Test Description

The numbers below refer to the step numbers in the diagnostic procedure.

1. 4
   
   This step tests for Ignition 1 voltage supply to engine control module (ECM).
2. 6
   
   This step tests 12-volt reference circuit to CKP sensor and CMP sensor. 12-volt reference circuit for CKP sensor and CMP sensor is connected internally within ECM. If 12-volt reference circuit is shorted to ground, engine will not start and no engine speed will be indicated on scan tool.
3. 7
   
   If there is high resistance in signal or low reference circuits of CKP sensor, Engine Speed parameter on scan tool will display a value more than zero. It will not be an accurate measure of engine speed, and can cause an NO-START - ENGINE CRANKS OKAY condition.
4. 8
   
   If there is fuel in engine oil, fuel may be leaking from fuel injector or fuel injection pump into crankcase.
5. 9
   
   If fuel system will not even briefly prime to 10 psi and will not start, check valve in fuel filter/heater element housing is stuck open.
6. 10
   
   This step determines if fuel system is bleeding down causing a no-start. Fuel pressure will slowly drop to zero psi, but should still be above 8 psi for 10 seconds after pressurizing fuel system.
7. 12
   
   This step determines if problem is a stuck open or broken fuel injector. If fuel vapors come out of any glow plug holes, excessive fuel is being sent into a cylinder, and not being distributed to all fuel injectors.
8. 13
   
   The engine will not run without an actual fuel rail pressure more than 1450 psi (10 MPa).
9. 15
   
   If no-start condition takes place in cold operating temperatures, 35-40°F (2-4°C) or colder, a glow plug system failure may cause no-start condition.
10. 17
    
    In some cases, no compression, possibly with excessive fuel, in a single cylinder can cause a no-start.