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Home >> Hummer >> 2009 >> H3 Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls And Fuel - 3.7L - DTC P1400 To DTC P2635 >> DTC P1682 >> Circuit/System Verification
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Circuit/System Verification

  1. If DTCs P0685 or P0690 are set, diagnose those DTCs first.
  2. Ignition ON, engine OFF, observe the Ignition 1 Voltage Signal and the EC Ignition Relay Feedback Signal parameters on the scan tool. Both parameter values should display no more than 3 volts difference between the 2 parameters.
  3. Ignition OFF, observe the Ignition 1 Voltage Signal parameter on the scan tool. The parameter value should be 0 volts before the ECM powers down.