How to Diagnose Engine Trouble in a 1997 Jeep 4.0
- 1). Consult your manual for the exact steps on how to use your scanner. The process is similar in spirit, but there are variations. Some differences are minimal, like button configurations. Other differences are operational, like whether or not the scanner self-activates and retrieves codes without a command being keyed in. Also, make note of where the OBD-II code descriptions are, as you will need to reference them later.
- 2). Open your driver-side door and look beneath the dashboard. Locate the diagnostic data link outlet. It contains 16 pin-receiving slots. This outlet will be uncovered, and it will be to the left of the steering column.
- 3). Hook your OBD-II scanner up to the data link outlet.
- 4). Turn the electrical system or the engine on. Which one depends on the scanner you own. Also, switch your scanner on if it does not switch itself on, and key in any needed "read" commands.
- 5). Look up the codes that appear on the scanner's read-out. You will need the scanner's manual for this. The scanner will differentiate between trouble codes and pending ones. Look up the trouble codes first, as they have occurred more often. Should your scanner not contain code definitions, you will need to locate that information online. Also, Chrysler has supplemental OBD-II codes that Jeep vehicles use. You will likely not find those codes in your manual.
- 6). Turn the Jeep off. Turn the scanner off and unhook it from the data link outlet. Pop the Jeep's hood, and use the trouble and pending codes as a launching point for further investigation.
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