Contenu
- Grand Cherokees 1996 and Later
- Step 1
- Step 2
- Step 3
- Step 4
- Jeep Grand Cherokees Before 1996
- Step 1
- Step 2
- Tip
- Items you will need
Once a Jeep Grand Cherokees check engine light illuminates, it means the On-Board Diagnostic system has repeatedly detected an engine malfunction. A problem has to repeat itself several times before the Grand Cherokees On-Board Diagnostic system will give it a "fault" status. There are ways to troubleshoot the system, and that involves examining the fault codes. How to do that depends on the year the Grand Cherokee was manufactured.
Grand Cherokees 1996 and Later
Step 1
Open the drivers side door and plug your OBD-II scanners cable into the Grand Cherokees diagnostic outlet. This Data Link Connection will be located on the drivers sidde of the Jeep, beneath the steering wheel, somewhere between the left kick a panel and the gas pedal.
Step 2
Turn the Jeep Grand Cherokees electrical system on. You may have to also crank the engine, depending on the brand and type of OBD-II scanner you own. At this time, if you do not have a self-starting scanner, you will have to switch it on yourself. The procedure for operating a diagnostic scanner varies by brand, and it is always best to defer to the exact instructions contained in your scanners user manual.
Step 3
Look at your scanners screen. If your brand of hand-held is not preprogrammed to retrieve diagnostic codes, you will have to key a "scan" command. Some scanners have a dedicated button for this, and others require you interacting with menus.
Step 4
Reference your manual for the codes that come up. You will need to differentiate between what is a "pending" code, and what is a "fault" or "trouble." Fault codes trigger the check engine light, and pending codes do not.
Reference Chryslers supplemental OBD-II codes online (See Resources). Your scanners handbook will likely only have the generic OBD-II codes universal to all cars and light trucks after 1996. Once you have found all the definitions for the fault codes reported by your scanner, you can make an educated decision on whether to do the repairs yourself, or consult a professional mechanic.
Jeep Grand Cherokees Before 1996
Step 1
Get behind the Grand Cherokees wheel and slide your key into the ignition. Turn the key in the following pattern: On-Off-On-Off-On. You need to do this in 5 seconds or less for the Grand Cherokees computer to recognize it as a command.
Step 2
Grab a pen and paper and count the number times the check engine light flashes at you. It will be a code. Long pauses will be used to separate fault codes. The codes themselves are two digits. The first number will flash. There will then be a pause before the second number flashes. For instance, code 41 will be represented by four flashes, a pause, and then one pause.
Look up the Chryslers flash codes online (See References). Since the Grand Cherokees diagnostic system predates Environmental Protection Agency standardization, other manufacturers codes will not help. Once you have found definitions for the flash codes reported to you, you can figure out whether to take the Jeep to a garage.
Tip
- Chryslers owners manuals will neither have flash nor OBD-II code definitions.
Items you will need
- OBD-II scanner
- Pen
- Paper
