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Discussion Starter · #1 ·
I am new here... but I have driven my 1993 2.5l auto for 21 years now. Yes, count 'em.

Like many of you, I love my car. It has not given me much trouble over the years – however, last week I had a few times where the "Hold" light flashed up intermittently on the dash (although not engaged on gearstick) and there was a lurch as if the gears had dropped down (or an invisible foot tapped on the brake pedal as I was driving). If you drive a manuaI transmission you may not know what I am referring to. I can't say I ever use the "Hold" function myself, I imagine it might be useful if you were towing something, but I don't have a towbar.

Anyway, I kept driving and the problem resolved. Haven't experienced the problem again in three days of driving. So today my auto mechanic had a look and told me it was not good news, the error number in the log is a "55"... "Computer fail".
Has anybody else experienced anything similar? I will probably need to get the fault diagnosed accurately but wondering if anybody knows whether it would likely be a reset or a replacement?

Thanks in advance : )
 

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It is not an unusual situation to have the auto transmission suddenly go into HOLD while driving. But only once in a while.
It drops into a lower gear and won't go past that. Usually the way to resolve it is to stop the car, shift into neutral or park, then back into DRIVE. Or then turn off the engine, and start it. If this happens frequently, a lot of times it is because the motor mounts are not secure, worn out, and cause vibrations that will cause the shift into HOLD while driving. I had this problem, but not frequently. I put in a new rear motor mount, and other motor mounts, and the problem has gone completely away. The problem does not mean necessarily there is anything wrong with the transmission. Clear the HOLD log too.
 

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Discussion Starter · #3 ·
Thanks for your reply Goodbar!
OMG, first I thought "Gearbox", then the mechanic says "ECU", now it's the motor mounts! Are they expensive to replace?
To clear the HOLD log I need to reset the ECU by disconnecting negative on battery and depressing brake for XX secons, right?
 

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Yes since you already got the codes read, you can clear them as you mentioned.
It is not unusual at all for these cars to sometimes shift into HOLD mode while driving, and the gears don't shift after that. Even a few hard bumps on the road can do it. But it is nothing that can't be resolved, unless it is happening frequently.

Motor mounts are not expensive if you buy them at the aftermarket stores, and get all 5 in a package. I was shocked what they are priced at, at the dealers.

They are also not difficult to install, except for the rear motor mount. That one is difficult, but can be done with the correct tools and some patience.
 

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I am new here... but I have driven my 1993 2.5l auto for 21 years now. Yes, count 'em.

Like many of you, I love my car. It has not given me much trouble over the years – however, last week I had a few times where the "Hold" light flashed up intermittently on the dash (although not engaged on gearstick) and there was a lurch as if the gears had dropped down (or an invisible foot tapped on the brake pedal as I was driving). If you drive a manuaI transmission you may not know what I am referring to. I can't say I ever use the "Hold" function myself, I imagine it might be useful if you were towing something, but I don't have a towbar.

Anyway, I kept driving and the problem resolved. Haven't experienced the problem again in three days of driving. So today my auto mechanic had a look and told me it was not good news, the error number in the log is a "55"... "Computer fail".
Has anybody else experienced anything similar? I will probably need to get the fault diagnosed accurately but wondering if anybody knows whether it would likely be a reset or a replacement?

Thanks in advance : )
that sounds horribly like the problems I've just been through. Hold light flashed and the engine cut out, sometimes for a moment, sometimes for 10 minutes. Some days it would do it some days it didn't. After changing all sorts of ignition sensors and two trips to the auto electrician it turned out to be three 25c capacitors in the ECU (engine computer)
The capacitors had started to die with heat and old age and were leaking their corrosive contents on to the circuit board and starting to corrode the tracks.
Easily repairable by a competent electronics tech but I got an exchange unit. Haven't looked back since.
Cheers, Phil.
 

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Discussion Starter · #7 ·
OMG... that's the problem – it could be this, it could be that, it could be the other. My auto mechanic feels it's the speed sensor (fairly inexpensive) so he has got a replacement part and we'll try that. Otherwise I have spoken to a tame auto electrician who will look at the ECU if nothing changes. My engine doesn't cut out though. It just stays stuck in low gear – but so far this fault only happens when I am driving fast, i.e. on the motorway, so I can't slow down! When I do slow down, it goes back to normal. Cars!!
Thanks for your post Phil, I will keep that in mind if a trip to the sparky eventuates. All this information is invaluable because I don't know a nut from a bolt!
: )
 

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Discussion Starter · #8 ·
I also think the worst thing to happen to cars is the ECU! So much simpler when everything was mechanical!! Damn robots.
 

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Only thing I can add is I had the exact same problem you describe. After I replaced the rear motor mount, it has not happened once since then. I don't believe it has anything to do with your speed sensor or ECU. I have replaced my speed sensor and turbine sensor several times in the past.
 

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Discussion Starter · #10 ·
I mentioned that to my mechanic and he thought the engine mounts looked OK... I'll let him do the speed sensor and see what happens! I dunno! Probably end up trying everything!
I appreciate your help Goodbar : ) How long have you been driving your 6?
 

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You can't even see the condition of the rear motor mount because of the location. The other 4 are easy to see, and quite easy to replace. I am the original owner and now on my 3rd engine and transmission. It has 300,000 miles. I do all the mechanical work myself.
 

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Discussion Starter · #12 ·
Well, just following up -- a little late because I was waiting to see if this fix held. So far it has... and it turned out to be the speed sensor. Had that replaced and the car is running beautifully! Part was about NZ$185 and labour a bit less. Happy ending!!! Thanks : )
 

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That is good news. Curious as to which speed sensor you replaced......the one for the transmission, or the one that provides speedometer readings. They are both called speed sensors. At the price you mention, that would sound more like the one for the speedometer. The one for the transmission is only about $ 30 usd, and takes about 15 minutes to install it. Here is a photo of the transmission speed sensor.
 

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Discussion Starter · #14 ·
You know, I have no idea. Cars are not my thing! I'm strictly two-dimensional : )
In other news, the 4WS light came on briefly yesterday. Steering felt normal and it didn't stay on all day. It's an old car and I know it's not going to last forever. I feel these are the niggles of old age come upon her. I get them too.
 

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Discussion Starter · #16 ·
Googled this:
Input/Turbine Speed Sensor Circuit Trouble Code
An input/turbine speed sensor / turbine speed sensor / TSS is an electromagnetic device that the engine control unit (ECU) uses to monitor the transmission input shaft speed/RPM. If a TSS trouble code is present, it means that the signal coming from the transmission input speed sensor does not meet the computer’s programmed parameters.
How Serious is the Code?
The seriousness of a TSS trouble code depends on the vehicle. Some automatic transmissions will continue to operate normally. While others will shift erratically, or not at all.
Symptoms
  • Check engine light
  • Erratic or hard shifts
  • Failure to shift
  • Decreased fuel economy
  • Speedometer/odometer failure or fluctuation
  • Engine stalling
  • Limp Mode
 
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