The Engine Cranks but Does Not Run diagnostic table is an organized approach to identifying a condition that causes an engine not to start. The Engine Cranks but Does Not Run diagnostic table directs the service technician to the appropriate system diagnosis.
The Engine Cranks but Does Not Run diagnostic table assumes the following:
• | The battery is completely charged. Refer to Battery Inspection/Test in Engine Electrical. |
• | The engine cranking speed is within specifications. Refer to Engine Cranks Slowly in Engine Electrical. |
• | There is adequate fuel in the fuel tank. |
Inspect for the following conditions:
• | Mass air flow (MAF) is compared to a calculated mass air flow based upon the manifold absolute pressure (MAP), the throttle position (TP), and the engine RPM readings. A skewed or unresponsive MAP sensor at KEY ON will cause the predicted air flow value to be inaccurate. Compare the MAP and the TP sensor value to that of a known good vehicle. |
• | Faulty engine coolant temperature (ECT) sensor. Using a scan tool, compare engine coolant temperature with intake air temperature (IAT) on a completely cool engine. The engine coolant temperature should be within 3°C (5°F) of the intake air temperature. If not, refer to DTC P0128 . |
For an intermittent condition, refer to Intermittent Conditions .
The numbers below refer to the step numbers on the diagnostic table.
This step determines if the ignition relay is providing the listed fuses with voltage.
If all the Cylinder Injector Circuit Status parameters display Fault, this indicates a condition with the injector supply voltage circuit.
This step determines if the fuel pump is operating electrically.
Step | Action | Values | Yes | No | ||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |||||||||||||||||
2 |
Does the scan tool display DTC P0101, P0123, P0230, P0601, P0602, P1626, P1630, or P1631? | -- | Go to Step 3 | |||||||||||||||||
Important: Ensure that the fuses listed below are not open, before proceeding with this test. If you find a fuse that is open, go to step 4.
Does the test lamp illuminate on at least one side of all the fuses listed? | -- | Go to Step 4 | Go to Ignition Relay Diagnosis | |||||||||||||||||
Do all of the Cylinder Injector Circuit Status parameters display OK? | -- | Go to Step 5 | ||||||||||||||||||
With a scan tool, command the fuel pump ON. Does the fuel pump turn ON? | -- | Go to Step 6 | ||||||||||||||||||
6 |
Does the J 26792 spark? | -- | Go to Step 7 | |||||||||||||||||
7 |
Is the fuel pressure within the specified range when the fuel pump is operating? | 358-405 kPa (52-59 psi) | Go to Step 8 | Go to Fuel System Diagnosis | ||||||||||||||||
8 | Inspect for the following conditions:
Did you find and correct the condition? | -- | Go to Step 9 | Go to Diagnostic Aids | ||||||||||||||||
9 |
Does the engine start and continue to operate? | -- | Go to Step 10 | Go to Step 2 | ||||||||||||||||
10 |
Are any DTCs displayed? | -- | Go to Step 11 | |||||||||||||||||
11 | With a scan tool review the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK |