Engine Cranks But Does Not Run

Engine Cranks But Does Not Run

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description

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.

Diagnostic Aids

If the engine cranks but does not run condition occurs only in cold ambient temperatures, it may be due to ice blockage at the fuel pickup in the fuel tank-This will be indicated by a high vacuum in the supply lines while cranking and the problem will disappear after the vehicle is brought into the service bay. This condition may also cause the vehicle to start and stall, or to start but have no acceleration

Reference Information

Schematic Reference

Engine Controls Schematics (LGH or LML) [1][2]Electrical Diagrams

Connector End View Reference

Component Connector End Views 1-2 Shift Solenoid (SS) Valve (M30)

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Special Tools

CH-48027 Digital Pressure Gauge

Circuit/System Verification

1. If DTCs P0090, P0191, P0192, P0193, P0335, P0336, P0340, P0601, P0602, P0606, P0609, P060B, P061C, P062F, P0641, P064C, P0651, P0697, P06A3, P06D2, P2295 or P2296, P2510, or P2610 are set, diagnose those DTCs first.

2. Ignition ON, observe the scan tool VTD Fuel Disable parameter. The parameter should display INACTIVE.

• If the VTD Fuel Disable parameter displays ACTIVE, perform the Immobilizer System Component Programming Programming and Relearning.

3. Engine cranking, observe the scan tool Engine Speed parameter. The minimum cranking speed is 80 RPM on a cold engine and 125 RPM on a hot engine.

• If the cranking speed is slow, refer to Engine Cranks Slowly Engine Cranks Slowly

• If the engine speed is 0 RPM, refer to DTC P0335 P0335 or DTC P0336 P0336 for further diagnosis.

4. Inspect for the following conditions:

* Inadequate fuel in the fuel tanks.

* Fuel smell or leak-Refer to Fuel Leak Diagnosis Fuel System Diagnosis.

* Fuel contamination-Refer to Contaminants-in-Fuel Diagnosis Fuel System Diagnosis.

* A collapsed air intake duct or restricted air filter element.

5. Install the CH-48027 to the fuel rail service port, prime the fuel system to 68 kPa (10 psi), and crank the engine for 15 s.

• If the engine starts, refer to Fuel System Diagnosis Fuel System Diagnosis

6. Engine cranking, verify the fuel pressure gauge displays less than 6 in Hg.

• If the value displayed is greater than the specified range, refer to Fuel System Diagnosis Fuel System Diagnosis

7. Engine cranking, verify the scan tool Fuel Rail Pressure Sensor parameter is greater than 10 MPa.

• If less than the specified range, refer to Fuel System Diagnosis - High Pressure Side Fuel System Diagnosis

8. Verify the operation of the fuel system constant pressure regulator-Refer to Fuel Return System Diagnosis Fuel System Diagnosis. Perform steps 6-9.

9. Verify the following conditions do not exist:

* Exhaust system restricted-Refer to Symptoms - Engine Exhaust Symptoms - Engine Exhaust.

* Engine mechanical condition, for example, low compression-Refer to Symptoms - Engine Mechanical Symptoms - Engine Mechanical and Engine Compression Test Testing and Inspection.

• If you find any of the above conditions, repair as necessary.

Repair Verification

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.