LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Cadillac >> 2011 >> Escalade EXT >> Repair and Diagnosis >> External Pages >> Different car >> Section 1556 (Data Communication System) >> Diagnostic Information and Procedures >> DTC U1818 >> Circuit/System Testing
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Circuit/System Testing

WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, 2010 Chevrolet Silverado, and 2010 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect harness connector X1 of the APM and the EBCM.
  2. Test for less than 1.0 ohm between the APM and the EBCM on the following circuit terminals.
    • PTLAN + APM terminal 5 and EBCM terminal 33
    • PTLAN - APM terminal 1 and EBCM terminal 21
    • If greater than the specified range, test the circuit for an open/high resistance.
  3. Ignition OFF, disconnect harness connector X1 of the SDGM.
  4. Test for less than 1.0 ohm between the EBCM and the SDGM on the following circuit terminals.
    • PTLAN + EBCM terminal 34 and SDGM terminal 13
    • PTLAN - EBCM terminal 22 and SDGM terminal 11
    • If greater than the specified range, test the circuit for an open/high resistance.
  5. If the circuits test normal, replace the SDGM.
scientia non olet · About LEMON Manuals