2000 360 O2 sensors heater circuit

Both banks?

The L/R bank heater circuits have nothing in common. The fuses are powered by their respective Motronic Master relays. If a relay failed for a particular bank, however, the banks wouldn't work. If it's a single bank, it may be a wiring issue downstream of the fuse.

Did you check power on the fuse or just inspect it visually?

 

The fuse powers the heat for both sensors (splice involved). Power goes into the forward sensor on pin 3 of the precat sensor and pin 1 of the postcat sensor (12 volts).


My diagrams are not for the faint of heart. If you can give me more information, I can point you in the right direction on the diagrams.


Basically, control for the heat comes from the ECU (one wire for the precat, one wire for the post-cat). e.g.

Pin 50 on the inboard connector of the RH Motronic ECU (assuming you have a Coupe and not a Spider) is attached to pin 4 of the precat/upstream sensor and controls the application of heat. Brown/white wire.
Pin 34 on the inboard connector of the RH Motronic ECU is attached to pin 2 of the post-cat/downstream sensor and controls the application of heat. Brown/black wire.

The 12 volt power wire on the RH bank precat and postcat sensors is violet.

 

P.S. Sorry, lots of edits in my last message.

 

A power reading is more reliable. At least that way I know the wire between the relay and the fuse is ok.

If you check for voltage at the sensor connector, that can be done with just the key on. If you have voltage there, then it's either:

1) an O2 sensor issue
2) an ECU to sensor wiring issue
3) an ECU issue

So the RH ECU plug will be the lower one. It will be the upper plug on the LH ECU.

Did you isolate the issue to a specific bank?

 

No specific relays, just the L/R Master Motronic relays. Do both banks run?


Plug pinout... Numbers are left to right, top to bottom, with the face of the harness connector in this orientation.
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Maybe someone can chime in here... Are there any special requirements other than getting the engine warm for smog tests? Thanks!

 

What part #'s for your 4 sensors? I presume you know there's a difference between the upstream and downstream ones.

Doesn't hurt to check the resistance levels on the sensors (for the heater circuit) - typically the two same color wires are the heater circuit.

Did you try resetting the ECU already?

The issue you're trying to resolve currently is the car not going into I/M readiness mode or something else?

Ray

 

What scanner do you have over there?

Sometimes that stuff can take a while to settle down. We just replaced the O2 sensors on my neighbor's 4Runner and it took forever to get into ready state. Even when doing the drive cycle cheat sheet stuff, sometimes the only answer is just drive for a few weeks.

Ray

 

Let me know what you think of the Autel. Which Autel did you go with? I just upgraded mine from a $20 Amazon one to the XTOOL A30M (as outlined here in this thread):

https://www.ferrarichat.com/forum/threads/obd2-bluetooth-adapter-question-obdlink-mx-vs-xtool-a30m.707168/

I'm gonna scan my neighbor's 360 soon using it (the same neighbor w/ the 4Runner mentioned above there).

From the information on the thread above, I gather the XTOOL doesn't have as much support for Ferrari as the Autel's do; would be curious to hear your experiences over there when your Autel arrives.

Ray

 

Yea XTOOL doesn't appear to have updated their Ferrari module lately.

The 360 my friend has is a 2002 I believe. Not holding my breath.

Ray

 

As mentioned before in many threads you cannot beat for a reader onlly ..this

https://a.co/d/imUOIuO

 

Yeah that's what I saw as well. I wrote XTOOL and asked them about it and if they had any plans to update the Ferrari support.... crickets.

Ray

 

Flash32 in da house!



Ray

 

I was just searching around the Autel website.. it's interesting that the AP200 shows plenty of Ferrari support (and there are slight variations of the AP200 - e.g. AP200C, AP200H, AP200M) while the later version (the AP2500) seems to lack it.

Ray

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