Circuit Description
WARNING: This page does not describe the selected car, but rather 54 other vehicles, including the 1999 Oldsmobile Bravada, 1999 GMC Yukon, 1999 GMC Suburban, 1999 GMC Sonoma, and 1999 GMC Savana Special. However, it is still accessible from the selected car via links, so may be relevant.
The pump motor circuit is integral to EBCM. The EBCM energizes the relay within EBCM to supply battery voltage to high side of pump motor. When pump motor activation is required, EBCM grounds low side of pump motor.
Conditions for setting DTC:
- Vehicle speed at 8 MPH or greater.
- EBCM internal relay on.
- Pump motor commanded on and then off.
- High voltage from low side of pump motor for milliseconds when expected to be low.