The total repair cost will vary based on the condition of your vehicle and the number of repairs needed to fix your symptom. Proper diagnosis will save you money by finding the exact repairs needed to fix your car right the first time.
A faulty oxygen sensor is one of the most common causes of a check engine light. Symptoms may include a decrease in fuel mileage, hesitation or misfiring from the engine, rough idling or even stalling. A faulty sensor may cause the vehicle to fail an emissions test.
Any time there is an emissions fault the check engine light will be displayed. The purpose of the check engine light is to inform the driver that an emission related fault has been found, and that there are on-board diagnostic (OBD) trouble codes stored in the powertrain or engine control module. Additionally, since the emissions systems are so intertwined into engine control and transmission control systems, symptoms may include nearly any sort of drivability concerns. This may include harsh shifting, failure to shift, hesitation on acceleration, jerking, engine failure to start or run, loss of power, or any number of other drivability issues.
Due to the nature of electrical systems on modern vehicles, the range of problems these can cause are nearly limitless. However, there is a way to categorize them in two ways. Permanent and intermittent problems. Permanent problems appear and remain. This may be the vehicle will not start, the radio does not work, or the door chime will not turn off among many, many others. These problems are more straight-forward to diagnose since they present themselves at all time. This means there will always be a fault to find. Intermittent electrical problems, however, can be difficult or impossible to locate, since they appear then disappear without warning. The best case scenario for an intermittent issue is when replicating the problem is easily accomplished and understood. This allows a technician to make an issue semi-permanent, allowing them to find the fault. Other issues that come and go without warning and cannot be replicated on demand must occur when the technician is servicing the vehicle, otherwise there is no problem to correct. It is most important to understand that electrical system faults always require inspection, and can include the vehicle working in any manner, or not working at all.
Like we noted in the last section, general diagnosis symptoms are the most vague of the bunch. There are several diagnostic spectrums, electrical diagnosis, drivability diagnostics, engine diagnostics, transmission diagnostics, and the list could continue for about 5 or 10 more spectrums of diagnostics. The most important take-away here, is that general diagnostics are diagnostics that have no other spectrum in which they fit, or the problem is unknown. This means that any vehicle left outside of a repair facility with the keys and an authorization to perform diagnosis will be diagnosed under the general diagnosis spectrum.
When the Check Engine Light comes on, you may experience engine performance issues such as poor acceleration, rough idling, or an engine that won't start. In some cases, no abnormal symptoms will be experienced. Other systems like the transmission or ABS can cause the Check Engine Light to illuminate and lights for those systems can come on at the same time. Similar lights may say "Check Engine Soon", "Malfunction Indicator Light" or just "Check". In rare case the engine can overheat.
When faced with a check engine light on your 1999 Ford Expedition, it's essential to approach the diagnosis methodically. Start by checking the gas cap; a loose or damaged cap is a common and easily fixable issue that can trigger the light. Next, utilize an OBD-II scanner to read any trouble codes from the vehicle's computer, as these codes will direct you to the specific problem area. After that, inspect the vacuum hoses for any signs of damage or disconnection, as leaks can significantly affect engine performance. Additionally, take a moment to examine the spark plugs; if they are worn or fouled, they may cause misfires that activate the check engine light. Finally, ensure that all essential fluid levels—such as oil, coolant, and transmission fluid—are adequate, as low levels can also lead to warning lights. By following these steps, you can effectively narrow down the cause of the check engine light and determine whether a simple fix or further investigation is needed.
When the check engine light illuminates in a 1999 Ford Expedition, it can be a source of concern for any DIY enthusiast. One of the most straightforward issues to check is the gas cap; a loose or damaged cap can easily trigger the light, so ensuring it is secure is a good first step. If the gas cap is not the culprit, consider inspecting the oxygen sensor, as a faulty sensor can lead to poor fuel efficiency and may require replacement. Additionally, issues with the catalytic converter can also cause the light to come on, often indicating a more serious problem that may need professional attention. Engine misfires, often caused by faulty spark plugs or ignition coils, can also trigger the check engine light, so checking these components is essential. Another potential issue is the mass airflow sensor, which plays a critical role in engine performance; if it malfunctions, it can lead to various performance issues. Lastly, don’t overlook the exhaust gas recirculation (EGR) valve, as clogging or malfunctioning can also trigger the light. Addressing these common issues promptly can help maintain your vehicle's performance and prevent further damage.
When the check engine light appears on your 1999 Ford Expedition, it serves as a critical alert that should not be ignored. The urgency of addressing this warning can vary significantly based on the nature of the underlying issue. For instance, if the light is flashing, it indicates a serious problem that demands immediate action; in such cases, turning off the engine right away is essential to prevent severe damage. Common causes for the light include a loose gas cap, faulty oxygen sensors, or issues with spark plugs and ignition coils, all of which can adversely affect your vehicle's performance and fuel efficiency. Ignoring these symptoms can lead to more significant complications, including costly repairs and diminished safety on the road. Therefore, whether you are a seasoned DIYer or a novice, it is crucial to diagnose and address the cause of the check engine light promptly to ensure your Ford Expedition remains in optimal condition and to avoid potential hazards.
Read about related problems experienced by other Ford Expedition drivers like you.
See what others are asking about their Ford Expedition. Get answers from RepairPal's community of auto experts and enthusiasts.
