Code 42??? What next??

[cara-croft]

: Sorry everyone,

Its me again.
Desperate now for some help, so starting new thread from no speedo, no rev counter....

I have done a diagnostic as O/D light started flashing and searched the forum for what that was all about.

Got a code 42 which is apparently no1 speed sensor circuit.... but this means nothing to me, what do I do next, where is it, what is it etc??

Please help

Cara

[TonyN]

ok, its telling you there is no signal from the speed sensor, there are 2 or 3 on the gearbox.

but you'll get the same result from a break in the wire, so don't rush out and buy the sensor unless you're sure the wiring behind dash is ok, or you could be wasting your cash.

did you ever look for the speedo converter gismo and check its wiring like we talked about behind hte dash?

[cara-croft]

Thanks for replying Tony, sorry I didn't see your reply as I've been backwards and forwards to the car.

I did check the back of the dash and the plug behind the speedometer has 4 wires which are spliced into and a little box is there, so I presumed this was the converter. I have pushed all the plugs in that join the wires and the wires look ok in the main plug in the dash, all the contacts look fine, so don't really know what else to check.

All I do know is that it must be something to do with the instrument panel because this only happened because I took the dash out to reset the timing belt counter and everything was fine before that!!

I seem to be losing more functions everytime I take the dash out!!! Now I have no temperature guage or fuel guage, indicator lights are also playing up (the actual indicators are fine and I can hear them) and as before no speedo or rev counter.

Thanks again Tony
Cara

[Albannach]

Sounds like you're not plugging things back in correctly. If the spedo is not there or not wired correctly, you'll get that error (I did). Mine was a broken track on the speedo's PCB.

[cara-croft]

Thanks andy, I've checked every wire over and over again I've looked carefully at circuits on back of clocks and can not see any visible damage but then again is it that easy to see? !!!!
All I know is every time I take these blimming clocks out something else dont work !!! tomorrow is my last day because I'm off to Devon Thursday will anything else disappear off my dash !!!
In hope of a safe return
Cara

[cara-croft]

Back From Holiday!!

Hi Everyone,
I'm back from holiday in one piece!!

I still have no guages!! Nothing has altered in 1500 miles!! Good job I can rely on the Surf not to overheat when towing!!

Andy, you mentioned the PCB, I take it that is the part on the back of the instrument panel with the circuits on. Would you know of anywhere I can get a diagram that explains what all the circuit tracks do and what all the wires in the 3 plugs do? Also, how did you fix your problem exactly, in the end?

Also, is there a way of testing these circuits and can I be sure of doing the tests without frying them!!??

Thanks for any help with this

Cara

[MattF]

Get a VOM and test the tracks for continuity.

[Apache]

I have no speedo, and am suspecting the sensor or a break somewhere between the sensor and the ECU.

Both speed sensors feed the ECU on an auto truck, then the output of one (I assume) goes to the speedo. If it went straight to the speedo without going via the ECU, then the ECU wouldn't flag up an error if it failed as it wouldn't know...

You (I think) have no instruments, so I would be looking for a power supply problem around the instrument pod.

[cara-croft]

Thank you both for your replies.

I'm now looking at Halfords, at their Multi meters, as you suggested Matt. I think I will go and get one tomorrow to see if I can get any closer to sorting this out.

I am presuming the same as you Andy, as I got the code 42 I don't think it is the speed sensors itself but a break in the circuit, like you said.

Still not sure which parts to test, so if anyone has a diagram or picture with the names of the circuits on it, that I can understand, it would be great (It probably doesn't exist!) ??

Thanks Again

Cara

[MattF]

Looking at a schematic will be more confusing than just tracing the tracks on the back of the unit. Just follow each track from the multi-plug(s) and check that you have continuity between each pin and its far end point of the track. The tracks are easily visible.

[cara-croft]

Thanks for that Matt, at least I can go to bed a bit more happier now!!

I will let you know how I get on with it

Cara

[Apache]

Looking at a schematic will be more confusing than just tracing the tracks on the back of the unit.

But it will help me.

If the signal from each of the speed sensors goes direct to the ecu, then one goes out to the speedo, then the ECU could flag up a duff speedo sensor. Assuming a broken track in the instrument pod is causing the problem, infers that the speedo sensor data goes via the instrument pod to the ECU - which seems like cr@p design to me.

Do you have a diagram that confirms this on your server? The only ones I've seen are the ECU diagram (just has two speedo sensor I/Ps, doesn't indicate where from) and an overall wiring diagram which doesn't appear to show two speedo I/Ps so is probably a MT ECU...

[cara-croft]

Right......

I have bought a Gunson Pocket Meter from Halfords tonight and spoke to one of the guys there who showed me how to check the circuits, very helpful young man!!!

I've taken the clocks out, once I got back, so will let you know what happens next......:

Lets hope its not
or it could mean


Cara

[stormforce]

Cara if you want to cover the postage i have a working set of 2nd gen 3.0l clocks here you can try out if you want.If you want to keep them then you can pay for them if not send them back again.Let me know and i'll sort them in the next couple of days

scrap that i have just looked and you got a 3rd gen

[cara-croft]

Well the meter didn't work how I expected. I have checked the circuits from the plug, behind the speedometer ( without the plug actually in it as the instrument panel is sitting on the desk here with me now) to the various points such as "sen" and got readings which I didn't understand.......
but ..... I presume any reading means there is continuity there! Am I right?

Can anyone tell me where to go next with this?

Thankyou

Cara