P1649 OBD Code Definition:
Data Bus Powertrain Missing message from ABS Control Module
P1649 OBD Code Description:

Possible Symptoms

• Malfunction Indicator Light (MIL) ON

Possible Causes

• Fault Code(s) stored in Brake Electronics (J104)
• Communication Error with Brake Electronics (J104)

Possible Solutions

• Check Brake Electronics (J104) for Fault Codes
• Check Communication with Brake Electronics (J104)
  • See Measuring Value Blocks (MVB)