PicoScope 7 Automotive
Available for Windows, Mac, and Linux, the next evolution of our diagnostic scope software is now available.
The information on this page is illustrative. It is not to be used for training purposes or as guidance or instruction. It is also incomplete. A full version of this content can be found in our PicoScope 7 Automotive software, which is downloadable from here.
The purpose of the test is to check the operation of the System Main Relay (SMR) within a third-generation Toyota Prius hybrid vehicle.
The HV Control Module (HVCM) uses the SMR to control the HV connections between the HV battery and the motor inverter. The HVCM monitors the HV current flow to ensure the HV inverter supply is correctly established, maintained, and shut down. This allows:
The SMR startup process is as follows:
The SMR shutdown process is as follows:
This help topic is subject to changes without notification. The information within is carefully checked and considered to be correct. This information is an example of our investigations and findings and is not a definitive procedure. Pico Technology accepts no responsibility for inaccuracies. Each vehicle may be different and require unique test settings.
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February 18 2022
I have a Toyota Alphard hybrid and it reads power resources p3004 it doesn’t start and the system main relay doesn’t allow power to pass the positive relay doesn’t allow power to go through the inverter the 220 DC voltage stops on positive main relay