How to Clear Engine Codes for a Jeep Libertyby Jody L. Campbell
Manufactured in 2002, the Jeep Liberty has always integrated the second phase of on-board diagnostics (OBD II). This newer vehicle diagnostic system standardized the placement of the data link connector (DLC) and the diagnostic trouble codes (DTCs). This simplified the process of diagnosing faulty sensors or modules in the vehicle that communicate to the vehicle's computer system. When a faulty DTC is detected in the Jeep Liberty's computerized system, it will trigger the "Check Engine Light" (also known as the malfunction indicator light or MIL), indicating an engine code has occurred.
Open the driver's side door of the Jeep Liberty and locate the diagnostic link connector (DLC) under the dash. It is located to the right of the steering wheel on the Liberty.
Plug the pocket scanner into the DLC and then turn the ignition key to the accessory position. This will power up all the electrical controls without the engine running. The scanner will get its power from the battery in the Liberty and will not require being turned on.
Read the onscreen menu of the scanner. While there are many makes and designs of pocket scanners, they are generally fairly universal in terms of operation. Most will feature a few options on the menu that you can scroll between and press an enter key to activate the function. If you're having trouble operating yours, refer to the owner's manual.
Choose "Erase" as an option. On some models, there may even be an "Erase" key. Simply press the key if that is the case on your pocket scanner.
Wait until the onscreen menu has displayed "Command Sent" or has defaulted back to the main menu.
Start the engine to the Liberty to determine if the "Check Engine Light" is out. If so, the engine codes are cleared. If not, further diagnosis is required.
- Pocket scanners have dropped in price over the past few years and are widely available and quite handy for the do-it-yourself mechanic. You can also bring the Liberty to an auto parts store or neighborhood repair facility. Most of these places will offer to scan and clear the engine codes for free.
- Some mechanics might suggest disconnecting the negative battery terminal for five minutes or so to clear the engine codes on your Liberty. While this will indeed clear the engine codes, understand if you have a theft-deterrent radio system or a car alarm on your Liberty, you're going to erase important codes for those systems as well. They will need to be reprogrammed, and unless you have the codes and the know-how, it'll be the dealer doing it for a hefty charge.
- You should never clear a code without properly diagnosing what the code is and having it fixed. The computer in your Liberty is self-diagnosing; and when you clear the codes, it simply goes through a relearning phase. Once it has communicated with all the sensors and modules, it will know whether the problem has been solved or not. In addition, while the computer is relearning, fuel-to-air ratio will not be monitored. This can cause less fuel efficiency, operational problems and damage to other components down the line.
- Most states that impose vehicle emissions, as part of the state inspection for the vehicle, will detect if the computer has recently been reset and fail the vehicle until the computer is ready. In most cases, once the computer is ready, it will re-trip the engine code, and the "Check Engine Light" will come back on.
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