F53 Service Engine Soon

dirko · 08-24-2008, 04:47 PM

Hi Ho: The "Service Engine Soon" light came on on our last trip. I can't detect anything out of the ordinary, but would still like to know why the light. So I bought a cheap Cen Tech OBD II code reader from Harbor Freight and after some looking found the connector on the right side of the steering column where it is almost impossible to access. After connecting the thing by feel I get the normal "OBD II" followed by "Link..." and nothing further. No error codes or diagnostic codes. So I tried the the reader on the Impala and it worked normally. I will go by Auto Zone tomorrow and see if they can read diagnostic codes. Meanwhile I tried to reset the "check engine soon" light by removing the battery connector for the truck, but nothing changes.

My questions are: Should the light be reset by removing the battery connector? Does this mean a possible failure of the OBD processor? Does anyone know where this processor is located?

Sorry for the long post and thanks for any help.
Dirk

dirko · 08-24-2008, 04:47 PM

Hi Ho: The "Service Engine Soon" light came on on our last trip. I can't detect anything out of the ordinary, but would still like to know why the light. So I bought a cheap Cen Tech OBD II code reader from Harbor Freight and after some looking found the connector on the right side of the steering column where it is almost impossible to access. After connecting the thing by feel I get the normal "OBD II" followed by "Link..." and nothing further. No error codes or diagnostic codes. So I tried the the reader on the Impala and it worked normally. I will go by Auto Zone tomorrow and see if they can read diagnostic codes. Meanwhile I tried to reset the "check engine soon" light by removing the battery connector for the truck, but nothing changes.

My questions are: Should the light be reset by removing the battery connector? Does this mean a possible failure of the OBD processor? Does anyone know where this processor is located?

Sorry for the long post and thanks for any help.
Dirk

porscheracer · 08-24-2008, 04:54 PM

"Service engine soon" codes are usually mileage triggered. Like a reminder to perform some servide task. When the task is completed, the tech resets the function.

Rocket Heart · 08-25-2008, 05:27 AM

Had the same problem with my first coach - 99 Monaco LaPalma F53 - it was always gas related. It seems they are very sensitive to changes. I was advise to try to stick with one brand of gas as much as I could - two at the most.

Also my gas cap had to be on just right or the light would come on. In the winter I put Stabil in it and the light would come on until I ran the tank out.

Hope that it's all the trouble you have and nothing major.

glarnold · 08-25-2008, 08:58 AM

Don't know whether it's helpful or not, but our Honda recently had that light come on. While having it serviced, I asked the tech about re-setting it. He showed me in the owner's manual where it said to use a combination of key off, holding in the odometer reset push switch, and turning the key on. It reset itself. Was totally surprised to see those directions in the owner's manual.

AFChap · 08-25-2008, 09:07 AM

As indicated, most "Service Engine" lights are triggered by mileage, and must be reset when the service (oil change, etc) is done. On the other hand, a "Check Engine" light is normally due to a fault code and can be triggered by something as simple as not getting the fuel cap on securely (or a spider web in the fuel vent tube like I had once!!) -- and will re-set itself if the condition that triggered it is corrected.

The Honda light is pretty neat. At the lowest leve, it flashes briefly when starting the engine. When the service interval is almost up, it flashes a little longer when the engine is started until finally it stays on until reset.

auto · 08-25-2008, 12:14 PM

SERVICE ENGINE SOON 2000 6.8
Definition per ford manual
Your vehicle is equipped with a computer that monitors the engine's emission control system. This is commonly known as the On Board Diagnostic System (OBD II). This OBD II system protects the environment by ensuring that your vehicle continues to meet government emission standards. The OBD II system also assists the service technician in properly servicing your vehicle.

The SERVICE ENGINE SOON indicator light illuminates when the ignition is first turned to the ON position to check the bulb. If it comes on after the engine is started, one of the engine's emission control systems may be malfunctioning. The light may illuminate without a driveability concern being noted. The vehicle will ususally be drivable and will not require towing.

Solid SERVICE ENGINE SOON light

This means that the On Board Diagnostic System (OBD II) has detected a malfunction. Temporary malfunctions may cause your SERVICE ENGINE SOON light to illuminate. Examples are:

The vehicle has run out of fuel. (The engine may misfire or run poorly.)
Poor fuel quality or water in the fuel.
The fuel cap may not have been properly installed and securely tightened.
The temporary malfunctions can be corrected by filling the fuel tank with good quality fuel and/or properly installing and securely tightening the gas cap. After three driving cycles with out these or any other temporary malfunctions present, the SERVICE ENGINE SOON light should turn off. (A driving cycle consists of a cold engine start-up followed by mixed city/highway driving.) No additional vehicle service is required.

Blinking SERVICE ENGINE SOON light

Engine misfire is occurring which could cause damage to your catalytic converter. You should drive in a moderate fashion (avoid heavy acceleration and deceleration) and have your vehicle serviced at the first available opportunity.

No it should not reset by interupting power.
Have it checked with a full function monitor. It may de a manufacture specific code that will not display on a generic monitor. Maintenance light will display service vehicle soon or service soon.

dirko · 08-25-2008, 03:07 PM

Hi Ho: Thanks to all who responded. Auto, thanks for the info from the owners manual. I actually looked in the little booklet, but didn't find anything. It appears that you have something else. Since I bought the MH new I should also have this manual, but don't know exactly what to look for.

I am well over 3 cycles of driving and the light just shines on. I have refuelled three times since I first saw it, having used about 100 gallons of gas.

I will try Auto Zone (sidetracked today), but may have to break down and drive to the unreasonable (in my opinion) Ford truck dealership. They want me to leave the MH for a day just to get the OBD II read.

I'll let you know what comes about from reading the "service engine soon". Thanks again.
Dirk

Wizard · 08-26-2008, 05:24 AM

The last time mine came on, the catylitic converter was bad and had to be replaced.

dirko · 08-27-2008, 06:43 AM

Hi Ho: Well, guess what. The "service engine soon light" went off by itself. What is really ironic is that now (for the first time) the engine surges when idling when it is cold. Went to Auto Zone and sure enough their ODB II tester read: "passed, no codes".

I will dump some injector cleaner in the gas to get rid of possible water, but suspect that either the mass air flow or an Oxygen sensor is going bad.

I sure hate the idea of taking it to the Ford truck dealership. They want it for a day just to read the codes and then will want to do everything except fix the problem.

Thanks again for your inputs, Dirk

dirko · 09-23-2008, 08:16 AM

Hi Ho: OBD II codes are really the answer. It appears that "Service engine soon" is just a way of saying that the failure is not severe. It turned out to be "too lean" in both right and left banks. This can be caused by vacuum leaks or Mass Airflow sensor. Cleaned mass airflow sensor with brake cleaner, reset error code light and all is well at present.

Learned that Auto Zone or cheap OBD II code readers may not work in some cases. It sure pays to have a good mechanic with a professional machine. He didn't even charge me this time.

Thanks again to those that responded.

Dirk