speed Relay terminal 86
    • If the test lamp does not illuminate and the fuse is good 
    1. Ignition OFF, remove the test lamp.
    2. Test for less than 2 Ω in the ignition circuit of the appropriate cooling fan relay, 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 
    1. Ignition OFF, remove the test lamp.
    2. Test for infinite resistance between the cooling fan relay ignition circuits and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the appropriate cooling fan relay.
    • Go to next step: If the test lamp illuminates 
  3. Remove the test lamp.
    4. NOTE:

    The following tests must be performed on all three fan relay circuits.

  4. Connect a DMM, set on the diode setting, between ground and a relay control circuit terminal listed below:
    • KR20C Cooling Fan Low Speed Relay terminal 85
    • KR20D Cooling Fan High Speed Relay terminal 85
    • KR20P Cooling Fan Medium Speed Relay terminal 85
  5. Verify the DMM reading is greater than 2 V or displays O.L with the Cooling Fan Relays commanded OFF.
    • If 2.5 V or less 
    1. Ignition OFF, disconnect the X1 harness connector at the K20 Engine Control Module.
    2. Test for infinite resistance between the appropriate relay coil 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.
    • Go to next step: If greater than 2.5 V or displays O.L. 
  6. Command the cooling fan ON at high speed with a scan tool.
  7. Verify the DMM reading is less than 1 V at the cooling fan relay terminals listed below:
    • KR20C Cooling Fan Low Speed Relay terminal 85
    • KR20D Cooling Fan High Speed Relay terminal 85
    • KR20P Cooling Fan Medium Speed Relay terminal 85
    • If 1 V or greater 
    1. Ignition OFF, disconnect the X1 harness connector at the K20 Engine Control Module, ignition ON.
    2. Test for less than 1 V between the appropriate cooling fan relay control circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • Go to next step: If less than 1 V.
    3. Ignition OFF.
    4. Test for less than 2 Ω in the appropriate cooling fan relay 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 K20 Engine Control Module.
    • Go to next step: If less than 1 V 
  8. Test or replace the appropriate cooling fan relay.
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