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Home >> Chevrolet >> 2017 >> SS Automatic Trans >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls And Fuel - 6.2L (LS3) - Diagnostic Information And Procedures >> Diagnostic Information and Procedures >> DTC P0685, P0689, P0690, or P1682: Engine Controls Ignition Relay, Ignition 1 Switch Circuit 2 >> Component Testing
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Component Testing

Relay Test

  1. Ignition OFF, disconnect the KR75 Engine Controls Ignition Relay.
  2. Test for 70 - 110 Ω between terminals 85 and 86:
    • If less than 70 Ω or greater than 110 Ω 

      Replace the KR75 Engine Controls Ignition Relay.

    • If between 70 - 110 Ω 
  3. Test for infinite resistance between the terminals listed below:
    • 30 and 86
    • 30 and 87
    • 30 and 85
    • 85 and 87
    • If less than infinite resistance 

      Replace the KR75 Engine Controls Ignition Relay.

    • If infinite resistance 
  4. Install a 20 A fused jumper wire between relay terminal 85 and 12 V. Install a jumper wire between relay terminal 86 and ground.
  5. Test for less than 2 Ω between terminals 30 and 87.
    • If 2 Ω or greater 

      Replace the KR75 Engine Controls Ignition Relay.

    • If less than 2 Ω 
  6. All OK.