Technical Service Bulletins

Buick No Longer Communicates

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BUICK Enclave TSB.jpg

While performing normal diagnostics it will be found that the power circuits, ground circuits, communication enable signal circuit and the GM LAN circuits going to the EBCM test good. This testing may lead to replacement of the EBCM. However, the concern may still be present after installing a new EBCM.

| Photo Credit: GM

Some owners of 2008-2015 Buick Enclave vehicles may note that the ABS and red brake lamp is on in the instrument panel. When trying to retrieve DTCs, the scan tool may not communicate with the EBCM. The scan tool will communicate with all other high and low speed GM LAN modules, and some may have set a U0121 DTC against the EBCM. While performing normal diagnostics it will be found that the power circuits, ground circuits, communication enable signal circuit and the GM LAN circuits going to the EBCM test good. This testing may lead to replacement of the EBCM. However, the concern may still be present after installing a new EBCM.

  1. If equipped with StabiliTrak, the yaw and lateral accelerometer (multi-axis) sensor or the steering wheel angle sensor supply voltage (circuit 2087, dark green) may have shorted and is pulling down the internal circuitry of the EBCM. Not all vehicles use circuit 2087 to supply voltage to the steering wheel angle sensor, so be sure to check service information for the specific vehicle. If circuit 2087 is backed out of the EBCM connector and communication returns, inspect for eight this circuit being shorted to ground or for a sensor concern. 
  2. A shorted WSS or WSS wiring could be the cause. Inspect the WSS wiring for any broken/shorted/chaffed circuit. If none are found, unplug the WSS  one at a time and see if communication returns. If so, repair and/or replace any wiring/connector and/or WSS issues.


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