Test Description
WARNING: This page is about a different car, the 2005 Buick LaCrosse and 2005 Buick Allure. 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 table.
- 2:
This step determines if there is a DTC causing the no start condition.
- 3:
This step determines if the fuel pump is turning on. An audible sound can be heard at the fuel injector rail when the fuel pump is turned ON.
Engine Cranks but Does Not Run
| Step |
Action |
Values |
Yes |
No |
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Control Module (ECM) Connector End Views
or Engine Controls Connector End Views |
| 1 |
Did you perform the Diagnostic System Check - Vehicle? |
- |
Go to Step 2 |
Go to Diagnostic System Check - Vehicle
in Vehicle DTC Information |
| 2 |
- Crank the engine over for 15 seconds.
- Turn ON the ignition, with the engine OFF.
- Observe the Engine DTC information with a scan tool.
Does the scan tool display DTC P0118, P0201-P0206, P0335, P0336, P0337, P0338, P0351-P0356, P0601, P0602, P0604, P0606, P0627, P0628, P0629, P1629, P1630, P1631, or P2105? |
- |
Go to Diagnostic Trouble Code (DTC) List - Vehicle
in Vehicle DTC Information |
Go to Step 3 |
| 3 |
IMPORTANT:
- The Fuel Pump Relay Command parameter may not change from OFF to ON or ON to OFF when using the Fuel Pump output control.
- Additional DTCs may set when using the Fuel Pump output control.
With a scan tool, command the fuel pump ON.Does the fuel pump turn ON? |
- |
Go to Step 4 |
Go to Fuel Pump Electrical Circuit Diagnosis |
| 4 |
- Turn OFF the ignition.
- Install the J 34730-1A
Fuel Pressure Gage. See Special Tools
. Refer to Fuel Pressure Gage Installation and Removal
.
- Turn ON the ignition, with the engine OFF.
IMPORTANT:
- The Fuel Pump Relay Command parameter may not change from OFF to ON or ON to OFF when using the Fuel Pump output control.
- Additional DTCs may set when using the Fuel Pump output control.
- Command the fuel pump ON with a scan tool.
Is the fuel pressure within the specified range while the fuel pump is operating? |
380-410 kPa (55-60 psi) |
Go to Step 5 |
Go to Fuel System Diagnosis |
| 5 |
Inspect for the following conditions:
- A short to voltage in the signal circuit of the crankshaft position (CKP) sensor will cause the engine to stall or not start and a DTC will not set. Refer to DTC P0335
.
- Collapsed air intake duct between the mass air flow (MAF) sensor and the throttle body
- Restricted air filter element
- Test for water or alcohol contaminated fuel. Refer to Alcohol/Contaminants-in-Fuel Diagnosis (w/o Special Tool) or Alcohol/Contaminants-in-Fuel Diagnosis (w/Special Tool) .
- Spark plugs for being gas or coolant fouled-If the spark plugs are fouled, determine what caused the condition, refer to the following procedures:
- Inspect for a malfunctioning MAF sensor causing a no start or a stall after a start. If this condition is suspected, use the following procedure:
- Engine mechanical condition, for example, worn timing chain and gears, low compression-Refer to Symptoms - Engine Mechanical
in Engine Mechanical - 3.6L (LY7).
- Restricted exhaust system-Refer to Restricted Exhaust
in Engine Exhaust
- The engine coolant temperature (ECT) sensor is NOT close to the actual engine temperature. Refer to DTC P0125
.
Did you complete the action? |
- |
Go to Step 6 |
- |
| 6 |
- With a scan tool, clear the DTCs.
- Attempt to start the engine.
Does the engine start and continue to operate? |
- |
Go to Step 7 |
Go to Step 2 |
| 7 |
- Idle the engine.
- Allow the engine to reach operating temperature.
- Observe the DTC information with a scan tool.
Are there any DTCs that have not been diagnosed? |
- |
Go to Diagnostic Trouble Code (DTC) List - Vehicle
in Vehicle DTC Information |
System OK |