Saab 900 Has A Check Engine Light

Common Causes of the Check Engine Light in Your Saab 900 and How to Resolve Them

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Reviewed by
Andrew Hajjar
Written by RepairPal Car Genius
Updated January 14, 2025
0%
40% chance it's the
Emissions System
0%
60% chance it's
Something else
The most common reasons a Saab 900 has a check engine light are an emissions system component, a sensor, or a catalytic converter.
  • Emissions System: A faulty emissions system component, such as an oxygen sensor or EGR valve, can lead to increased emissions and trigger the check engine light.
Proper diagnosis will determine the exact cause of your symptom, saving you money on unnecessary repairs. The diagnostic experts at RepairPal Certified shops have the right tools and experience to solve any symptom.

How much does it cost to fix a Saab 900 has a check engine light?

Common Repairs

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.

Troubleshooting Check Engine Light in a Saab 900

When troubleshooting the check engine light in your Saab 900, it's essential to adopt a systematic diagnostic approach that begins with the simplest solutions before progressing to more complex issues. Start by checking the O2 sensor, as this component is a common culprit for triggering the check engine light. If the sensor appears faulty, replacing it could resolve the issue. Next, utilize an OBD-II scanner to read the diagnostic trouble codes (DTC) stored in the vehicle's computer; these codes provide specific insights into what might be wrong. After addressing any identified codes, reset the check engine light to see if the problem persists. Additionally, inspect all electrical connections to ensure they are secure and free from corrosion, as poor connections can lead to erroneous signals. Don’t overlook the exhaust and intake systems; check for any leaks or blockages that could affect engine performance and trigger the warning light. By following this structured approach, you can effectively diagnose and potentially fix the issue, ensuring your Saab 900 runs smoothly.

What Could Cause the Check Engine Light to Illuminate in a Saab 900?

When the check engine light comes on in a Saab 900, it can be a source of concern for any DIY enthusiast. Understanding the common problems that may trigger this warning can empower you to take action. One frequent culprit is a faulty fuel injector, particularly in turbocharged models, which can lead to rough engine performance and increased exhaust smoke. Additionally, the vehicle's onboard computer may detect various faults, signaling that something requires immediate attention. This could range from issues with engine performance to problems within the transmission control system or emissions components. It's also important to consider the self-diagnosis warning light, which may illuminate during normal operation, indicating that the engine control module has stored fault codes that need to be checked. Other potential issues include loose or disconnected connectors, faulty wiring, and sensor malfunctions, such as a failing O2 sensor. By being aware of these common problems, you can take the first steps toward diagnosing the issue and ensuring your Saab 900 runs smoothly.

Why is the Check Engine Light On in a Saab 900?

When the Check Engine Light illuminates in your Saab 900, it serves as a critical warning that should not be ignored. This light often signifies underlying problems with essential components such as the emissions system, oxygen sensors, or even the catalytic converter. Ignoring these warnings can lead to decreased fuel efficiency, engine misfires, and potentially costly repairs down the line. For instance, a malfunctioning oxygen sensor not only affects your vehicle's performance but can also result in increased emissions, which may lead to failing an emissions test. Moreover, issues with the ignition cylinder can cause irregular engine behavior, posing safety risks while driving. Therefore, it is crucial to diagnose and address the root cause of the Check Engine Light as soon as possible to maintain your vehicle's performance and safety, ultimately saving you from more significant repairs and ensuring a smoother driving experience.

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Saab 900 Check Engine Light: Causes & Repair Guide