ECU and OBC

[smtguy]

Question: Is any part of the OBC controlled by the ECU - or vice versa?

Thanks,

[TimU]

No. They are MOSTLY indepenant systems.
Refer to Pages 6581-0 to 6581-2 of the ETM.

The OBC receives signals from the Instrument Panel Cluster for:
* Fuel Rate from the Fuel Economy Guage AND Present Fuel Rate Output from the Motronic ECU.
* Vehicle Speed from the Speedometer
* Low Fuel Warning from the Fuel Guage and Fuel Tank Sender Switch

The Present Fuel Rate Output is the only direct integration with the the Motronic ECU.

However, a failed OBC relay can prevent power flow to the Main Relay, which will prevent the Motronic ECU from firing the injectors and coil spark.

[smtguy]

Tim - I have looked and am not finding the OBC relay. Is there another name that is used? Where is it located?
Thank you,
Scott