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06 BF225 Temp alarm at idle

J

jfish1990

New member
i have a 06 225 honda with 3000+ hours on it, that im guessing was a ex commercial motor then fitted to a pleasure boat.
Engine runs fine with load over 2000+ rpm like its pumping more water through the motor. Just replaced the impeller and gearbox oil and tell tail goes at hundred mile an hour. checked thermostats 6 months ago before transome underwent full revamp. When alarm sounds about 2 mins after idling no engine check light comes on just the temp light on the remote is active. so i will check thermostats to double check them next time but other than that my only other guess is that one of the temp sensors might be going open circuit once temp has increased,

Any ideas???
 
Yes, an O2 sensor can (but not always) cause an alarm. What kind of alarm are you getting - short intermittent, long intermittent, or continuous? If you have a 4-light key switch, what lights are on?

To check for a bad O2 sensor, you need to retrieve the codes from the EPROM in the on-board engine computer - the Electronic Control Module or ECM.

Take off the engine cover and the plastic cover over the electronics on the front of the engine. There you will see a red four-pronged female plug. Use a paper clip to shunt the lime green/white wire to the black wire – that is, the two wires that are closest to the engine when the red service connector is correctly set in it’s holder. If in doubt, invest in a SCS service connector, which you can order online. Part number 070PZ-ZY30100.

Once connected, turn on the key switch and observe the number of blinks on the check engine (MIL) light. If the MIL comes on and stays on without blinking, you have one of the following conditions:
• Short circuit in the service check connector wire
• Short circuit in the MIL wire
• Short circuit in the sensor system power supply
• Open circuit in the power supply line to the ECM
• Faulty ECM

If the MIL comes on, then goes off after a few seconds, there are no codes in the EPROM.

If the MIL starts blinking, then count the blinks, which will indicate the fault code. You may get long blinks and short blinks. For example, two long blinks,followed by five short blinks, would be a fault code 25.The blink sequence will repeat itself until you turn the key off. If there is more than one fault, you will get multiple fault codes. For example, three short blinks, followed by two long blinks and five shortblinks would be fault codes 3 and 25. Post the number of blinks and I will try to tell you what the error code is. Or, send me an e-mail at [email protected]and I will send you the codes.

If you get only one blink, that repeats about every three seconds, or so, that is a faulty O2 sensor. If a faulty O2 sensor is indicated, first check the wiring and connector. A loose or corroded connection can set off that alarm.

 
Chawk, it's only after say 2mins at idle it does a constant alarm. I've got the engine check light and a charge light on one panel but not light and on the throttle I've got oil and temp. (sorry just tryn to make a clear picture for you), which the temp light is on. I'll check O2 sensor tomorrow and blink codes also and let you know as soon as I know,

Cheers

John
 
I'm still not clear what lights are on with the continuous alarm. See if this table helps...

BF 225 Alarms
Buzzer
Lights
Condition
Oil Pressure
Overheat
MIL
Alternator
(Green)
(Red)
(Red)
(Red)
None
ON
OFF
OFF
OFF
Normal
Continuous
OFF
OFF
OFF
OFF
Low Oil Pressure
Continuous
ON
ON
OFF
OFF
Overheat
Continuous
OFF
ON
OFF
OFF
Low oil pressure & overheat
Continuous
OFF
OFF (2)
ON
OFF
Low oil pressure & abnormal PGM-FI
Continuous
OFF
OFF
OFF
ON
Low oil pressure & abnormal alternator
Continuous
OFF
OFF
OFF
OFF
Low oil pressure & water in separator filter
Continuous
ON (1)
ON
ON
OFF
Overheat & abnormal PGM-FI
Continuous
ON
ON
OFF
ON
Overheat & abnormal alternator
Continuous
ON
ON
OFF
OFF
Overheat & water in separator filter
 
Fourth one down, oil pressure and overheat, can't remember if oil light was green or not, if I remember rightly it was just the temp light, will throw motor in the water next weekend and try again after checking thermostats
 
Okay - understand that the green oil light is OFF and the red overheat light is ON. To make sure all your lights are working, when you first activate the key switch, all four lights should come on briefly, then two beeps from the warning buzzer, then lights off, except the red alternator light should stay on until you start the engine. Depending on how that green oil pressure light is situated, it is often difficult to determine whether it is on or not, so check it closely.

The t-stats seldom stick in the closed position. When they stick, it is usually in the open position. But you may have one of the rare cases where they stick closed. An overheated engine will thin the oil and may indicate low oil pressure.

So, yes, check those t-stats as your first course of action. If that doesn't pan out then check the wiring and connection to the each of the overheat sensors - you have two of them. If you have access to a heat gun, it might be a good idea to check each of the heads and manifolds to make sure you really are overheating.

Otherwise, shunt the service connector as described earlier and check what codes you have.
 
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