Diagnostic Aids
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2018 GMC Yukon XL, 2018 GMC Yukon, 2018 Chevrolet Tahoe, 2018 Chevrolet Suburban, and 2018 Cadillac Escalade ESV. However, it is still accessible from the selected car via links, so may be relevant.
Low voltage or a momentary loss of power or ground to the ECM may cause a DTC to set. Verify the following:
- The battery cables are clean and tight and the battery is fully charged. Refer to Battery Inspection/Test .
- The ECM ground circuits do not have an open or high resistance.
- The ECM power circuits do not have an open, short to ground or high resistance.
Low voltage or a momentary loss of power or ground to the ECM may cause a DTC to set. Verify the following: