Good Afternoon Gents, We have a 550 in our shop that has an actual functioning gear indicator in the Instrument Panel (yes, its a 3 pedal car). Ive not seen this before and assume its some sort of aftermarket add on. The car has a few issues and I'm trying to eliminate what ever aftermarket system is creating this function but I cannot find anything inside the car. Its obviously done with some sort of computer/math channel calculation using speed and rpm, as it only works with the car in motion and there is no sort of gear position sensor. I thought I found who made it on a late night google session but now I cannot find any traces of it at all. Have any of you seen or heard of this function or who makes it or how it was done?
Thread subscribed. I’ll look forward to hearing more about this…not sure I’ve seen or read of a 550 having that option.
I use a standalone ECU on another car which uses the speed signal and a gear ratio table to deduce in function of engine speed in which gear the car is driving. I would guess that similar witchery was applied here, and I would suggest you to have look at the ABS control unit to see if the speed signal was somehow hacked, possibly through the harness plug. It seems really bizarre that a previous owner could have had this installed when all it takes to know which gear is engaged is a glance at the shifter...
Late 550s had some F1 functions incorporated before the decision was made to wait for the 575M for F1. Is it possible the gear indicator is part of that? Note the gear indicator does not work on 3 pedal 575Ms, though, but the 575M DME is completely different. Where is the gear indicator on the instrument panel?
Terry I asked for pic for the that reason ..but I assume in the check ok box ..but then again it could be that little box above it Sent from my moto g power using Tapatalk
I was assuming it was similar to the 456M GTA in the middle of the cluster as alluded to but curious to see in action.
Eric, on your car what is now the cruise control light is where the F1 warning light is on late 550's were. There are several unused circuits in the fuse panel dedicated to the F1 system. There were no external wires connected to it though. (I left those circuits out when I made the new fuse panel which I assume you are still using)
And that kind of comment and knowledge is what makes you and the other tenured professors of the subforum amazing. Thx Oh and yes, no change to the fuse panel.
Yes but the 550 cluster and the 456M cluster are functionally nearly identical (there are several minor differences, most obvious of course being the type font/dial design). This is why I assumed they used the same digital display as the MGTA for the gear selection (my assumption, see below but welcome photos of the actual implementation!) 550: Image Unavailable, Please Login 456M: Image Unavailable, Please Login
Attached is a photo of the instrument cluster and a video. The function of the gear indicator is obviously setup via a math channel based on speed and rpm. As you can see it momentarily displays the wrong gear when the rpm drops until it's firmly in the next gear. I can't find anything in the car so it must be modified internal to the instrument cluster. My question to you guys was if anyone here knew of such an aftermarket device. But since I'm just getting more questions, I'm going to assume no one here has seen this before. Image Unavailable, Please Login
Ah my suspicion was correct. If no other wires going into/out of the cluster then yes likely internal to the cluster, likely the display box vs a piggy back on said display. In other words, they may have swapped / customized a 456 display (PN 180226) or hacked up a 550 warning display; in which case swapping back to the 550 part will 'correct' it (ie 179152).
I assume you check under stick shift itself for any electronics ..it does seem to go by where the stick is not any gear ratio etc Does the gear shift indicator work when parked with just key in on position ..not started ..if so ..I would really look under shift plate etc Sent from my moto g power using Tapatalk
Chris- Nobody suggested you had a 575M instrument panel. They are quite different, as we all know, and incompatible with each other.
As @Auraraptor suggested, the display may be standard. The 456M WSM pinout for the display shows a few pins labelled "transmission xxx". The wiring from the Digitek display to the first connectors on the dash may also be standard on the 456MGTA and the 550. The modified car may have tapped into plugs 10F, 11F and 8F under the dash. Image Unavailable, Please Login On the 456MGTA, some of the wires coming from these three plugs would be hooked up to one (or more) of the Automatic Transmission ECUs. Unfortunately, there are a few unknowns in the OEM wiring diagrams and my GTA automatic gearbox diagrams are incomplete. Here is the pinout for the Digitek display on the 456M: Image Unavailable, Please Login The wiring between the Digitek display and the first plugs is shown in this diagram: https://www.dropbox.com/t/p2aWeQKXXQzS0DoS
This is quite cool. Have never seen this before. One question to all of us. Are there any warning lights in this display from factory? I can not remember having ssen any lights in this small screen...
Hmmm... going by part numbers, the displays are not interchangeable between the 456MGTA and 550. Here's the 550 pinout from the WSM. Image Unavailable, Please Login Oddly, pin 9 on connector C is blank. That's the seatbelt indicator.
I would like to know as well and which pins control that .. unless not pin drive but internal ecu calculation
Gotta be based on something like this: https://ecumasterusa.com/products/ecumaster-digital-gear-indicator?variant=31302713933961
It seems like the 550 has the facility to illuminate at least one of the auto gearbox warnings lights. In the following schematic, the red box shows where a warning light could appear (with an earth put on one of the pins of one of the 20 pin plug going to the instrument panel (8F)). Image Unavailable, Please Login The VB wire is power. Here's the light as it appears on the 456MGTA (and also the warning which appears on the digital display). Image Unavailable, Please Login I don't know if the signal going to the digital display warning light is analog or digital.
