360 Intermittent Key-On w/ Blank Dash

This weekend I stated experiencing a weird phenomenon with my dash. On occasion, When I go to drive the car, I'll push fob button to unlock/mobilize the car, then put the key to the run position before starting, and I get a blank dash. I do not get the "check ok" or shift position, and instead of all being illuminated like usual, I only get the "air bag" warning light. If I cycle the key off and back on a few times... no change. Backlighting still works however. If I push the FOB button to lock and activate the mobilizer, then push it again to unlock/re-mobilize, then go back to key on, everything works again as it should.

With the blank dash the car will still start, but just no indications or needle movement. I can hear that It will also shift into 1 or R (F1) but then go right back into N.

I don't know enough about the immobilizer architecture but it certainly seems to be correlated to the dash issue. Anyone ever run into this?

 

Thanks Ian, Usually if I go to key on without deactivating the immobilizer everything lights up normally (ALL warning lights for about a second then extinguishes to only shows what's active like sport, brake and seat belt) and it will even let me crank the engine, but it just won't fire until disarmed/mobilized with the FOB.

Here is a video of it happening. You can see the immobilizer is deactivated, I go to key on and only get the airbag light temporarily, nothing else. I then arm/immobilize it temporarily, then deactivate/disarm and go to key on and everything lights up fine. It actually took me multiple tries this time around before it worked again, maybe 6 or so. Previously It would do it right after that sequence on the first try.



After taking the video I saw your comment and didn't even think about plugging in the scanner for some reason, and I did in fact have a P1675 "Instrument panel : CAN Line Timeout (B2)" which I cleared, but havent had a chance to see if it returns. I'm assuming it will since I didn't actually fix anything.

I could only find very limited threads about that particular code, but seems to be power/ground related, not necessary the bus itself. https://www.ferrarichat.com/forum/threads/360-can-interface-line.522156/

Another important note that I'm realizing now might be related, about the same time this started happening, I had a problem with my hazard light switch on the center console. I had pushed it and it wouldn't turn back off. Rather than driving home with the hazards flashing I popped out the cupholder and disconnected the connector behind the switch and drove it home. I wonder if that was what triggered the fault code. I can't remember if this was before or after the dash issue though. I later pulled the console to get the switch out to disassemble and clean the (what seemed to be) sticky soda residue from the contacts and the switch operated normally again. Yet the instrument cluster issue was still happening. I also noticed a chaffed wire with some bare conductor right at the transmission control panel connector, which I repaired. I can't recall which wire this was through but it did not fix anything. I can't help but get the feeling the issue is somehow related to the hazard light switch, or wiring around it. I guess I'll pull the console back out and thoroughly inspect all the wires and connections.

 

Strange indeed, So after I deleted the trouble code, the problem has not returned (knock on wood), where before it was quite consistent. Doing a little research, it looks like turn signal and park light status is reported on the CAN bus, so maybe powering on and driving the car with that button connector disconnected triggered the fault code, and possibly the park light button as well, I don't remember If I reconnected that one or not after I unplugged it for access to the flasher. Also with the immobilizer/alarm tied to the park lights, turning that on and off and flashing those lights may have had something to do with it? This is all speculation at this point.

Is it common on these cars for stored codes to actually alter the behavior even though the (likely) triggering condition was corrected? I'm not used to deleting codes and having it actually fix a problem.

 

Just kidding... Went to run an errand and it happened again both times I went to start it, same lone P1675 DTC. When I get the chance I'll be checking the data bus for 60 Ohms and taking a look at the center console wiring, since that was the only thing that's been messed with since it started happening.

 

I can't recall but after looking at the pinout of the cluster ( https://www.ferrarichat.com/forum/threads/f360-cluster-diagram-pinout.683788/ ) , I may just have misinterpreted someone speaking about the unit getting a digital input of the park light status.

I'm also going to check out my grounds. It would make sense that this could be caused by a poor ground as another has reported on the first link I posted. And granted the airbag light still illuminates, for all I know that could be grounded through the airbag ECU, so it's not really relevant. I'll give special attention to the grounds in the console area since I was in there.

Might be a few days, but I'll be reporting back.

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