~Rev Free~

I have had a problem where the tachometer drops to 0 while driving, also the TC light comes on and stays on. I have checked for codes using my Scan Gauge, but nothing comes up.

First time it happened I was in the canyons doing some spirited driving downhill, and I see a flash from the cluster, and when I look down the tachometer is at 0, but the car is still operating normally. It happens several times again during the run, shooting down to 0 and coming right back up. I get to the bottom, shut off the engine, wait, and restart it. After that, everything was normal.

Second time it happened, I was cruising on the freeway at 70 with cruise control on, tachometer shoots to 0, but the car keeps up speed, only thing that happens, is that the cruise control light goes off, then comes back on when the needle resumes position.

The car is a 2004, manual, with 109,xxx miles.

Another issue that came up, was while I was entering the freeway, the Parking Brake light, TC light, and ABS light illuminated, no problems were found in driving feel or anything, as well as no codes.

swoope

iTrader: (5)

check / clean / tighten the battery cables. then get the battery tested..

beers

~Rev Free~

Thanks for the advice, I will check it out.. Could you explain to me your reasoning behind your suggestion though?

swoope

iTrader: (5)

have seen it before, also you are going to want to check your connector for the power steering. it is under the airbox, it is also a known issue. if you look around here a bit you will find the info.

beers

~Rev Free~

Oh okay, thanks, I appreciate it. I haven't seen or heard of this problem on any other cars before, so it caught me by surprise. Could you point me in the right direction as to what to search for? I looked up "tachometer failure, etc" didn't find anything.

swoope

iTrader: (5)

not something you would likely find with even a very good search. it has happened a few times. it is one of those i read and retain to much things.. notice you did not get the search newb on this..

and someone i know is going through it right now. same symptoms.. but his battery is bad..

as to the power steering. this will help.

https://www.rx8club.com/series-i-trouble-shooting-95/power-steering-failure-107481/

you dont have to solder it. a good cleaning tends to take care of it. some waterproofing will help.

beers

Shifty Devil

It may be your ScanGauge. If you have selected a custom color of the backlight change it back to a single color, white or red, etc. When I got mine and first tried using it I was getting similar gauge problems. Someone else that had the same problem noticed it only happened with custom colors, that when he chose one plain color the problem went away. I believe the custom color uses multiple LEDs and the power draw on the CAN bus is just a little too much for the circuit. One color most likely uses a single LED (I'm guessing here since I never opened mine up) and lowers the power requirements. I had initially exchanged mine because of the problem and the second unit did the same thing. The current draw of the gauge lighting seems to be just beyond what the CAN circuits may be designed to handle.

MazdaManiac

iTrader: (3)

Yeah, what Swoope said.
A significant drop in available current on the charging system and/or a short will do this.

Also, a plug wire shorting to the chassis (bad wire) will cause similar symptoms.