Circuit/System Description
WARNING: This page is about a different car, the 2009 Pontiac Torrent and 2009 Chevrolet Equinox. However, it is still accessible from the selected car via links, so may be relevant.
The engine control module (ECM) has a 5-volt reference buss for each 5-volt reference circuit. The circuits are called 5-volt reference 1 and 5-volt reference 2. Each bus provides a 5-volt reference for more than one sensor. A fault condition on one 5-volt reference circuit will affect the other 5-volt reference circuits connected to that reference bus. The ECM monitors the voltage on the 5-volt reference busses.
The 5-volt reference 1 bus provides 5 volts to the following sensors:
- The exhaust gas recirculation (EGR) valve
- The manifold absolute pressure (MAP) sensor
- The fuel tank pressure (FTP) sensor
- The accelerator pedal position (APP) sensor 2
- The engine oil pressure (EOP) switch
- The air conditioning (A/C) refrigerant pressure sensor
- The camshaft position (CMP) sensor
The 5-volt reference 2 bus provides 5 volts to the following sensors:
- The APP sensor 1
- The throttle position (TP) sensor 1 and 2
- The crankshaft position (CKP) sensor