Tach and Speedometer do not work on my automatic 93 RX7. HOLD light flashes
 

Does anyone has an idea why my tachometer and speedometer do not work?
I also noticed that the HOLD light flashes after I start moving the car. My overdrive also stopped working. I sent the gauge cluster to a company in MA called BBA Reman, and the tested all the gauges and said they work. I also took the car to the local Mazda dealer and they contacted someone in CA and they said those cars suffer from that particular issue. I tried replacing the tranny computer but to no avail. Any help will be greatly appreciated. Thanks

Dragging this back out of the archives....Having an identical problem. Any others experienced this?

Actually, my overdrive does work...but the tach is sitting at 800rpms, the speedo at 10 or so, and the hold light flashes...any ideas?

Wow... I have an auto and I dont have any of these problems yet. keep us posted on how this turnes out.

Jeff

Bump

The response is overwhelming....bump again.

anyone ever figure this out????

i had the exact same problem on my auto when i had a local transmission shop rebuild mine after it went out. The tech did not take notice to where the wiring harness' went. I finally found a guy in Portland that fixed my car in 5 minutes after i had it all over my local town to half dozen transmission shops. THe guy in portland said the mechanic had left a wiring harness lying loose cuz he couldnt figure out where it went. I would look on top of your bell housing and see if you see any wires or harnesses floating around.... all i know is my car did the exact same shit and he plugged a wire back together from the transmission and it worked great

I also have a 3rd gen with auto trans and 4.33 axle ratio. Where did you find the speedometer gear to match the 4.33?

this thread is one of those that starts and never climaxes. it lets lifted up only to slump back down...

I have the same issues. Anyone else find solution other than loose wires?

Thanks

Its a service TSB recall, or it sounds suspiciously like one of the factory recalls for the 1992 - 1993. Google "FD3S Hold light flashes" and near the top of google results should take you to the recall information.
From memory, it involves replacing the primary engine ECU with an N3A1-xxxxx-B revision ECU. Not the trans ECU.

thanks SA3R, I'll check it out. Having this be a recall fix would be amazing.

I doubt any Mazda dealer would fix it if it is covered under a recall, as the cars are so old now...

But it is easy to fix yourself.

Here is the recal info for you:

Service bulletin #012/92, Category K, issued 7/15/92

Applies to 1993 RX-7 built prior to May 11, 1992

If the hold light starts flashing while the vehicle is running, and torque reduction control fail code is 57, replace engine ECU under warranty.

New part# N3A2 18 9E1B
Old part# N3A2 18 9E1

So you would need to verify that this is in fact your fault, and the to rectify it, purchase the "B" revised ECU on Ebay or something, and plug it in, and hopefully it will solve the issue..

The Hold Light will flash when there is something with the transmission. Similar to the check engine light, you can set it up to read the code that the trans is throwing.

I've noticed that when the speedometer is not functioning, the hold light will continue to blink until the speedometer is working again. This is likely because the transmission computer is not getting vital information that it needs to properly shift the car i.e. transmission output rotation speed (converted to car speed through the speedometer gauge). IIRC, the car goes into a limp mode of sorts and just does it's best to guess the car speed from it's other sensors and shifts a bit conservatively. I think it also locks out the Hold mode as well so you can't even shift it yourself.

Now, the hard part is why is your speedometer not functioning. There are many things that can go wrong; the speedo itself could be bad, it could be a bad electrical connection between it and the speed sensor, or it could be a bad speed sensor, or a bad ground somewhere. Seeing as your tach is not working as well, I'd guess at a bad gauge cluster since that is all too common with these cars. Swap it with a known good one and see if your problems go away. Short of that, I'd get out the service manual and check every electrical connection and sensor for proper operation.

Hold light often starts flashing, Also, occasional code 6 speed sensor code gets thrown on check engine light.
Mechanic's book says 4 hours labor to replace the speed sensor, but does not have information on what disassembly and reassembly is required to access the port and the electrical plug.
Any advice, experience, recommendations?

93 FD3 automatic transmission

The problem continues... Another posting says it is the tranny computer not the engine computer, unless it is mistaken.
Three phases to my tale:
1. speedometer always works fine, but odometer stopped displaying for a year, until I did an engine overhaul, then the odometer started working fine for a couple months.
2. Got flashing hold light and check engine light code 6 and odometer not showing milage and trip odometer resetting to zero on every key off key on. Did a replacement of the tranny input speed sensor because of the code 6. Upon reassembly and startup, everything worked except the trip odometer would still reset to zero every restart. That lasted one day, then all symptoms recurred.
3. Replaced the computer mentioned above (which was an A model) with the B model. Upon reassembly and startup, everything worked (did not verify trip odometer ). Next day all symptoms recurred (have not verify trip odometer).
My underlying question is why does it work for one day and then quit again. Seems this might provide a clue to the cause.
And the trip odometer resetting is odd too.
I would like to get back the HOLD function, and get rid of the check engine light. I hate to ignore it even if it likely is not critical. Seems it might also be difficult to sell with that behavior.

The odometer issue is most likely a problem with the instrument cluster, this is a very common problem. There have been a great deal of work trying to track down the components on the odometer/speedometer board and how to repair them, it's a tricky process. It's not uncommon for it to not work, then you disconnect the battery or the postive terminal and suddenly it works for a while.

I'm not sure if that would have any relationship to the hold feature not working. Really, there's not that much tech out there on automatics save for how to swap it to a manual :). Keep searching through the forums to see if there are any other threads that bear fruit.

Dale