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2008 CADILLAC CTS
3.6L V6•RWD•AUTOMATIC•gas
2 active safety recalls on this vehicle — view recalls
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Repairs0Labor494Torque4240Fluid8DTC1195Battery1Maintenance0Recalls2
P1633high severityPowertrain

Ignition Supply Power Circuit Low Voltage

on 2008 Cadillac CTS 3.6L V6 · RWD

What this code means

The PCM detected low voltage on its ignition supply power circuit. The ignition power circuit provides run/start voltage to the PCM.

Symptoms

  • Check Engine Light
  • Engine stalling
  • Poor performance
  • Intermittent no-start
  • Multiple erratic codes

Common causes

  • Faulty ignition switch
  • Loose ignition power connection
  • Blown fuse
  • Damaged wiring
  • Corroded ignition switch connector

Diagnostic steps

  1. Test voltage at PCM ignition power circuit
  2. Check ignition switch output
  3. Inspect ignition power fuse
  4. Test wiring for resistance
  5. Check connector at ignition switch

Repair notes

Check ignition switch, fuse, and wiring. Replace ignition switch if voltage output is low.

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