My service engine soon light stays on for a long period of time.

Service Engine Soon

If the Service Engine Soon indicator light stays lit after you've started the engine, the On Board Diagnostics system (OBD) has detected a malfunction of the vehicle emissions control system. Contact your authorized dealer as soon as possible.
If indicator light is blinking, an engine misfire may be occurring, which could damage your catalytic converter. Drive in a moderate fashion (avoid heavy acceleration and deceleration), and have your vehicle serviced immediately.*
The Service Engine Soon indicator light illuminates when the ignition is first turned on (prior to engine start) in order to test the bulb, as well as indicate whether the vehicle is ready for Inspection/Maintenance (I/M) testing.
Normally, the Service Engine Soon light will stay on until the engine is cranked, then turn itself off if no malfunctions are present. However, if after 15 seconds this light blinks eight times, it means that the vehicle is not ready for I/M testing.Check this link out Gary.
https://owner.ford.com/how-tos/vehicle-features/dashboard-instrument-cluster/warning-lamps-and-indicators.html

90% of the time a check engine light comes on it's the O2 sensor.

I suggest scanned the computer in order to know fault codes stored there, soud like a EVAp or Emissions failing.

If the Check Engine Light comes on in the city but goes off on the freeway, then the fault is present during city driving conditions. Pay attention to whether or not the vehicle runs or drives any differently when the Check Engine Light illuminates. If vehicle performance does change, drive the car as little as possible and take it to be checked by a service professional as soon as possible. If there is no change in vehicle performance, you can drive home, but have it inspected as soon as possible. In this condition, you run a risk of the vehicle dying or not starting.

* The Check Engine Light comes on and stays on.
If the Check Engine Light illuminates constantly during driving with no noticeable driving or performance problems, there is a permanent fault in the emission control system. When this happens, the computer that controls the emission system usually has a backup program that runs while the fault is present. (These backup programs are often referred to as "limp home" mode programs.) You should get the vehicle serviced as soon as possible, but in most cases, the vehicle will continue to operate, though you run a risk of it dying or not starting.



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Personally I would do a complete engine service, for example Air and Oil filters, Oil and Plugs (it may also be worth changing the coolant as I am not certain of the parameters that are monitored by the system) If the light still remains on then the most likely problem is the Engine Managment Unit or a sensor.

the anti-lock and traction lights will come on together if there is a common problem with the two, since they are closely related. may be a wheel speed sensor or something similar. the service engine soon light indicates a problem with the engine computer, can be anything from an emission system problem or an engine performance problem. all of these lights can come on with no apparent running problems on the car. the service vehicle soon light is basically a maintenance reminder, an oil change light. take the car into a shop and have the codes read for these lights.

drop by autozone and they will scan the codes for free (at least the last time i heard it was free) the people there are fairly knowledgable so they should be able to tell you why the light is on.

sometime it's a one off that triggers the light. after three cycles of the key when it hasn't encountered the same problem it will go out.

the light needs to be reset (free at an autoparts store) also; have them check your battery and, your alternator

I have a 1999 Rover with the 4.6. I bought a code reader for $150 and erased the code. Its paid for itself a hundred times. Did you fix the reason the service engine light problem first? Some auto part stores will read for you. I don't know if they will reset it for you at the same time. If problems not fixed the light will reappear in a very short period of time. Let me know if I can answer anything else. Good luck

hi,

had a 97 grand prix and could not get the light out for any period of time, It ended up being the exhaust gas sensor saying incomplete burn due to an intermittent miss, had to change plugs, plug wires and finally injector service but the light stayed out after that, that was a 3.8 V6, hopefully that helps

J

the service engine light is prob due to the oxygen sensor being damaged, not replace or you having the catalytic converter taken off---just messing with you. start at auto zone and have then do a free code read then go from there. you should troubleshoot the low fluid level switch for your brake fluid. unplug it and see if the light goes off and if it doesn't jump the two terminals on the harness. oh the car will have to be running. Let me know [email protected]