Check Hybrid Powertrain Control Module for codes
Faulty Hybrid Powertrain Control Module
Engine Light ON (or Service Engine Soon Warning Light)
Control modules constantly monitor the vehicle for any condition which may adversely affect vehicle performance. If a condition is detected, the module sets a Diagnostic Trouble Code (DTC) and sends a serial data message to the Engine Control Module (ECM). The ECM sets a DTC to inform that the module has set a DTC. The serial data message sent by the module also contains a request for the ECM to illuminate the Malfunction Indicator Lamp (MIL).
The DTC will be set when the ECM receives a serial data message from the Hybrid Powertrain Control Module indicating that DTC has been set in the module.