Circuit Description

WARNING: This page is about a different car, the 2002 Toyota Prius. However, it is still accessible from the selected car via links, so may be relevant.

The Hybrid Vehicle Electronic Control Unit (HV ECU) delivers data to the ECM for such items as power output required for the engine (required output), estimated torque produced by the engine, engine RPM of control target RPM and whether engine is in start mode or not. Based on required output and target RPM, the ECM calculates a target torque that is to be produced by the engine and compares it with the estimated torque. If estimated torque is very low compared with the target torque or engine start mode continues at engine RPM or for the duration calculated by engine coolant temperature, as abnormal condition is detected. DTC P3190 is set if following conditions continue at a fixed engine RPM or for a fixed length of time:

Communication with HV ECU is normal.
Engine RPM is a fixed value or more.
Engine start mode is not active.
Target torque is at a fixed value or more.
Ratio of estimated torque against target torque is less than 20 percent.

DTC P3191 is set if following conditions continue at a fixed engine RPM or for a fixed length of time:

Communication with HV ECU is normal.
Engine RPM is a fixed value or more.
Engine start mode is not active.

Possible causes are:

Air induction system malfunction.
Defective throttle body.
Improper fuel pressure.
Defective engine.
Defective Mass Airflow (MAF) meter.
Vehicle is out of fuel.
Defective Engine Coolant Temperature (ECT) sensor.
Defective crankshaft position sensor.
Defective camshaft position sensor.
Defective ECM.