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Home >> Cadillac >> 2012 >> Escalade EXT >> Repair and Diagnosis >> External Pages >> Different car >> Section 1809 (Hybrid/EV Control System) >> Diagnostic Information and Procedures >> DTC P1A89 >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page is about a different car, the 2011 GMC Yukon, 2011 Chevrolet Tahoe, and 2011 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the X2 harness connector at the K1 accessory DC power control module.
  2. Ignition ON, command the accessory DC power control module Intermediate Voltage Control on the scan tool to turn On the 42 volt circuit.
  3. Test for 40-44 V between the 42 V reference output terminals 1 and 2 at the K1 accessory DC power control module.
    • If less than the specified range, replace the K1 accessory DC power control module.
  4. If the accessory DC power control module 42 V output tests normal, replace the K43 power steering control module.