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2005 BF 150 SCS codes

H

hornblower

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My Bf 150 is running poorly at idle. I've replaced all filters, new plugs, thermostats, MAP sensors, IAC valve. Actually swapped the MAP and IAC from my other BF 150 and that didn't fix the issue. I have the SCS connector and I'm getting the following codes. 7 short blinks then pause long blink then pause 4 long blinks then 1 short. I have the shop manual but can't determine what problem the codes reflect. Any and all help is really appreciated.

Greg​
 
That is a 7 code and 41 code. If the 150 has the same codes as the 200/225, the 7 code is faulty, shorted, or disconnected TP sensor and the 41 code is faulty, shorted, or disconnected HO@ sensor, OR a sparkplug misfire. Those codes are hard to find in the shop manual. So, when I finally found them, I made a copy and put them on my computer.
 
Thanks for the reply. Code 7 is the TP sensor and 41 is the AF sensor according to my shop manual. Looks like I'd have to replace the entire throttle body if the sensor is bad!
 
Hopefully HondaDude will kick in and let you know if that is the case. I've never had any trouble with mine. Check the wiring and connections first.
 
Erase the codes and recheck before getting too concerned over what to replace. If you disconnected any of those connectors with the key switch on, it would have thrown a code.

Then run the engine and recheck.

Mike
 
Performed a compression test today according to the shop manual. All for cylinders read just under 150psi. This is concerning. Swapped throttle body and most all the sensors and never got the engine idling smooth. Engine good for about 60 seconds then starts shaking and sound like it is missing on more than one cylinder. Also swapped computers. At the end of the day I unplugged the AF sensor and it seemed to run better, and this sensor came off the good engine???? I'm lost on what to try next. Not sure how to erase codes...is the kill switch the same thing as what the manual refers to as the emergency stop switch?

Thanks for any and all advice.
 
Yes, the kill switch is the emergency stop switch.

If you have a stop switch that you can push in while the safety landyard is connected, with the shorting plug attached, turn the key switch to on and within 20 seconds...push the stop switch in 5 times slowly. On the last push, you should hear a couple of beeps indicating the codes are cleared. If you have the stop switch that you can not push in with the landyard attached, you will have to remove the landyard and hold the button out with your fingers....turn the key switch to on....then release the button 5 times within 20 seconds. I think you get the idea.

As you probably know, the compression should be at least 200. You are advancing your throttle all the way when you do it, aren't you?

If you are, then the next thing to do is a leak down test to see where your leaks are.

If the valves are out of adjustment or if you have a carboned up engine, that will affect your compression and idle. See this thread....http://www.marineengine.com/boat-forum/showthread.php?407487-2006-Honda-BF135-Rough-Idle

I go over a problem I recently had and how I fixed it. It may or may not work for you.

You have to do the leak down to see where to go next....otherwise, you are just guessing.

Mike
 
I decarbed the engine today. Seafoam and 3/4 gallons of gas in a pony tank. Ran the engine 15 minutes and let sit for 15. Cranked her up and no smoke. Ran another 15 minutes on the pony and let sit for 30 and still no smoke. Wondering if I performed the decarb correctly....maybe no carbon build up???? Didn't get to perform the leak down, gotta get the equipment. Did notice again that the engine idles considerably better with the AF sensor unplugged. Cleared the SCS codes and now get a constant red light.
 
The constant light indicates that there are no codes.

When you used the seafoam, did you drain the vapor separator before you started? If not you had several minutes of run time on the plain fuel.
The engine should be run under a load and should be up to operating temperature.

Try a couple of more times and then check compression again to see if there is any improvement.

It is possible for the A/F sensor to be working but not working correctly and not throw a code. Removing it would cause the ECM to fall back to default settings.

You said you swapped all of the sensors. Did you swap the A/F sensor?

Mike
 
Ordered a used AF sensor off Ebay. Installed and the engine idles much better but I'm getting an alarm for the AF sensor. 4 long flashes and 1 short Is there an ECM reset? Maybe the used sensor is also bad. Installed it in my other engine and it does the same.

Greg
 
Worked on the engine today. New (used) AF sensor continues to trigger alarm. I can install the original AF sensor and it idles very bad but does not trigger the alarm or display any codes. Put the new sensor in and it idles great but triggers the alarm about a minute after cranking and displays the 4 long and 1 short lights. I notices the AF sensors the came on the engine are Denso 192400-1152 and the sensor I got off Ebay only has the OHS:::596-H1 and came off a 2007 model. Wondering if this is not the correct sensor for my engine.
 
Are you clearing the codes on the ECM EPROM before installing the new sensor? If so, then I suspect that the new sensor has differnet specs than your old one, and the ECM doesn't like that. But that is only a guess.
 
I can not comment on the markings on the sensor. I did check the part number....and it has not changed since the 150 was introduced. That doesn't mean that they did not change manufacturers.

If the sensor from the other motor worked correctly, then the sensor you got from ebay is not correct or is out of range.

Mike
 
Received another AF sensor, Denso model. Installed it and it the engine idles bad with nor alarm or codes. Engine runs good for about a minute then start a cycling of sputtering then smooths out then sputters and so on. Not sure what to try next, heard there was a recall of the ECU of some BF 150. However I swapped the ECU from the other engine with the same results. Confusing that one of the AF sensors I received makes the engine idle fine but I get a alarm with a code a four long blinks and one short. Tempted to buy a brand new AF sensor but it's kind of a shot in the dark.
 
After looking over my shop manual I noticed the code 41 refers to the AF sensor heater (current) and code 48 refers to the AF sensor (voltage too low or high). Would replacing the sensor address all the possibilities of the 41 code? Could my problem be the AF sensor relay? Where is the AF sensor heater?

Greg
 
The heater is in the AF sensor. The heater relay is located in the case that holds the ECU.

If you said the trouble followed the AF sensor to the other motor, then it is the sensor.

Unless I missed it, did you say that the AF sensor from the good motor still made the engine run bad?

Mike
 
Yes, the most recent AF sensor I received made the engine run just like the original AF sensor, bad. I've received two sensors, the first made the engine run much better but triggered the audible alarm and code 41. The second sensor didn't trigger the alarm or code but made the engine run bad.
 
I don't think I asked the question correctly....

Did you take the alleged faulty sensors and install them in your other motor? If so, how did the other motor run?

Mike
 
If you put the sensor on the good engine and it runs ok, then you know it is good.

If you are still getting the alarm, then I would check the heater relay circuit. Could just be the #3 fuse is blown.

Mike
 
Mike, I'd like to send you a short video of my engine idling in hopes it might better help determine my problem. What would be the best way to get it to you?

Just checked fuses all are ok and swapped heater relay with no changes.

Greg
 
Sensor worked fine on the good engine. Swapped the injectors today just to see if would fix my problem but no change. Removed the muffler case and held a rag soaked in gas in the throttle body and the engine ran smooth, pull the rag away and it would run rough again...not sure if or what this could be indicative of.

Greg
 
It looks like you can insert a short video in your post. It is the second icon from the right on the top of the reply box.

As far as trouble shooting for the 41 code....p 5-40 (in my manual), in the PGMFi section....goes through a step by step as to what to check. I suggest following those steps to check the wire continuity, etc.

On another note....if the engine runs better with a rag in the intake, the rag runs it richer than it was when it was running bad.

As I read back over all the posts, you have already switched the IAC's, which I would have thought could be a problem....
You checked compression and did some decarbing. Did you recheck compression...with the throttle only at full throttle?

Did it improve?

Mike
 
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