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 on the diagnostic procedures.

4 - This step tests for an ignition 1 voltage supply to ECM.
6 - This step tests the 12-volt reference circuit to the CKP sensor and CMP sensor. The 12-volt reference circuit for the CKP sensor and CMP sensor is connected internally within the ECM. If the 12-volt reference circuit is shorted to ground, engine will not start and no engine speed will be indicated on scan tool.
8 - If there is fuel in the engine oil, fuel may be leaking from the fuel injector or fuel injection pump into the crankcase.
9 - If fuel system will not even briefly prime to 10 psi and will not start, the check valve in the fuel filter/heater element housing is stuck open. See Figure.
10 - This step determines if fuel system is bleeding down causing a no-start. The fuel pressure will slowly drop to zero psi, but should still be greater than 8 psi, 10 seconds after pressurizing the fuel system.
12 - This step determines if problem is a stuck open or broken fuel injector. If fuel vapors come out of any of the glow plug holes, excessive fuel is being sent into a cylinder and not being distributed to all of the fuel injectors.
13 - The engine will not run without an actual fuel rail pressure more than 1450 psi (10 MPa).
15 - If the no-start condition takes place in cold operating temperatures, 35-40°F (2-4°C) or colder, a glow plug system failure may cause the no-start condition.
17 - In some cases, no compression, possibly with excessive fuel, in a single cylinder can cause a no-start.