Speed signal wire problems??

Well i have just connected up my apexi rsm meter and the speed and trip part is not working, always at 0, it is defo connected correctly, and also i use to have the blitz power meter on the speed signal wire, which was the pink wire on the ecu, and it never really worked, sometimes it was ok then others is was always at 0, and other times i was getting spikes on it saying bhp was 1000 ect and speed nearly 200, aslo i am now thinking that i have a bad connection or something as my overdrive off light is always flashing, so would this flash be because there is no speed input signal???

If it is not working would i expect other parts to not work as my speedo works ok, or is that part of another circuit?

Where does the pink signal input wire from the ecu go to, as i can trace it that way to see if i have a connection??

please help!!!!

Sounds like the Odometer output drive might be failing OR your speedo converter box is going t*ts up.

(That was me in technical mode)

The ODO flashing light is VERY indicative of speed signal faults and generally on Jap imports it's bad conversions.

Regards

Pete

As it happens, my speedo converter box has gone wrong in the last week. I've had the overdrive light flash and also the ECU registering code 42 (wheel speed sensor).

While the overdrive light is flashing, the cruise control doesn't work and the power steering feels over-assisted. I suspect the traction control isn't working either.

I'd be interested to know where the signal to the speedo comes from as that continues to work without a problem.

I've had a look down by the ECU and there's a box made by "Intec" attached to the ECU loom. I also had a look behind the speedo and there's no other connections that I can see, so it looks like the signal conversion is applied to everything.

Hopefully it's just a loose wire, but if not I'll probably buy the TRL box so it's converted properly.

James.

i dont have a speedo converter on my car at the moment so where does the signal wire come from as my speedo is working fine??? I have the speedo that goes up to 100 mph where it is marked out as to where the mph would be when it is running in Kph,

Its that pink wire on the ecu, isnt the speedo signal a red/blue wire??

Does the pink signal wire come from the auto gear box or something? Just want to trace it to something so i can find out what the problem is, i aslo noticed that the o/d off light starts to flash after i hit 60mph then keeps flashing at whatever speed i do after that till the engine is switched off, I only noticed it once at this speed so will try it again to see if it comes on again at 60mph, or it is totally not it!!!

what and where is the odometer output drive??

I'd be interested to know where the signal to the speedo comes from as that continues to work without a problem

The speedo gets it's signal directly from the gearbox speed sensor normally. With a converted car it will be coming from the converter.

The odometer also receives the same raw speed signal and re-broadcasts it to the rest of the car (buffered)

I've had a look down by the ECU and there's a box made by "Intec" attached to the ECU loom. I also had a look behind the speedo and there's no other connections that I can see, so it looks like the signal conversion is applied to everything.

Is yours a VVTi?

The VVTi's are converted by a box attached to the ECU. It is the ECU which converts the ABS sensor signals and sends it up to the speedo head. Different to the ordinary Jap spec car.

Its that pink wire on the ecu, isnt the speedo signal a red/blue wire??

The Speed signal comes from the sensor up the red/blue wire to the speedo head and the odometer.

The odometer buffers it and resends it out to the rest of the car via the pink (silver band) wire.

So the pink wire on the cruise, PPS and ECU are all from the odometer.

If these fail then it's likely the odometer output has failed or is failing (they are becoming more frequent for failure). The speedo with remain operational as it's unaffected by anything the odometer does.

The VVTi is different so the above it NOT true for that car.

i aslo noticed that the o/d off light starts to flash after i hit 60mph then keeps flashing at whatever speed i do after that till the engine is switched off

The speed signal failure is only logged (and thus flagged to the driver) after a period of time or over a certain speed. (Exactly when and where I do not know)

60MPH is also the speed the active spoiler deploys so

1: do you have the active spoiler?

2: does it deploy at 60MPH?

I hope some of that helped.

You can always via the on-line circuit diagrams on mkiv.com and follow the circuit yourself.

Speedo Converters

Regards

Pete

thanks for the info very interesting, yes i have a active spoiler but i dont think it works properly as never notice the green light flashing to say its down and also i have noticed that the warning triangle comes on if the spoiler does come down, so it is switched off at the moment by the auto switch on the panel.

Do you think we are getting to the problem here???

If it has failed, can it be replaced,? which bit has failed?

thanks

right, the o/d flashing starts after a certain distance as never went past 60, and i came on, my active spoiler has a mind of its own, just drove 137 miles and in the last 20 miles it decided to come down, with the warning light on???

no idea whats going on!

well thanks for the info, after having a look today and taking the odo apart i found that there was a resistor in the buffer circuit that was not resisting!! changed it and all ok, always usefull being into electronics

apexi reading my speed and hopefully now i can see if the speed cut has now gone and i can get past my limiter!!

Also didnt notice the overdrive flashing anymore so looks like i have cracked it!!

Thanks Guys,

Really helped me out. This thread belong in the faq.

Regards, Michael Mirrage

Well, I'm glad it helped you out but I can't see a thread that's lain dormant for six years being classed as a "frequently asked question"

-Ian