Service engine soon light. scan code po44o - 1991 Chevrolet S-10

Service engine soon or check engine light? Engine light needs scanned for codes. Service engine soon is for oil changes and such. To get rid of service lights, turn the key on, press the gas pedal three times within five seconds. The light will flash. turn the key off. it's reset. At least check or change the oil and filter though.

The "Service Engine Soon" comes on when the ECM receives information from the engines sensors that exceeds normal acceptable operating parameters. The ECM will store a code (or codes) indicating which system(s) are out of tolerance and light the "Service Engine Soon" lamp. The technician will read the codes, diagnose and repair the condition(s), and reset the "Service Engine Soon" lamp. The lamp does NOT go out on its own (in most cases), once repairs are made. There is a scan tool that is used to clear the stored codes that allows the lamp to go out. It is therefore possible that you may already have fixed the condition that set your light to on. Or not. The whole purpose of the lamp was to help avoid the kind of "hit and miss" repair methodology that you have employed so far. Many feel the need to try this as they fear the costs of a professional mechanic reading the codes and the cost of repairs. Fortunately, there are less costly options available. Many of the large auto parts chains will read the "Service Engine Soon" codes for you at no cost. They will tell you what codes are present and you can decide if you (or someone you know) can perform repairs or if you need a pro to check things out. They do NOT, normally, perform resets of the lamp as this has potential liability issues for them. If you need the lamp reset after repairs are made, you have two options; pay the pro, or buy a scan tool that has the ability to reset the light. Not all do. The cheaper units are only code READERS. Be careful when you buy. But if you watch for sales, you can usually get a low-cost scan tools that can read and reset codes for around $40.00. Good luck.

Stop at an autozone, napa, etc parts store and have them scan for codes to point you in the right direction. They will scan it for free, and advise of most common reason and part required to fix it. If not sure after scan, get back to me/us for advice and post the codes they told you were present.

Error Code: P0154
Description:
Heated Oxygen Sensor (HO2S) 1 , Bank 2 - No Activity Detected
Problem areas:
- Wiring.
- Open circuit in signal wire, between Heated Oxygen sensor 1, Bank 2 and ECM. (Must check and confirm)
- Heated oxygen sensor (HO2S).
- Engine control module (ECM).

have it scanned then decide depending on the code

The service vehicle is not the same as the service engine light in that the service vehicle light has to do with the body control module,(BCM).You have to get the codes read for the BCM and any other module with the scan tool.I`m not sure if Auto Zone can read the BCM codes.Not all scan tools are able to read all the modules in a vehicle.Hope this helps.Good luck.

THE SERVICE SOON LIGHT IS DIFFERENT FROM THE SERVICE ENGINE SOON LIGHT. MINES ARE ALSO ON AS WE SPEAK . I THINK I NEED TO SERVICE MY ABS BRAKES. WHEN YOU PUT YOUR CAR ON THE SCAN IT SCAN ENGINE CODES

Need to have sombody with a scan tool scan your vehicle, which will give you a dtc (dianostic trouble code) and determine what is cause the service engine soon light to come on

Hello and thank you for using FixYa!

The service engine soon light comes on when a fault is detected in the emission system. The service engine soon light is the same thing as a check engine light. A scan tool will be needed to get the code for the failure, so the proper repairs can be made.

Thanks Jay!

wandeeful: what has occurred, is something within the powertrain management system had malfunctioned. It may had occurred even for a brief moment. There will be a code stored in the computer which will tell what had tripped the light.
Once the scan is completed, then what need to be done will be known.
You can get the car scanned for free at
Auto Zone or "O" Reiley's