Slow Down, and Noise

If I have to deal with the temp sensors hopefully their replacement will be straightforward.

https://www.ferrarichat.com/forum/threads/replacing-coolant-temp-sensors.229830/
https://www.ferrarichat.com/forum/threads/104628-temp-sensor.605300/

 

The two blue water temp ones are a breeze, I replaced the the oil pressure sender since I had to remove it while I was in there. Those instructions are exactly correct. It is what I used. The Part #: 104628 I COULD NOT break loose. Next engine out I will pull the manifold and replace that and the one on the opposite side side of the manifold that you can not get to without the manifold off.

#45 & #47
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No I haven't ever used them

 

Technistrada make a cheap thermocouple for these cars.

https://technistrada.com/

 

The thermocouples, no, but quite a few other folks have.

I do have one of their ECUs fitted to my car for evaluation, but I've only had the ECU for a year or so and I haven't done much driving. I may refit the good original if I sell the car (for matching purposes/originality) as they are significantly smaller than OEM.

 

Empty cat would not have "fried" the Thermocouple. My 348 is a non-cat with the Thermocouples inserted into the straight pipes and they are working very well. The Thermocouples will not be damaged even if the exhaust gets red-hot.

As I understand, code 1448 is related to the bypass circuit, not to the left or right Thermocouple circuits. You can bench test a Thermocouple if you take it out, mount it on something that will keep its probe up in the air, connect to it a multimeter that can measure millivolt and heat the prove with a torch up to red-hot. At room temp, you should see ~3-4 mV and the voltage should rise gradually as you heat-up the probe. At red-hot, you will get ~30+ mV.

 

Ratarossa has a video on checking thermocouples:



Lots of "filler". Technistrada is mentioned at around 9:00

 

pretty sure you can swap the cat ecu's and see if the code changes.

 

+1

As Ernest says, you can swap the ECU's. Just be sure to clear the codes and label the plugs and units before you start swapping things over. If you do lose track of what goes where, the wiring diagrams should help. One unit has a violet wire (exhaust bypass) and the other a violet wire (RH cat). The plugs on the ECUs which go to the thermocouples have the same coloured wires, but the wiring is relatively easy to trace.

 

ooops... One unit has a violet/black wire (exhaust bypass) and the other a violet wire (RH cat)

 

Ian, that is good info as the main issue I had when I got my car was they had swapped the cat and bypass ecu plugs during the major!

 

Did you also test the third, bypass, Thermocouple? Code 1448 is related to the bypass circuit so you should look there. Since you are not also getting codes 1445 and 1449 (right and left Thermocouple circuits), they are probably good.

You can bench test the CatECU-s if you connect the Thermocouple, provide 12V supply to the "GND" and "+12V" pins and connect a voltmeter (set to Volts) to "GND" and "Output" pins. At room temperature, it should read ~0.5 volts and, when you heat-up the Thermocouple, up to some 3.7 volts.

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There are separate ECUs on the RHS. They are very close to each other behind the right hand rear wheel. They are mounted at right angles to each other if I remember correctly.

 

Often the errant signals that trip SDL from both SDECU and thermocouples are momentary spike or faults not readily visible on bench testing.

I have three leads tapped into the outputs of my SDECU and have studied this issue in depth invivo. Driving around watching my DVOM. Switching leads. I have videos posted of this real time in here as well.

just because the bench testing shows that a component is good , if you’re still getting a SDL it may be an intermittent fault only visible as I described above. Most thermocouple faults appear like this.

just FYI