The check engine light on your Dodge Caravan model is designed to warn of possible problems in one or more of the vehicle systems. The first generation of on-board diagnostics (OBD I) used during the early 1980s on your Caravan, had a limited ability to monitor a few number of circuits. However, on-board diagnostic generation two (OBD II) has grown into a more sophisticated system.
The OBD II will trigger the check engine light or malfunction indicator light (MIL) on your Caravan once a problem has been detected and occurred a second time. If the light stays on, once you start the vehicle, the problem is not critical but should be repaired. A check engine light that stays on for a short period and then disappears might be an indication of an intermittent problem. However, if the computer system on your Caravan flashes this light as you drive, says James E. Duffy in Modern Automotive Technology, it is alerting you of a critical problem that may damage your catalytic converter and should be diagnosed as soon as possible.
New OBD II systems have the capacity to not only monitor a great number of circuits in different systems, but can pinpoint the nature of the failure, the specific circuit and possible component that may be involved in the failure. Your Caravan’s computer uses an array of sensors and actuators through out the vehicle to monitor and operate components. Once a sensor, actuator or circuit begins to behave out of predetermined parameters, the computer’s memory stores a code identifying the particular failure and turns the check engine light on.
When you see the warning light on, you can retrieve the code(s) by connecting a scan tool to the data link of the computer system of your vehicle. Depending on the sophistication of the tool, you will not only know the trouble code, but the circuit where the failure occurred, the component in question, and, in some cases, a series of values and instructions to troubleshoot the circuit or component. This may involve testing a camshaft or crankshaft misalignment, fuel injector malfunction, catalyst monitor failure or power steering problems.
Trouble codes are alphanumeric values similar to this: P 0243. The scan tool instruction manual or your vehicle service manual will give help you translate this number and point you to the nature of the failure on your Dodge Caravan.
