LEMON Manuals: Even more car manuals for everyone
Home >> Buick >> 2007 >> Lucerne CX >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 5 (Engine Controls And Fuel - 4.6L - DTC P0351 To DTC P2440) >> DTC P1682 >> Diagnostic Aids >> Circuit/System Verification

Circuit/System Verification

WARNING: This page is about a different variant/trim than selected.
  1. If DTCs P0685, P0689, 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.