2003 Cadillac Escalade EXTFACTORY OEM SERVICE PROCEDURE

Serial Data Power Mode: Notes

WARNING: This page is about a different car, the 2004 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.

On vehicles that have several control modules connected by serial data circuits, one module is the power mode master (PMM). On this vehicle the PMM is the DIM. The PMM receives 2 signals from the ignition switch.

To determine the correct power mode the PMM uses the following circuits:

  • Accessory voltage
  • Run/Crank voltage
2-Wire Ignition Switch Table

Ignition Switch Position Accessory (Ignition Accessory/Run) IGN 1 (Ignition Run/Crank) Power Mode Transmitted
Off 0 0 OFF/Awake or RAP
Start 0 1 Crank
Accessory 1 0 Accessory
Run 1 1 Run
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.