Diagnostic Procedure

WARNING: This page is about a different car, the 2005 Jeep Liberty. However, it is still accessible from the selected car via links, so may be relevant.

DIAGNOSTIC PROCEDURES - ENGINE CRANKS BUT WILL NOT START

TEST	ACTION	APPLICABILITY
1	NOTE: The ECM must have proper power and ground connections for the following tests to be valid. Refer to CHECKING THE ECM POWER AND GROUNDS in the symptom list. Turn the ignition on.With the DRBIII®, read the ECM DTCs.Does the DRBIII® display any ECM DTCs?Yes --> Refer to ECM DTC.Perform NO START VERIFICATION - VER-1 .No --> Go To 2	All
2	Turn the ignition on. With the DRBIII®, read the SKIM DTCs. Does the DRBIII® display any SKIM DTCs? Yes --> Refer to appropriate test for problems related to SKIM DTC. Perform NO START VERIFICATION - VER-1 . No --> Go To 3	All
3	Using a temperature probe, check the vehicle temperature near the ECT Sensor. Turn the ignition on. With the DRBIII® in Sensors, read the ECT Sensor temperature. Compare the temperature probe reading with the DRBIII® reading. Are the two readings within 10°C of each other? Yes --> Go To 4 No --> Repair as necessary. Perform NO START VERIFICATION - VER-1 .	All
4	NOTE: Prior to performing this test, be sure to check the Glow Plug Relay operation. Refer to CHECKING GLOW PLUG OPERATION for the related symptom(s). Refer to the Service Information and check the Glow Plugs for proper operation.Are the Glow Plugs operating properly?Yes --> Go To 5No --> Repair as necessary.Perform NO START VERIFICATION - VER-1 .	All
5	Inspect the fuel system lines for restrictions, leaks or other problems. NOTE: Refer to the Service Information to ensure that the fuel system is properly primed. An unprimed system or excessive air in the supply system will cause a no-start condition. Is there any evidence of problems? Yes --> Repair as necessary. Perform NO START VERIFICATION - VER-1 . No --> Go To 6	All
6	Turn the ignition off. Attempt to start the engine, if the engine will not start, crank the engine for several seconds while monitoring the DRBIII®. With the DRBIII® in Sensors, read the Cam Position Sensor RPM. Does the DRBIII® display a steady CMP Sensor RPM approximately one half the speed of Engine RPM? Yes --> Go To 7 No --> Using the Service Information, check the wiring and connectors related to the CMP Sensor. If OK., replace the CMP Sensor. Perform NO START VERIFICATION - VER-1 .	All
7	Turn the ignition off. Attempt to start the engine, if the engine will not start, crank the engine for several seconds while monitoring the DRBIII®. With the DRBIII® in Sensors, read the Engine RPM. Does the DRBIII® display a steady CKP Sensor RPM approximately double the speed of the CMP RPM? Yes --> Go To 8 No --> Using the Service Information, check the wiring and connectors related to the CKP Sensor. If OK., replace the CKP Sensor. Perform NO START VERIFICATION - VER-1 .	All
8	Inspect the fuel supply for contamination. Is the fuel contaminated? Yes --> Refer to the Service Information to remove and replace fuel throughout the fuel system. Perform NO START VERIFICATION - VER-1 . No --> Go To 9	All
9	Refer to the Service Information to ensure the Engine Drive Belt/Chain is installed correctly and the camshaft and crankshaft gears are timed correctly. Were any problems found? Yes --> Repair as necessary. Perform NO START VERIFICATION - VER-1 . No --> Replace and program the Engine Control Module in accordance with the Service Information. Perform NO START VERIFICATION - VER-1 .	All