Jump to content
SAU Community

R33 GTR speed sensor problem?

Snara
 Share

Recommended Posts

Snara Collaborator

Snara

Posted
Posted

Hi

I have problem with speed in my car. In low speed's sometimes car don't see the speed both on cluster and aftermarket ECU . I changed gearbox and speed sensor in the gearbox and still have the same problem. What else i should check?

Link to comment
https://www.sau.com.au/forums/topic/473784-r33-gtr-speed-sensor-problem/
Share on other sites
GTSBoy Grand Master

GTSBoy

Posted
Posted

Change the speedo head.

Speed signal is +/- 1V sawtooth signal from sender to speedo head.  Speedo head electronics convert that to 0-5V squarewave for the ECU etc.  If there is no display or output at low speeds but it works at high speeds, then it's probably not a broken wire or loose connection.  it is some dodgy electronics.  You could take it to an instrument specialist.  You know, like we used to do back before the internet.

  • 1 year later...
CraigoGTR33 Newbie

CraigoGTR33

Posted
Posted

Great knowledge GTSBoy.  I have a similar problem with my car although I dont have a seperate set of dials.  Perhaps  you can help?

I measured voltage at pin 53 of the ECU (speed signal in from cluster) with the car sat still and it read 4.8V,  when it was moving this value did not change.  According to the service manual it should read 5V (within 1V) and then have dropped to 2.5V at 40kmh.  Would you think this is a problem with the speedo head or the speed sensor?  Any tips to find out more? Are there some connectors in the dash that can cause hassle?  It looks like faulty connector or sensor to me but i could be wrong!

 

GTSBoy Grand Master

GTSBoy

Posted
Posted

The voltage transmitted from the speedo head to the ECU is a 0-5v square wave. It is PWM, so the pulses change width according to speed. Trying to measure that properly with a DMM is not the best idea. An oscilloscope is the best bet.

Anyway, if you have a constant 5V there it suggests that the speedo head is not doing what it is supposed to. It's unlikely to be the sensor. If you connect a mutlimeter on AC volts setting to the sensor and drive, you should see a 0.6v to 1v sort of reading.

And obviously any of the connectors in the circuits could be janky.

  • Like 1
CraigoGTR33 Newbie

CraigoGTR33

Posted
Posted

Ok ill try that test and see what readings I am getting. 

Is there any information around the speedo head that you know of?  Ive got the white nismo cluster so it'd be a shame to take them out, better to fix them if possible.  I did have them out of the car a few years back and resoldered a few places which did the trick for a while but now the problem has returned!

 

CraigoGTR33 Newbie

CraigoGTR33

Posted
Posted

Ok to update the fix.. I took the instrument cluster out on the weekend and unscrewed the speedometer from the unit. On the back is a printed circuit board (PCB).  I saw a few videos on youtube for nissans around the mid to late 90s with problems similar to mine and they suggested simply resoldering all of the solder joints on that printed circuit board. 

I did exactly that and its worked so far!  No hicas fault lights and speed reading perfectly.  Power steering is working better and the engine seems to be running smoother but Im not sure if thats true or not! 

On the first test drive around the block the tacho also stopped working so i took that out and resoldered all that PCB as well. Hopefully I dont have to take them out again for a while. 

Thanks for your help GTS Boy - you were absolutely right that the clocks were at fault rather than the speed sensor.

CraigoGTR33 Newbie

CraigoGTR33

Posted
Posted

hahaha! yeah I must admit I wasnt expecting it to work, all the solder looked fine to me.  Goes to show that visual inspections dont really count when it comes to circuit boards... just resolder everything!

And now onto the next problem on the list.... ! #skylineownership

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • PranK
      Chris' Toyota Mark ii JZX110

      By PranK · Posted

      This looks great! Awesome to have the 5 speed with an LSD in this. The Recaro's look like SR2's or SR3's. It's a shame they've been retrimmed as they would have looked sweet in their original colours. I think I'd want my agent to be a little more up front and informative too. I've never imported but I reckon it would make me a little nervous, so the more info the better.
    • soviet_merlin
      Duncan's V37.......race car?

      By soviet_merlin · Posted

      Thanks for doing that Duncan! Makes you a good person in my books. We don't get kangaroos or wombats here. But we have bats and it's similar. AFAIK it's often the mums with a baby attached that get hit because they drop lower when starting from a tree. If you hit an animal, check on it. https://www.ifaw.org/au/resources/wildlife-rescue-app An app to get the closest wildlife rescue contact.
    • Murray_Calavera
      Jacks that fit under GTR lips that can reach the subframe?

      By Murray_Calavera · Posted

      My dream is also to have a proper hoist, but I don't think it will ever happen. My quickjack is probably as close as I'll ever get, it really is very good though. 
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      Yeah we keep on in the dailies, it is pretty poor how many animals get hit and the driver leaves without checking....have saved a couple of little ones over the years. Bit of a gruesome job though, pouches generally need to be cut open because they are so tight and often the joey doesn't realise mum is gone so they are still locked onto the teat. I checked the modules in front of the DS wheel where an oil cooler should go.... There is the radar unit - that can go for race use) One of the 2 HX water pumps, the silver cylinder. That needs to be kept but might be able to be relocated But the bad news, the big computer mounted vertically in front of the wheel (blocking any potential air exit) is the electric steering computer. That is required until/unless i do a hydraulic steering conversion, and in CAD based modern car design it is not like I can just pop a big unit like that somewhere else (plus the loom would be too short anywhere else too). So, the passenger side is OK to clear out (just use a smaller washer reservoir, potentially elsewhere), but the DS no beuno
    • Duncan
      Chris' Toyota Mark ii JZX110

      By Duncan · Posted

      Well, all the best with the new camry It was interesting to hear about the UK process, it is generally a lot more streamlined here with a shipping agent looking after all the import side (noting the exact final price can still be a surprise.....) and I've used a few different brokers on the japan (or US) side, and never had any trouble with any of them....luck of the draw I guess. You mentioned you didn't get the auction sheet (understandable since you bought it from a dealer, not auction), but I always try and get hold of that because they are pretty thorough. I've imported 2x R grade vehicles over the years and both were fine, repairs in Japan are pretty thorough compared to here in Oz.
×
×
  • Create New...