This Preliminary information communicates and issue with a customer concern of a SES MIL, Reduced Engine Power, Service Brake System, and/or Speed Limited message, a lack of brake assist making the brake pedal hard and DTC P0606. These issues can be caused by a low voltage conditions, but the EBCM incorrectly sets a DTC P0606 for a Control Module Processor Performance error. If the SI diagnostics are followed for DTC P0606 it can lead to a misdiagnosis and an incorrect repair. Dealers are advised to inspect for a low voltage condition and follow SI diagnostics for DTC P0562 "System Voltage Low". Engineering is trying to determine next steps in the resolution of this issue. It will likely be an update to SI or a change to the EBCM Calibration or both. Â
