Test Description
WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The numbers below refer to the step numbers in the diagnostic procedure.
- 2
If the fuel temperature is high enough to set DTC P0168, the fuel may be thin enough to cause this DTC to set. - 3
The engine will not start if the fuel leak is large enough. - 4
This step checks for an inaccurate fuel rail pressure sensor. - 5
This step checks for fuel leaks into the engine oil. - 6
This step checks for restriction in the fuel system between the fuel injection pump and the fuel tank. - 7
This test checks to see if the fuel injection pump is able to supply maximum fuel pressure at idle. The fuel injection pump should be able to create 145-158 MPa at idle. In extreme ambient or fuel temperatures, the fuel injection pump may only be able to generate a pressure at the low end of this range. - 8
This step checks for a restriction in the fuel system between the fuel injection pump and the fuel tank that may only cause symptoms at higher engine speed and load conditions. - 10
This step checks to see if the fuel rail pressure sensor wiring and ECM are functioning normally. - 12
If the vacuum is still too high in the fuel supply system after replacing the fuel filter, there is a restriction in the fuel supply lines or sending unit in the fuel tank.