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Home >> GMC >> 2017 >> Terrain SL, Gas >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Controls And Fuel - 2.4L (Lea) - DTC P0340 To DTC P2635 And Diagnostic Information And Procedures >> Diagnostic Information and Procedures >> DTC P15A1: Fuel Economy Mode Switch Performance >> Circuit/System Testing
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Circuit/System Testing

NOTE:

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

  1. Ignition OFF, disconnect the X1 harness connector at the S112 Fuel Economy Mode Switch.
  2. Test for less than 5 Ω between the ground circuit terminal 1 of the harness connector and ground.
    • If greater than the specified range, test the ground circuit for a high resistance and repair as necessary.
  3. Measure between the 5 V reference voltage circuit terminal 3 of the switch and signal circuit terminal 4 of the switch for 266 - 294 Ω with a DMM.
    • If the DMM does not measure between 266 - 294 Ω, replace the S112 Fuel Economy Mode Switch.
  4. Measure between the 5 V reference voltage circuit terminal 3 of the switch and the ground circuit terminal 1 of the switch for 1, 414 - 1, 562 Ω with a DMM.
    • If the DMM does not measure between 1, 414 - 1, 562 Ω, replace the S112 Fuel Economy Mode Switch.
  5. With the fuel economy mode switch button depressed, measure between the 5 V reference voltage circuit terminal 3 of the switch and the ground circuit terminal 1 of the switch for 486 - 538 Ω with a DMM.
    • If the DMM does not measure between 486 - 538 Ω, replace the S112 Fuel Economy Mode Switch.
  6. Disconnect the X2 harness connector at the ECM.
  7. Measure the 5 V reference voltage circuit, between terminal 14 of the ECM harness connector and terminal 3 of the fuel economy mode switch harness connector, for less than 5 Ω.
    • If greater than the specified range, repair or replace the 5 V reference voltage circuit as necessary.
  8. Measure the signal circuit, between terminal 50 of the ECM harness connector and terminal 4 of the fuel economy mode switch harness connector, for less than 5 Ω.
    • If greater than the specified range, repair or replace the signal circuit as necessary.
  9. If all circuits test normal, replace the K20 ECM.
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