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Ron, ASE Certified Technician
Category: Volvo
Satisfied Customers: 36091
Experience:  35 years as a Automotive tech
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2002 Volvo S40 - check engine light constantly comes on. I

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2002 Volvo S40 - check engine light constantly comes on. I have had a tune up, new battery, new fuel pump, and new sensor. 130009 milage
JA: Does the light stay on, or does it blink?
Customer: When I leave service it stays off for a day and then comes back on. light then stays on. Sometime when I fill up with gas (using premium now) it will go off for a while.
JA: Are you fixing your S40 yourself? What have you tried so far?
Customer: No, I take it to Ghosein European Werks
JA: Anything else you want the mechanic to know before I connect you?
Customer: No.

Hello. My name is ***** ***** I am happy to assist you today. Give me just a moment to review your post, and I'll be right back with the help you need.

When your check engine light comes on the computer system detects a problem and will set and store a fault code and or codes. In order to determine what is failing we are going to need to know what the fault code and or codes are that are setting. Most auto parts stores such as Auto Zone will do a scan for you at no charge. If you can get the scan done and post back with them I will direct you from there as to the proper repair.

Customer: replied 4 months ago.
Have done that and they stated a tune up which I have done....this has been going on for 2 months

Okay can you tell me the actual fault code and or codes are that should be setting when the check engine light comes on?

Customer: replied 4 months ago.
I will have to check this out. This has been on going for 2 to 3 months I feel I have rebuilt the car.

If you can get me the actual fault code and or codes I can help you determine what has been missed here.

Customer: replied 4 months ago.
I will take it to an auto zone and see about fault code or codes again.

Okay post back when your ready and we can work from there.

Customer: replied 4 months ago.
will do.

Thank you, ***** ***** when your ready.

Customer: replied 4 months ago.
Will get back when I get info.

Okay sounds good.

Customer: replied 4 months ago.
Engine light went off when I put gas in my car (premium) stayed off for 3 days until I started using my A/C. Went to Auto
Zone, today and the error code read PO101 some sort of sensor that measures the volume and density entering the engine.

The common cause for the code P0101 to set on your S40 is usually caused by a failing Manifold Absolute Pressure (MAP) Sensor and in most cases if there are no intake air system leaks and or vacuum leaks then replacing the MAP will usually solve this code.

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