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 - P0300-MISFIRE DETECTED
| TEST | ACTION | APPLICABILITY |
|---|---|---|
| 1 |
NOTE:
If the ECM detects and stores a DTC, the ECM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the DRB at the same time the DTC is displayed.
NOTE:
Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC. With the DRBIII®, erase ECM DTCs.Test drive the vehicle and attempt to duplicate the problem.With the DRB, read ECM DTC's.Did this DTC set again?Yes --> Go To 2No --> Go To 5 |
All |
| 2 | Turn the ignition off. With the DRBIII®, perform the Cylinder Compression Test. Is the cylinder compression within specification for all cylinders? Yes --> Go To 3 No --> Repair as necessary in accordance with the Service Information. Perform ROAD TEST VERIFICATION - VER-2 . |
All |
| 3 | Turn the ignition off. With the DRBIII®, perform the Injector Quantity Test. Is the Injector Quantity within specification for all cylinders? Yes --> Go To 4 No --> Repair or replace as necessary in accordance with the Service Information. Perform ROAD TEST VERIFICATION - VER-2 . |
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| 4 | Turn the ignition off. Perform the INJECTOR LEAKAGE TEST in accordance with the Service Information. Were any problems found? Yes --> Repair or replace as necessary in accordance with the Service Information. Perform ROAD TEST VERIFICATION - VER-2 . No --> Test Complete. |
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| 5 |
WARNING:
WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
NOTE:
The conditions that set the DTC are not present at this time. The following list may help in identifying the intermittent condition. With the engine running at normal operating temperature, monitor the DRB parameters related to the DTC while wiggling the wiring harness. Look for parameter values to change and/or a DTC to set.Review the DTC When Monitored and Set Conditions. If possible, try to duplicate the conditions under which the DTC was set.Refer to any Technical Service Bulletins (TSB) that may apply.Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or partially broken wires.Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.Were any of the above conditions present?Yes --> Repair as necessary.Perform ROAD TEST VERIFICATION - VER-2 .No --> Test Complete. |
All |