232 Exhaust Temp Sensors

[Beachbummer]

Yes 2008 California emissions on the label! I don't think it had a cat, but certainly different. Thanks!!!

 

[buckbuck]

Your exhaust is very different than mine and we have the same year / same engine. I recall people pulling the cats back then. Do you have a service manual?

 

[Beachbummer]

I do have one, but as I look at the different part break outs, I can't easily ID my set up. Maybe cat was removed 2 owners ago? I'm about to cover the boat and heads out, I'll try to figure out what the heck I've got.

It ran well today and exhaust looked good and paths were clear, so I'm calling it good for now. Exhaust not cool to the touch, but both engines had same temp by hand feel. Forgot the infrared thermometer at home.

EDIT: So, I have most likely 2008 Yamaha SX230 HO CA & NY (SXT1100CLG) Exhaust 1 | Babbitts Online I don't see a Catalytic converter anywhere, so not certain of the reason for the cooling variation.

Model SXT1100CLG

It seems there are 2 exhaust temperature sensors 2008 Yamaha SX230 HO CA & NY (SXT1100CLG) Electrical 2 | Babbitts Online

Number 18 and Number 19 here. both rudely expensive.

It also seems there is indeed CAT within the exhaust. Had no idea.

Today was good, will keep and eye and confirm tomorrow. From what I can see everything appears to be working and flowing as expected.

 

[Beachbummer]

Can you take a picture of your exhaust when you have a chance??? Thanks!

 

[buckbuck]

I hope these help. On my manual the first couple pages show a diagram of cooling flow on the CA engine exhaust.

 

[Beachbummer]

Yes, thanks! Mine is a bit different, and I found the full manual. For sure mine is a CA engine and the water flow path is a little different.

If your loosen the 4 band clamps the small exhaust section that says "Up" on it comes off, and then you can inspect the condition of the exhaust/water mixing holes without taking the engine out. In my case this was only a learning exercise because as you saw, there are no holes there.

It is a pain to get off and on as you have to force the piece thorough the rubber a bit, but it does come off.

Thanks again.

 

[Beachbummer]

I have reviewed the manual for our boat that includes the information on my engine, and I have not been able to determine what exactly triggers a 53.

From the manual....
Exhaust temperature warning control
The following warnings are activated according to information received from the exhaust temperature
sensor.
• The exhaust temperature warning indicator flashes .
• The "WARNING" indicator light flashes.
• The buzzer sounds. (The buzzer can be deactivated by pushing any button.)
If these warning remain on, the engine is not stopped.
If a malfunctioning exhaust temperature sensor is detected, the above-mentioned warnings are activated
and diagnostic code 53 is displayed on the multifunction meter.
When the exhaust temperature is 300 °C (572 °F) or below, 300 °C (572 °F) is displayed on the
"Engine monitor'' of the YDIS.
If the exhaust temperature exceeds 300 °C (572 °F}, the exhaust temperature measured by the
exhaust temperature sensor is displayed.
--

It seems the signal triggering a 53 is different from the "Exhaust is too hot" signal.

 

[buckbuck]

Hmmm...so where do you go from here?

 

[WREKS]

How Hot Does a Catalytic Converter Get – AutoVfix.com seems to indicate that leaded (non-ethanol) gas may not be good for catalytic converter.

 

[PaulyB]

@Beachbummer have you resolved your issue yet? Are you still getting the exhaust temp overheat? I just started getting one on one of my engines recently. I have done everything except for change the catalytic converter to try to fix the issue with no positive results. I am considering swapping the cats between motors to see if the code goes to the other engine, but dont know when I will get to it yet.

If I run under 8700 RPMS i dont get the error code, but if I run over 8700 rpms for over a minute the code will come on.

 

[Beachbummer]

What is the exact code you are receiving? I got this error code once more and not again. And I go out every weekend, the Mahal says it's the sensor but at $300+ I'm not eager to replace it.

The exact code is important because it might be an overheat, but it could also be the sensor error.

There are 4 small holes under the black 90degree cover that you can also clean and unclog if it's an exhaust overheat. It's a pain to reach them by only removing the large house clamps keeping it in place, but it can be done. I would suggest you check good flow on the easier to remove hoses closer to where the exhaust water mixes in with the exhaust flow, then check these holes.

 

[PaulyB]

I’m getting a code 53 exhaust temp overheat. I swapped the sensors from starboard to port hoping the sensor was bad, but the same engine threw the code again. I’ve pulled the cat out and looked at it, it didn’t look bad, but who knows. I count some cataclean tonight, I’m gonna try that tomorrow.

 

[Beachbummer]

I don't think 53 is an overheat code
If a malfunctioning exhaust temperature sensor is detected, the above-mentioned warnings are activated
and diagnostic code 53 is displayed on the multifunction meter.

I think it might indicates a short in the wiring or the sensor. Since the failure stayed on the engine when you moved the sensor, I would check the wiring making sure it's well insulated all the way back to the ECU. If the wiring wore though the insulation and is rubbing and touching the engine it could be grounding the signal, causing your problem.

Wild idea.

The sensor measures very high exhaust temperatures, If it was overheating you could probably tell by touching the exhausts that this one is MUCH hotter than the other. (still possible?)

Best of luck!


-The manual also indicates on an overheat the buzzer comes on, while that's not the case for the malfunction. Manual Info below:


Exhaust temperature warning control
The following warnings are activated according to information received from the exhaust temperature
sensor.
• The exhaust temperature warning indicator flashes .
• The "WARNING" indicator light flashes.
• The buzzer sounds. (The buzzer can be deactivated by pushing any button.)
If these warning remain on, the engine is not stopped.
If a malfunctioning exhaust temperature sensor is detected, the above-mentioned warnings are activated
and diagnostic code 53 is displayed on the multifunction meter.
When the exhaust temperature is 300 °C (572 °F) or below, 300 °C (572 °F) is displayed on the
"Engine monitor'' of the YDIS.
If the exhaust temperature exceeds 300 °C (572 °F}, the exhaust temperature measured by the
exhaust temperature sensor is displayed.



-



EXHAUST TEMPERATURE SENSOR
(6AA ENGINE)
1. Measure:
• Exhaust temperature sensor resistance
(at the specified temperatures)
Out of specification ➔ Replace the
exhaust temperature sensor.
Measurement steps:
• Heat the exhaust temperature sensor
using an electric furnace or similar heating
device.
• Measure the resistance when the specified
temperatures are reached.
~ Exhaust temperature sensor
resistance (reference data):
White (W) - Black (B)
300 °C (572 °F): 73-241 kOhms
600 °C (1 ,112 °F): 0.86-1 .58 kOhms
900 °c (1,652 °F): 64-90 Ohms

 

[PaulyB]

Touching the exhausts wont do much I dont think, because water is flowing throught the outside of the exhaust manifold keeping them cooler to touch. The exhaust gas is what the code is throwing saying the exhaust gas temperature is high, not the engine temperature. It only happens when the motor is run hard for a minute or more. If I run the boat under 8700 RPMS I can run it all day without it throwing the code. When I go over 8700 RPMS for over a minute, the code appears. I have the 6AB motor with the catalytic converters. Apparently these cats are only supposed to last about 10 years, so they are probably dirty and causing the exhaust temp to be higher than normal. I am going to try cleaning them with a cat cleaner that you put in the fuel. If that doesnt work I am going to swap cats from one motor to the other and see if its the cat or not.

 

[Beachbummer]

But, are you getting a buzzard alarm, or light only? Read the manual sections above carefully. Overheat is not the same as sensor/wiring signal problems.

 

[PaulyB]

I never have received a buzzer sound. I dont believe my boat does it. Even if I suck something up in the jet drive and the engine overheats, to where it kills the motor, I dont get a buzzer. I dont even know what "button" i would push to silence it even if I did get it. I believe that language is probably more for jet skis and not the jet boats. Have you ever heard a buzzer?

 

[Beachbummer]

I have had the buzzer cone on on an engine temp overheat due to weeds in the intake tunnel.

I'm certain 53 is not an overheat, but a complaint that the signal arriving at the ecu is not within the normal sensor range of reporting temperature.

For whatever is worth, my old boat had a thermo-switch and due to some poor wire routing the insulation rubbed off and touched metal, shorting the sensor wiring and causing a "false" overheat signal. If that was to happen on your boat for this sensor, I expect you would get a 53 code, as 0 Ohms is not in the expected range the ECU expects from the sensor.

 

[buckbuck]

@Beachbummer Do you have cats on your engines? I have a 2008 and do not get a buzzer on an overtemp but my boat does not have cats.

 

[Beachbummer]

I did have CATs, but not anymore. We just completed the replacement. My exhaust was quite a bit rusted and allowed water to return to the cats and rusted through a few places it would seem. The sensors have been "adjusted" but I hope this thread serves to warn of checking exhaust and exhaust manifold health when suspect things start happening in this area. Maybe it saves someone else. By the time I caught it there was already a lot of rust in my California exhaust.