F355 (5.2) Temperature ECU Wiring

Folks, I was trying to figure out the wiring in my F355 (5.2) instrument binnacle recently and found a very dodgy, if not criminal, wiring modification which prevented my Check Engine light and possibly the Slow Down light from illuminating (except when you turn the ignition key to ON, prior to starting the engine). I've had the car for just over two years and I was surprised I hadn't seen at least one of these... Now I know why. Shortly afterwards, I discovered extenders on my catalytic converter O2 sensors, suggesting the original primary cats have been gutted. Now I know why my exhaust was making my eyes water.

I must admit, I didn't fully understand the exhaust system on the F355 prior to purchase.
Anyway, I started to think about getting new cats or getting the old ones recored, but suddenly things got a lot more complicated. I found that there was no plug or wiring harness attached to one of the temperature ECUs on the right side of the engine bay. My local Ferrari guy said that Aussie cars should have three, one for each cat and one for the exhaust bypass. It seems I have wiring for the left cat and and wiring for the exhaust bypass temperature system, but no right hand cat wiring (i.e. from the temperature ECU to the engine ECU). I also have an open circuit between the left cat temperature ECU and the engine ECU.

Would anyone know where the wiring coming from the right cat temperature ECU goes into the harnesses in the engine bay? I have three harnesses going into one in that area, then disappearing above the wheel arch. I'm wondering if I should have four? If I can figure out where the harness has been cut off, I can probably fabricate a new section of harness and splice it back on.

Thanks,
Cheers
Ian.

 

Thanks, 575, but the 355 worshop manual/wiring manual doesn't go into the detail I require (i.e. the routing of individual harnesses). I believe later model car wiring diagrams do this.

Actually, I've already redrawn every wiring diagram in the 2.7 manual to make them a little more user-friendly and I'm currently modifying the diagrams to suit the 5.2.

Cheers

 

The car has had 6 previous owners, Steve. However, the guy before me did a lot of his own work, including engine outs, so surely he must have been aware of this problem. Someone was... I found pen marks on the Engine ECU plug corresponding to the temperature ECUs. He stopped answering my emails... probably because I kept telling him about all the problems I was having with the car... now approaching 30 in total, almost all missed on the PPI.... and now fixed (properly)... but the problems are getting bigger...

Anyway, it looks like someone on the 355/348 Forum has answered my question ... so some progress made

Cheers,
Ian.

 

"Ferrari Maserati Service" at Artarmon.

I eventually figured out what the problem was with the help of FerrariChat.... The wrong harness has been fitted. It never had harness branches for 3 TCU's in the first place. It looks like one of the previous owners had modified a European harness to make the exhaust bypass TCU work (rewired to fit the pins on the ECU). The left cat TCU wiring was open circuit, the other has a strange resistance in it I can't explain (maybe they've added a resistor in an attempt to fool the Engine ECU).

I'm guessing it's an engine out job. Anyway, I've ordered a new one from Eurospares.

Here's a list of some of the problems I found with the car (very few picked up on the PPI)...

Broken recirc flap
Leaking brake/clutch reservoir (car off the road for 3 months while waiting for a new one)
Seat belt warning not working (wires detached and plug missing under driver's seat)
Hazard Button not illuminating during operation (diode burnt out)
Loose earth wire causing rapid flashing of turn indicator lights and other tail lights to flash when the engine warmed up (pulled the car to pieces trying to figure out what was wrong). Also found a cracked light connector during faultfinding.
Console switches plugged into wrong sockets (e.g. rear fog operated the door lock)
Broken stud on oil pressure sender (wire held on with self tapping screw)
Suspension light coming on (found suspension actuator drive wheel superglued together.. ...poorly). Also found another suspension actuator with cracked and reglued internals.
Cracked luggage compartment liners (in about 14 places on one piece alone). One piece was butchered to make an oversized CD changer fit. I think I found the last luggage compartment liners on the planet (judging by the dust on the new ones).
Battery disconnect cover missing
Luggage compartment gas struts not working
Wiring harnesses poorly secured in passenger footwell and console area (all the cloth tapes had become unglued)
And lastly.... a biggie... bits of gear teeth found on the magnetic plug on my first oil change (I'm pretty sure my gear changes aren't that bad).

It's certainly keeping me busy... and poor.... It will never be concourse... but I'm on the right track...

Cheers (and thanks)

 

I hadn't really done much research. It was cheaper than others I'd seen, but I assumed the lower price was because it had 62K on the clock, private seller and the roof canvas would need replacing at some point. The mechanic/engineer at Atarmon knew the owner and even assisted in his home engine-out services. The mechanic was very impressed with his work. The car presented very well on the surface (including the engine bay which was immaculate... at least to my eyes).

Skills honed on owning a Lotus for 16 years After spending $10,000/year on maintaining that in the first few years, I had to invest in some tools and manuals... and thank god for forums!

Cheers
Ian

 

Jeez... too many safety issues on that list. With the Lotus, it was hard to find a mechanic who knew enough about the car without doing more harm than good... even the club-recommended ones. I thought Ferrari would be better, but....

I really wouldn't go as far as saying that. I really don't know how well he knew the owner.. and I can't even be sure that the guy before me knew all that was wrong with his car, but he certainly picked a good time to sell it. If he did know, karma caught up with him... His replacement car's engine blew up after a few weeks of ownership (BMW M5)

In the dim, dark past, yes You could even say the Ferrari was a retirement gift from Qantas. I just wish I still had access to some of their diagnostic equipment... It would have been helpful in faultfinding.

Cheers, and thanks for the moral/technical support

Ian