DTC 72: EBTCM Serial Data Link: Notes

Fig 1: EBTCM Serial Data Link System Schematic

Courtesy of GENERAL MOTORS CORP.

Serial data link is an asynchronous link operating at 8192 bits per second. SERVICE ASR indicator light will illuminate and DTC 72 will set if EBTCM detects 3 consecutive serial data link messages being ignored due to errors in transmission.

Fig 2: DTC 72 Diagnostic Flow Chart

Courtesy of GENERAL MOTORS CORP.

1. Checks if Tech 1 scan tester can communicate with EBTCM. If PCM cannot communicate with EBTCM, it will display "Err" when EBTCM is selected for DTC display. See ENTERING DIAGNOSTICS (MANUAL DIAGNOSTIC MODE) under CENTRAL CONTROL MODULE DIAGNOSTICS .