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Home >> Cadillac >> 2010 >> DTS 4.6 9 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System & Fuel System - 4.6L - DTC P0351 To P2271 >> DTC P0351-P0358 >> Circuit/System Testing

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the appropriate ignition coil.
  2. Test for less than 5 Ω between the ground circuit terminal D and ground.
    • If greater than the specified range, repair the ground circuit for an open/high resistance.
  3. Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes. Test for less than 5 Ω between the low reference circuit terminal C and ground.
    • If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  4. Ignition ON, verify that a test lamp illuminates between the ignition voltage circuit terminal A and ground.
    • If the test lamp does not illuminate, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition voltage circuit fuse is open, test all components connected to the ignition voltage circuit and replace as necessary.
  5. Connect a DMM between the ignition control circuit terminal B and ground.
  6. Engine running, test for 0.050-0.150 volts between the ignition control circuit and ground.
    • If less than the specified range, test the ignition control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
    • If greater than the specified range, test the ignition control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  7. If all circuits test normal, test or replace the ignition coil.
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