Circuit/System Verification

WARNING: This page is about a different car, the 2019 Buick Cascada, 2018 Buick Cascada, and 2017 Buick Cascada. However, it is still accessible from the selected car via links, so may be relevant.

Determine the device that is not communicating. Refer to Control Module U Code List .
Verify that DTC U0073, U2100, U0074, U0078, U1814, U2099, B1325, B1330, B1370, B1380, B1424, B1440, B1441, B1517, C0800, C0899, C12E1, P0560, or P0562 is not set.
- If any of the DTCs are set
  Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- Go to next step: If none of the DTCs are set
Verify that DTC U0125 and DTC U0126 are not set together.
- If both of the DTCs are set together
  Refer to Scan Tool Does Not Communicate with Chassis High Speed GMLAN Device .
- Go to next step: If both of the DTCs are not set together
Engine running for 10 s.
Ignition ON, engine OFF, verify that DTC U0100 - U02FF is not set.
- If the DTC U0100 - U02FF is set in any device, except the K17 Electronic Brake Control Module
  Refer to Circuit/System Testing.
- If the DTC U0100 - U02FF is set in the K17 Electronic Brake Control Module with any symptom byte, except symptom bytes 71, 72, and 74
  Refer to Circuit/System Testing.
- If the DTC U0100 - U02FF is set in the K17 Electronic Brake Control Module with symptom byte 71, 72, or 74 along with other DTCs set
  Diagnose all other DTCs first. Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- If the DTC U0100 - U02FF is set in the K17 Electronic Brake Control Module with symptom byte 71, 72, or 74 and without other DTCs set
1. Program the K17 Electronic Brake Control Module.
2. Verify the DTC does not set.
  - If the DTC sets, replace the K17 Electronic Brake Control Module.
  - Go to next step: If the DTC does not set
3. All OK.
- Go to next step: If the DTC U0100 - U02FF is not set
All OK.